human respiratory system assignment

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Human Respiratory System

Respiratory system of humans.

Breathing involves gaseous exchange through inhalation and exhalation. The human respiratory system has the following main structures – Nose, mouth, pharynx, larynx, trachea, bronchi, and lungs. Explore in detail.

Table of Contents

• What Is Respiratory System

Respiratory Tract

Respiratory system definition.

“Human Respiratory System is a network of organs and tissues that helps us breathe. The primary function of this system is to introduce oxygen into the body and expel carbon dioxide from the body.”

What is the Respiratory System?

As defined above, the human respiratory system consists of a group of organs and tissues that help us to breathe. Aside from the lungs, there are also muscles and a vast network of blood vessels that facilitate the process of respiration.

Also Read:  Mechanism of Breathing

Human Respiratory System Diagram

To gain a clearer understanding, we have illustrated the human respiratory system and its different parts involved in the process.

Human Respiratory System Diagram showing different parts of the Respiratory Tract

Features of the Human Respiratory System

The respiratory system in humans has the following important features:

• The energy is generated by the breakdown of glucose molecules in all living cells of the human body.
• Oxygen is inhaled and is transported to various parts and are used in the process of burning food particles (breaking down glucose molecules) at the cellular level in a series of chemical reactions.
• The obtained glucose molecules are used for discharging energy in the form of ATP- (adenosine triphosphate)

Also Read:  Difference between trachea and oesophagus

Respiratory System Parts and Functions

Let us have a detailed look at the different parts of the respiratory system and their functions.

Humans have exterior nostrils, which are divided by a framework of cartilaginous structure called the septum. This is the structure that separates the right nostril from the left nostril. Tiny hair follicles that cover the interior lining of nostrils act as the body’s first line of defence against foreign pathogens . Furthermore, they provide additional humidity for inhaled air.

Two cartilaginous chords lay the framework for the larynx. It is found in front of the neck and is responsible for vocals as well as aiding respiration. Hence, it is also informally called the voice box. When food is swallowed, a flap called the epiglottis folds over the top of the windpipe and prevents food from entering into the larynx.

Also check: What is the role of epiglottis and diaphragm in respiration?

The nasal chambers open up into a wide hollow space called the pharynx. It is a common passage for air as well as food. It functions by preventing the entry of food particles into the windpipe. The epiglottis is an elastic cartilage, which serves as a switch between the larynx and the oesophagus by allowing the passage of air into the lungs, and food in the  gastrointestinal tract .

Have you ever wondered why we cough when we eat or swallow?

Talking while we eat or swallow may sometimes result in incessant coughing. The reason behind this reaction is the epiglottis. It is forced to open for the air to exit outwards and the food to enter into the windpipe, triggering a cough.

The trachea or the windpipe rises below the larynx and moves down to the neck. The walls of the trachea comprise C-shaped cartilaginous rings which give hardness to the trachea and maintain it by completely expanding. The trachea extends further down into the breastbone and splits into two bronchi, one for each lung.

The trachea splits into two tubes called the bronchi, which enter each lung individually. The bronchi divide into secondary and tertiary bronchioles, and it further branches out into small air-sacs called the alveoli. The alveoli are single-celled sacs of air with thin walls. It facilitates the exchange of oxygen and carbon dioxide molecules into or away from the bloodstream.

Lungs are the primary organs of respiration in humans and other vertebrates. They are located on either side of the heart, in the thoracic cavity of the chest. Anatomically, the lungs are spongy organs with an estimates total surface area between 50 to 75 sq meters. The primary function of the lungs is to facilitate the exchange of gases between the blood and the air. Interestingly, the right lung is quite bigger and heavier than the left lung.

Also Read:  Respiration

The respiratory tract in humans is made up of the following parts:

• External nostrils – For the intake of air.
• Nasal chamber – which is lined with hair and mucus to filter the air from dust and dirt.
• Pharynx – It is a passage behind the nasal chamber and serves as the common passageway for both air and food.
• Larynx – Known as the soundbox as it houses the vocal chords, which are paramount in the generation of sound.
• Epiglottis – It is a flap-like structure that covers the glottis and prevents the entry of food into the windpipe.
• Trachea – It is a long tube passing through the mid-thoracic cavity.
• Bronchi – The trachea divides into left and right bronchi.
• Bronchioles – Each bronchus is further divided into finer channels known as bronchioles.
• Alveoli – The bronchioles terminate in balloon-like structures known as the alveoli.
• Lungs – Humans have a pair of lungs, which are sac-like structures and covered by a double-layered membrane known as pleura.

Air is inhaled with the help of nostrils, and in the nasal cavity, the air is cleansed by the fine hair follicles present within them. The cavity also has a group of blood vessels that warm the air. This air then passes to the pharynx, then to the larynx and into the trachea.

The trachea and the bronchi are coated with ciliated epithelial cells and goblet cells (secretory cells) which discharge mucus to moisten the air as it passes through the respiratory tract. It also traps the fine bits of dust or pathogen that escaped the hair in the nasal openings. The motile cilia beat in an ascending motion, such that the mucus and other foreign particles are carried back to the buccal cavity where it may either be coughed out (or swallowed.)

Once the air reaches the bronchus, it moves into the bronchioles, and then into the alveoli.

Respiratory System Functions

The functions of the human respiratory system are as follows:

Inhalation and Exhalation

The respiratory system helps in breathing (also known as pulmonary ventilation.) The air inhaled through the nose moves through the pharynx, larynx, trachea and into the lungs. The air is exhaled back through the same pathway. Changes in the volume and pressure in the lungs aid in pulmonary ventilation.

Exchange of Gases between Lungs and Bloodstream

Inside the lungs, the oxygen and carbon dioxide enter and exit respectively through millions of microscopic sacs called alveoli. The inhaled oxygen diffuses into the pulmonary capillaries, binds to haemoglobin and is pumped through the bloodstream. The carbon dioxide from the blood diffuses into the alveoli and is expelled through exhalation.

Also read: Exchange Of Gases in Plants

Exchange of Gases between Bloodstream and Body Tissues

The blood carries the oxygen from the lungs around the body and releases the oxygen when it reaches the capillaries. The oxygen is diffused through the capillary walls into the body tissues. The carbon dioxide also diffuses into the blood and is carried back to the lungs for release.

The Vibration of the Vocal Cords

While speaking, the muscles in the larynx move the arytenoid cartilage. These cartilages push the vocal cords together. During exhalation, when the air passes through the vocal cords, it makes them vibrate and creates sound.

Olfaction or Smelling

During inhalation, when the air enters the nasal cavities, some chemicals present in the air bind to it and activate the receptors of the nervous system on the cilia. The signals are sent to the olfactory bulbs via the brain.

Also Read:  Respiratory System Disorders

Respiration is one of the metabolic processes which plays an essential role in all living organisms. However, lower organisms like the unicellular do not “breathe” like humans – intead, they utilise the process of diffusion. Annelids like earthworms have a moist cuticle which helps them in gaseous exchange. Respiration in fish occurs through special organs called gills. Most of the higher organisms possess a pair of lungs for breathing.

Also Read:  Amphibolic Pathway

To learn more about respiration, check out the video below:

Frequently Asked Questions

What is the human respiratory system.

The human respiratory system is a system of organs responsible for inhaling oxygen and exhaling carbon dioxide in humans. The important respiratory organs in living beings include- lungs, gills, trachea, and skin.

What are the important respiratory system parts in humans?

The important human respiratory system parts include- Nose, larynx, pharynx, trachea, bronchi and lungs.

What is the respiratory tract made up of?

The respiratory tract is made up of nostrils, nasal chamber, larynx, pharynx, epiglottis, trachea, bronchioles, bronchi, alveoli, and lungs.

What are the main functions of the respiratory system?

The important functions of the respiratory system include- inhalation and exhalation of gases, exchange of gases between bloodstream and lungs, the gaseous exchange between bloodstream and body tissues, olfaction and vibration of vocal cords.

What are the different types of respiration in humans?

The different types of respiration in humans include- internal respiration, external respiration and cellular respiration. Internal respiration includes the exchange of gases between blood and cells, external respiration is the breathing process, whereas cellular respiration is the metabolic reactions taking place in the cells to produce energy.

What are the different stages of aerobic respiration?

Aerobic respiration is the process of breaking down glucose to produce energy. It occurs in the following different stages- glycolysis, pyruvate oxidation, citric acid cycle or Krebs cycle, and electron transport system.

Why do the cells need oxygen?

Our body cells require oxygen to release energy. The oxygen inhaled during respiration is used to break down the food to release energy.

What is the main difference between breathing and respiration in humans?

Breathing is the physical process of inhaling oxygen and exhaling carbon dioxide in and out of our lungs. On the contrary, respiration is the chemical process where oxygen is utilized to break down glucose to generate energy to carry out different cellular processes.

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Top 5 Functions of the Respiratory System: A Look Inside Key Respiratory Activities

Through breathing, inhalation and exhalation, the respiratory system facilitates the exchange of gases between the air and the blood and between the blood and the body’s cells. The respiratory system also helps us to smell and create sound. The following are the five key functions of the respiratory system.

Breathing In and Speaking Out: How the Structures of the Upper Respiratory System Work

The structures of the upper respiratory system, or respiratory tract, allow us to breathe and speak.

• The nose and nasal cavities provide airways for respiration.
• The paranasal sinuses surround the nasal cavities.
• The pharynx connects the nasal and oral cavities to the larynx and esophagus.
• The larynx and vocal cords allow us to breathe and talk and sing.
• Structures that produce sound depend on the hyoid bone.

Drawing In and Processing Air: Functions of the Trachea, Bronchi, Lungs, and Alveoli

• Trachea: the main airway to the lungs
• Bronchi: passageways that bring air in and out of the lungs
• Lungs: structures responsible for gas exchange between the air we breathe and our bodies
• Alveoli: microscopic air sacs that are the site of external respiration
• Diaphragm: the muscle that is key to the physical process of breathing

Common Respiratory Diseases and Disorders: COPD, Asthma, Sinusitis, Influenza, and Pneumothorax

• Most respiratory diseases and disorders can be described as either infectious or chronic.
• Inflamed airways become irritated during inhalation during an asthma attack.
• Sinusitis is the inflammation of mucous membranes in the nasal sinuses.
• The flu virus can pass through the air from one person to another.
• Chest trauma can cause pneumothorax, a collapsed lung.

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22.1 Organs and Structures of the Respiratory System

Learning objectives.

By the end of this section, you will be able to:

• List the structures that make up the respiratory system
• Describe how the respiratory system processes oxygen and CO 2
• Compare and contrast the functions of upper respiratory tract with the lower respiratory tract

The major organs of the respiratory system function primarily to provide oxygen to body tissues for cellular respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance. Portions of the respiratory system are also used for non-vital functions, such as sensing odors, speech production, and for straining, such as during childbirth or coughing ( Figure 22.2 ).

Functionally, the respiratory system can be divided into a conducting zone and a respiratory zone. The conducting zone of the respiratory system includes the organs and structures not directly involved in gas exchange. The gas exchange occurs in the respiratory zone .

Conducting Zone

The major functions of the conducting zone are to provide a route for incoming and outgoing air, remove debris and pathogens from the incoming air, and warm and humidify the incoming air. Several structures within the conducting zone perform other functions as well. The epithelium of the nasal passages, for example, is essential to sensing odors, and the bronchial epithelium that lines the lungs can metabolize some airborne carcinogens.

The Nose and its Adjacent Structures

The major entrance and exit for the respiratory system is through the nose. When discussing the nose, it is helpful to divide it into two major sections: the external nose, and the nasal cavity or internal nose.

The external nose consists of the surface and skeletal structures that result in the outward appearance of the nose and contribute to its numerous functions ( Figure 22.3 ). The root is the region of the nose located between the eyebrows. The bridge is the part of the nose that connects the root to the rest of the nose. The dorsum nasi is the length of the nose. The apex is the tip of the nose. On either side of the apex, the nostrils are formed by the alae (singular = ala). An ala is a cartilaginous structure that forms the lateral side of each naris (plural = nares), or nostril opening. The philtrum is the concave surface that connects the apex of the nose to the upper lip.

Underneath the thin skin of the nose are its skeletal features (see Figure 22.3 , lower illustration). While the root and bridge of the nose consist of bone, the protruding portion of the nose is composed of cartilage. As a result, when looking at a skull, the nose is missing. The nasal bone is one of a pair of bones that lies under the root and bridge of the nose. The nasal bone articulates superiorly with the frontal bone and laterally with the maxillary bones. Septal cartilage is flexible hyaline cartilage connected to the nasal bone, forming the dorsum nasi. The alar cartilage consists of the apex of the nose; it surrounds the naris.

The nares open into the nasal cavity, which is separated into left and right sections by the nasal septum ( Figure 22.4 ). The nasal septum is formed anteriorly by a portion of the septal cartilage (the flexible portion you can touch with your fingers) and posteriorly by the perpendicular plate of the ethmoid bone (a cranial bone located just posterior to the nasal bones) and the thin vomer bones (whose name refers to its plough shape). Each lateral wall of the nasal cavity has three bony projections, called the superior, middle, and inferior nasal conchae. The inferior conchae are separate bones, whereas the superior and middle conchae are portions of the ethmoid bone. Conchae serve to increase the surface area of the nasal cavity and to disrupt the flow of air as it enters the nose, causing air to bounce along the epithelium, where it is cleaned and warmed. The conchae and meatuses also conserve water and prevent dehydration of the nasal epithelium by trapping water during exhalation. The floor of the nasal cavity is composed of the palate. The hard palate at the anterior region of the nasal cavity is composed of bone. The soft palate at the posterior portion of the nasal cavity consists of muscle tissue. Air exits the nasal cavities via the internal nares and moves into the pharynx.

Several bones that help form the walls of the nasal cavity have air-containing spaces called the paranasal sinuses, which serve to warm and humidify incoming air. Sinuses are lined with a mucosa. Each paranasal sinus is named for its associated bone: frontal sinus, maxillary sinus, sphenoidal sinus, and ethmoidal sinus. The sinuses produce mucus and lighten the weight of the skull.

The nares and anterior portion of the nasal cavities are lined with mucous membranes, containing sebaceous glands and hair follicles that serve to prevent the passage of large debris, such as dirt, through the nasal cavity. An olfactory epithelium used to detect odors is found deeper in the nasal cavity.

The conchae, meatuses, and paranasal sinuses are lined by respiratory epithelium composed of pseudostratified ciliated columnar epithelium ( Figure 22.5 ). The epithelium contains goblet cells, one of the specialized, columnar epithelial cells that produce mucus to trap debris. The cilia of the respiratory epithelium help remove the mucus and debris from the nasal cavity with a constant beating motion, sweeping materials towards the throat to be swallowed. Interestingly, cold air slows the movement of the cilia, resulting in accumulation of mucus that may in turn lead to a runny nose during cold weather. This moist epithelium functions to warm and humidify incoming air. Capillaries located just beneath the nasal epithelium warm the air by convection. Serous and mucus-producing cells also secrete the lysozyme enzyme and proteins called defensins, which have antibacterial properties. Immune cells that patrol the connective tissue deep to the respiratory epithelium provide additional protection.

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The pharynx is a tube formed by skeletal muscle and lined by mucous membrane that is continuous with that of the nasal cavities (see Figure 22.4 ). The pharynx is divided into three major regions: the nasopharynx, the oropharynx, and the laryngopharynx ( Figure 22.6 ).

The nasopharynx is flanked by the conchae of the nasal cavity, and it serves only as an airway. At the top of the nasopharynx are the pharyngeal tonsils. A pharyngeal tonsil , also called an adenoid, is an aggregate of lymphoid reticular tissue similar to a lymph node that lies at the superior portion of the nasopharynx. The function of the pharyngeal tonsil is not well understood, but it contains a rich supply of lymphocytes and is covered with ciliated epithelium that traps and destroys invading pathogens that enter during inhalation. The pharyngeal tonsils are large in children, but interestingly, tend to regress with age and may even disappear. The uvula is a small bulbous, teardrop-shaped structure located at the apex of the soft palate. Both the uvula and soft palate move like a pendulum during swallowing, swinging upward to close off the nasopharynx to prevent ingested materials from entering the nasal cavity. In addition, auditory (Eustachian) tubes that connect to each middle ear cavity open into the nasopharynx. This connection is why colds often lead to ear infections.

The oropharynx is a passageway for both air and food. The oropharynx is bordered superiorly by the nasopharynx and anteriorly by the oral cavity. The fauces is the opening at the connection between the oral cavity and the oropharynx. As the nasopharynx becomes the oropharynx, the epithelium changes from pseudostratified ciliated columnar epithelium to stratified squamous epithelium. The oropharynx contains two distinct sets of tonsils, the palatine and lingual tonsils. A palatine tonsil is one of a pair of structures located laterally in the oropharynx in the area of the fauces. The lingual tonsil is located at the base of the tongue. Similar to the pharyngeal tonsil, the palatine and lingual tonsils are composed of lymphoid tissue, and trap and destroy pathogens entering the body through the oral or nasal cavities.

The laryngopharynx is inferior to the oropharynx and posterior to the larynx. It continues the route for ingested material and air until its inferior end, where the digestive and respiratory systems diverge. The stratified squamous epithelium of the oropharynx is continuous with the laryngopharynx. Anteriorly, the laryngopharynx opens into the larynx, whereas posteriorly, it enters the esophagus.

The larynx is a cartilaginous structure inferior to the laryngopharynx that connects the pharynx to the trachea and helps regulate the volume of air that enters and leaves the lungs ( Figure 22.7 ). The structure of the larynx is formed by several pieces of cartilage. Three large cartilage pieces—the thyroid cartilage (anterior), epiglottis (superior), and cricoid cartilage (inferior)—form the major structure of the larynx. The thyroid cartilage is the largest piece of cartilage that makes up the larynx. The thyroid cartilage consists of the laryngeal prominence , or “Adam’s apple,” which tends to be more prominent in males. The thick cricoid cartilage forms a ring, with a wide posterior region and a thinner anterior region. Three smaller, paired cartilages—the arytenoids, corniculates, and cuneiforms—attach to the epiglottis and the vocal cords and muscle that help move the vocal cords to produce speech.

The epiglottis , attached to the thyroid cartilage, is a very flexible piece of elastic cartilage that covers the opening of the trachea (see Figure 22.4 ). When in the “closed” position, the unattached end of the epiglottis rests on the glottis. The glottis is composed of the vestibular folds, the true vocal cords, and the space between these folds ( Figure 22.8 ). A vestibular fold , or false vocal cord, is one of a pair of folded sections of mucous membrane. A true vocal cord is one of the white, membranous folds attached by muscle to the thyroid and arytenoid cartilages of the larynx on their outer edges. The inner edges of the true vocal cords are free, allowing oscillation to produce sound. The size of the membranous folds of the true vocal cords differs between individuals, producing voices with different pitch ranges. Folds in males tend to be larger than those in females, which create a deeper voice. The act of swallowing causes the pharynx and larynx to lift upward, allowing the pharynx to expand and the epiglottis of the larynx to swing downward, closing the opening to the trachea. These movements produce a larger area for food to pass through, while preventing food and beverages from entering the trachea.

Continuous with the laryngopharynx, the superior portion of the larynx is lined with stratified squamous epithelium, transitioning into pseudostratified ciliated columnar epithelium that contains goblet cells. Similar to the nasal cavity and nasopharynx, this specialized epithelium produces mucus to trap debris and pathogens as they enter the trachea. The cilia beat the mucus upward towards the laryngopharynx, where it can be swallowed down the esophagus.

The trachea (windpipe) extends from the larynx toward the lungs ( Figure 22.9 a ). The trachea is formed by 16 to 20 stacked, C-shaped pieces of hyaline cartilage that are connected by dense connective tissue. The trachealis muscle and elastic connective tissue together form the fibroelastic membrane , a flexible membrane that closes the posterior surface of the trachea, connecting the C-shaped cartilages. The fibroelastic membrane allows the trachea to stretch and expand slightly during inhalation and exhalation, whereas the rings of cartilage provide structural support and prevent the trachea from collapsing. In addition, the trachealis muscle can be contracted to force air through the trachea during exhalation. The trachea is lined with pseudostratified ciliated columnar epithelium, which is continuous with the larynx. The esophagus borders the trachea posteriorly.

Bronchial Tree

The trachea branches into the right and left primary bronchi at the carina. These bronchi are also lined by pseudostratified ciliated columnar epithelium containing mucus-producing goblet cells ( Figure 22.9 b ). The carina is a raised structure that contains specialized nervous tissue that induces violent coughing if a foreign body, such as food, is present. Rings of cartilage, similar to those of the trachea, support the structure of the bronchi and prevent their collapse. The primary bronchi enter the lungs at the hilum, a concave region where blood vessels, lymphatic vessels, and nerves also enter the lungs. The bronchi continue to branch into a bronchial tree. A bronchial tree (or respiratory tree) is the collective term used for these multiple-branched bronchi. The main function of the bronchi, like other conducting zone structures, is to provide a passageway for air to move into and out of each lung. In addition, the mucous membrane traps debris and pathogens.

A bronchiole branches from the tertiary bronchi. Bronchioles, which are about 1 mm in diameter, further branch until they become the tiny terminal bronchioles, which lead to the structures of gas exchange. There are more than 1000 terminal bronchioles in each lung. The muscular walls of the bronchioles do not contain cartilage like those of the bronchi. This muscular wall can change the size of the tubing to increase or decrease airflow through the tube.

Respiratory Zone

In contrast to the conducting zone, the respiratory zone includes structures that are directly involved in gas exchange. The respiratory zone begins where the terminal bronchioles join a respiratory bronchiole , the smallest type of bronchiole ( Figure 22.10 ), which then leads to an alveolar duct, opening into a cluster of alveoli.

An alveolar duct is a tube composed of smooth muscle and connective tissue, which opens into a cluster of alveoli. An alveolus is one of the many small, grape-like sacs that are attached to the alveolar ducts.

An alveolar sac is a cluster of many individual alveoli that are responsible for gas exchange. An alveolus is approximately 200 μm in diameter with elastic walls that allow the alveolus to stretch during air intake, which greatly increases the surface area available for gas exchange. Alveoli are connected to their neighbors by alveolar pores , which help maintain equal air pressure throughout the alveoli and lung ( Figure 22.11 ).

The alveolar wall consists of three major cell types: type I alveolar cells, type II alveolar cells, and alveolar macrophages. A type I alveolar cell is a squamous epithelial cell of the alveoli, which constitute up to 97 percent of the alveolar surface area. These cells are about 25 nm thick and are highly permeable to gases. A type II alveolar cell is interspersed among the type I cells and secretes pulmonary surfactant , a substance composed of phospholipids and proteins that reduces the surface tension of the alveoli. Roaming around the alveolar wall is the alveolar macrophage , a phagocytic cell of the immune system that removes debris and pathogens that have reached the alveoli.

The simple squamous epithelium formed by type I alveolar cells is attached to a thin, elastic basement membrane. This epithelium is extremely thin and borders the endothelial membrane of capillaries. Taken together, the alveoli and capillary membranes form a respiratory membrane that is approximately 0.5 μm (micrometers) thick. The respiratory membrane allows gases to cross by simple diffusion, allowing oxygen to be picked up by the blood for transport and CO 2 to be released into the air of the alveoli.

Diseases of the...

Respiratory system: asthma.

Asthma is common condition that affects the lungs in both adults and children. Approximately 8.2 percent of adults (18.7 million) and 9.4 percent of children (7 million) in the United States suffer from asthma. In addition, asthma is the most frequent cause of hospitalization in children.

Asthma is a chronic disease characterized by inflammation and edema of the airway, and bronchospasms (that is, constriction of the bronchioles), which can inhibit air from entering the lungs. In addition, excessive mucus secretion can occur, which further contributes to airway occlusion ( Figure 22.12 ). Cells of the immune system, such as eosinophils and mononuclear cells, may also be involved in infiltrating the walls of the bronchi and bronchioles.

Bronchospasms occur periodically and lead to an “asthma attack.” An attack may be triggered by environmental factors such as dust, pollen, pet hair, or dander, changes in the weather, mold, tobacco smoke, and respiratory infections, or by exercise and stress.

Symptoms of an asthma attack involve coughing, shortness of breath, wheezing, and tightness of the chest. Symptoms of a severe asthma attack that requires immediate medical attention would include difficulty breathing that results in blue (cyanotic) lips or face, confusion, drowsiness, a rapid pulse, sweating, and severe anxiety. The severity of the condition, frequency of attacks, and identified triggers influence the type of medication that an individual may require. Longer-term treatments are used for those with more severe asthma. Short-term, fast-acting drugs that are used to treat an asthma attack are typically administered via an inhaler. For young children or individuals who have difficulty using an inhaler, asthma medications can be administered via a nebulizer.

In many cases, the underlying cause of the condition is unknown. However, recent research has demonstrated that certain viruses, such as human rhinovirus C (HRVC), and the bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae that are contracted in infancy or early childhood, may contribute to the development of many cases of asthma.

Visit this site to learn more about what happens during an asthma attack. What are the three changes that occur inside the airways during an asthma attack?

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21 The Respiratory System

Dialogue cards, question sets.

Major Respiratory System Organs

Respiratory Epithelium

Regions of the Pharynx

Respiratory Membrane and Alveoli

The Process of Breathing

Ventilation Control Centers

Interactive Activities for Human Anatomy and Physiology Copyright © by Open Education Lab is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

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Respiratory System Anatomy and Physiology

Breathe life into your understanding with our guide on the respiratory system anatomy and physiology. Nursing students, immerse yourself in the intricate dance of inhalation and exhalation that fuels every living moment.

Table of Contents

Functions of the respiratory system, main bronchi, the respiratory membrane, respiration, mechanics of breathing, respiratory volumes and capacities, respiratory sounds, external respiration, gas transport, and internal respiration, control of respiration, age-related physiological changes in the respiratory system.

The functions of the respiratory system are:

• Oxygen supplier.  The job of the respiratory system is to keep the body constantly supplied with oxygen.
• Elimination.  Elimination of carbon dioxide.
• Gas exchange.  The respiratory system organs oversee the gas exchanges that occur between the blood and the external environment.
• Passageway.  Passageways that allow air to reach the lungs.
• Humidifier.  Purify, humidify, and warm incoming air.

Anatomy of the Respiratory System

The organs of the respiratory system include the nose, pharynx, larynx, trachea, bronchi, and their smaller branches, and the lungs, which contain the alveoli.

The nose is the only externally visible part of the respiratory system.

• Nostrils.  During breathing, air enters the nose by passing through the nostrils, or nares.
• Nasal cavity. The interior of the nose consists of the nasal cavity, divided by a midline nasal septum .
• Olfactory receptors. The olfactory receptors for the sense of smell are located in the mucosa in the slitlike superior part of the nasal cavity, just beneath the ethmoid bone.
• Respiratory mucosa. The rest of the mucosal lining, the nasal cavity called the respiratory mucosa, rests on a rich network of thin-walled veins that warms the air as it flows past.
• Mucus.  In addition, the sticky mucus produced by the mucosa’s glands moistens the air and traps incoming bacteria and other foreign debris, and lysozyme enzymes in the mucus destroy bacteria chemically.
• Ciliated cells. The ciliated cells of the nasal mucosa create a gentle current that moves the sheet of contaminated mucus posteriorly toward the throat, where it is swallowed and digested by stomach juices.
• Conchae.  The lateral walls of the nasal cavity are uneven owing to three mucosa-covered projections, or lobes called conchae, which greatly increase the surface area of the mucosa exposed to the air, and also increase the air turbulence in the nasal cavity.
• Palate. The nasal cavity is separated from the oral cavity below by a partition, the palate; anteriorly, where the palate is supported by bone, is the hard palate; the unsupported posterior part is the soft palate .
• Paranasal sinuses. The nasal cavity is surrounded by a ring of paranasal sinuses located in the frontal, sphenoid, ethmoid, and maxillary bones ; theses sinuses lighten the skull, and they act as a resonance chamber for speech.

• Size. The pharynx is a muscular passageway about 13 cm (5 inches) long that vaguely resembles a short length of red garden hose.
• Function.  Commonly called the throat , the pharynx serves as a common passageway for food and air.
• Portions of the pharynx. Air enters the superior portion, the nasopharynx , from the nasal cavity and then descends through the oropharynx and laryngopharynx to enter the larynx below.
• Pharyngotympanic tube. The pharyngotympanic tubes, which drain the middle ear open into the nasopharynx.
• Pharyngeal tonsil. The pharyngeal tonsil, often called adenoid is located high in the nasopharynx.
• Palatine tonsils . The palatine tonsils are in the oropharynx at the end of the soft palate.
• Lingual tonsils . The lingual tonsils lie at the base of the tongue.

The larynx or voice box routes air and food into the proper channels and plays a role in speech.

• Structure.  Located inferior to the pharynx, it is formed by eight rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage, the epiglottis .
• Thyroid cartilage. The largest of the hyaline cartilages is the shield-shaped thyroid cartilage, which protrudes anteriorly and is commonly called Adam’s apple .
• Epiglottis.  Sometimes referred to as the “guardian of the airways” , the epiglottis protects the superior opening of the larynx.
• Vocal folds. Part of the mucous membrane of the larynx forms a pair of folds, called the vocal folds, or true vocal cords , which vibrate with expelled air and allows us to speak.
• Glottis.  The slitlike passageway between the vocal folds is the glottis.

• Length.  Air entering the trachea or windpipe from the larynx travels down its length (10 to 12 cm or about 4 inches) to the level of the fifth thoracic vertebra , which is approximately midchest.
• Structure.  The trachea is fairly rigid because its walls are reinforced with C-shaped rings of hyaline cartilage; the open parts of the rings abut the esophagus and allow it to expand anteriorly when we swallow a large piece of food, while the solid portions support the trachea walls and keep it patent, or open, in spite of the pressure changes that occur during breathing.
• Cilia.  The trachea is lined with ciliated mucosa that beat continuously and in a direction opposite to that of the incoming air as they propel mucus, loaded with dust particles and other debris away from the lungs to the throat, where it can be swallowed or spat out.
• Structure.  The right and left main (primary) bronchi are formed by the division of the trachea.
• Location.  Each main bronchus runs obliquely before it plunges into the medial depression of the lung on its own side.
• Size.  The right main bronchus is wider, shorter, and straighter than the left.

• Location.  The lungs occupy the entire thoracic cavity except for the most central area, the mediastinum , which houses the heart, the great blood vessels, bronchi, esophagus, and other organs.
• Apex.  The narrow, superior portion of each lung, the apex, is just deep into the clavicle.
• Base.  The broad lung area resting on the diaphragm is the base.
• Division.  Each lung is divided into lobes by fissures; the left lung has two lobes , and the right lung has three .
• Pleura.  The surface of each lung is covered with a visceral serosa called the pulmonary , or visceral pleura, and the walls of the thoracic cavity are lined by the parietal pleura .
• Pleural fluid. The pleural membranes produce pleural fluid, a slippery serous secretion that allows the lungs to glide easily over the thorax wall during breathing movements and causes the two pleural layers to cling together.
• Pleural space. The lungs are held tightly to the thorax wall, and the pleural space is more of a potential space than an actual one.
• Bronchioles .  The smallest of the conducting passageways are the bronchioles.
• Alveoli.  The terminal bronchioles lead to the respiratory zone structures, even smaller conduits that eventually terminate in alveoli or air sacs.
• Respiratory zone. The respiratory zone, which includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli, is the only site of gas exchange .
• Conducting zone structures. All other respiratory passages are conducting zone structures that serve as conduits to and from the respiratory zone.
• Stroma.  The balance of the lung tissue, its stroma, is mainly elastic connective tissue that allows the lungs to recoil passively as we exhale.
• Wall structure. The walls of the alveoli are composed largely of a single, thin layer of squamous epithelial cells.
• Alveolar pores. Alveolar pores connect neighboring air sacs and provide alternative routes for air to reach alveoli whose feeder bronchioles have been clogged by mucus or otherwise blocked.
• Respiratory membrane. Together, the alveolar and capillary walls, their fused basement membranes, and occasional elastic fibers construct the respiratory membrane (air-blood barrier), which has gas (air) flowing past on one side and blood flowing past on the other.
• Alveolar macrophages. Remarkably efficient alveolar macrophages sometimes called “dust cells” , wander in and out of the alveoli picking up bacteria, carbon particles, and other debris.
• Cuboidal cells. Also scattered amid the epithelial cells that form most of the alveolar walls are chunky cuboidal cells, which produce a lipid (fat) molecule called surfactant , which coats the gas-exposed alveolar surfaces and is very important in lung function.

Physiology of the Respiratory System

The major function of the respiratory system is to supply the body with oxygen and to dispose of carbon dioxide. To do this, at least four distinct events, collectively called respiration, must occur.

• Pulmonary ventilation . Air must move into and out of the lungs so that gasses in the air sacs are continuously refreshed, and this process is commonly called breathing.
• External respiration. Gas exchange between the pulmonary blood and alveoli must take place.
• Respiratory gas transport. Oxygen and carbon dioxide must be transported to and from the lungs and tissue cells of the body via the bloodstream.
• Internal respiration. At systemic capillaries, gas exchanges must be made between the blood and tissue cells.
• Rule.  Volume changes lead to pressure changes, which lead to the flow of gasses to equalize pressure.
• Inspiration.  Air is flowing into the lungs; the chest is expanded laterally, the rib cage is elevated, and the diaphragm is depressed and flattened; lungs are stretched to the larger thoracic volume, causing the intrapulmonary pressure to fall and air to flow into the lungs.
• Expiration.  Air is leaving the lungs; the chest is depressed and the lateral dimension is reduced, the rib cage is descended, and the diaphragm is elevated and dome-shaped; lungs recoil to a smaller volume, intrapulmonary pressure rises, and air flows out of the lung.
• Intrapulmonary volume. Intrapulmonary volume is the volume within the lungs.
• Intrapleural pressure. The normal pressure within the pleural space, the intrapleural pressure, is always negative, and this is the major factor preventing the collapse of the lungs.
• Nonrespiratory air movements. Nonrespiratory movements are a result of reflex activity, but some may be produced voluntarily such as coughing , sneezing, crying, laughing, hiccups, and yawning.

• Tidal volume. Normal quiet breathing moves approximately 500 ml of air into and out of the lungs with each breath.
• Inspiratory reserve volume. The amount of air that can be taken in forcibly over the tidal volume is the inspiratory reserve volume, which is normally between 2100 ml to 3200 ml.
• Expiratory reserve volume. The amount of air that can be forcibly exhaled after a tidal expiration, the expiratory reserve volume, is approximately 1200 ml.
• Residual volume. Even after the most strenuous expiration, about 1200 ml of air still remains in the lungs and it cannot be voluntarily expelled; this is called residual volume, and it is important because it allows gas exchange to go on continuously even between breaths and helps to keep the alveoli inflated.
• Vital capacity. The total amount of exchangeable air is typically around 4800 ml in healthy young men, and this respiratory capacity is the vital capacity, which is the sum of the tidal volume, inspiratory reserve volume, and expiratory reserve volume.
• Dead space volume. Much of the air that enters the respiratory tract remains in the conducting zone passageways and never reaches the alveoli; this is called the dead space volume and during a normal tidal breath, it amounts to about 150 ml.
• Functional volume. The functional volume, which is the air that actually reaches the respiratory zone and contributes to gas exchange, is about 350 ml.
• Spirometer.  Respiratory capacities are measured with a spirometer, wherein as a person breathes, the volumes of air exhaled can be read on an indicator, which shows the changes in air volume inside the apparatus.
• Bronchial sounds. Bronchial sounds are produced by air rushing through the large respiratory passageways (trachea and bronchi).
• Vesicular breathing sounds. Vesicular breathing sounds occur as air fills the alveoli, and they are soft and resemble a muffled breeze.
• External respiration. External respiration or pulmonary gas exchange involves oxygen being loaded and carbon dioxide being unloaded from the blood.
• Internal respiration. In internal respiration or systemic capillary gas exchange, oxygen is unloaded and carbon dioxide is loaded into the blood.
• Gas transport. Oxygen is transported in the blood in two ways: most attaches to hemoglobin molecules inside the RBCs to form oxyhemoglobin, or a very small amount of oxygen is carried dissolved in the plasma; while carbon dioxide is transported in plasma as bicarbonate ion, or a smaller amount (between 20 to 30 percent of the transported carbon dioxide) is carried inside the RBCs bound to hemoglobin.

Neural Regulation

• Phrenic and intercostal nerves. These two nerves regulate the activity of the respiratory muscles, the diaphragm, and external intercostals.
• Medulla and pons. Neural centers that control respiratory rhythm and depth are located mainly in the medulla and pons; the medulla, which sets the basic rhythm of breathing, contains a pacemaker , or self-exciting inspiratory center, and an expiratory center that inhibits the pacemaker in a rhythmic way; pons centers appear to smooth out the basic rhythm of inspiration and expiration set by the medulla.
• Eupnea.  The normal respiratory rate is referred to as eupnea, and it is maintained at a rate of 12 to 15 respirations/minute .
• Hyperpnea.  During exercise, we breathe more vigorously and deeply because the brain centers send more impulses to the respiratory muscles, and this respiratory pattern is called hyperpnea.

Non-neural Factors Influencing Respiratory Rate and Depth

• Physical factors. Although the medulla’s respiratory centers set the basic rhythm of breathing, there is no question that physical factors such as talking, coughing, and exercising can modify both the rate and depth of breathing, as well as an increased body temperature, which increases the rate of breathing.
• Volition (conscious control). Voluntary control of breathing is limited, and the respiratory centers will simply ignore messages from the cortex (our wishes) when the oxygen supply in the blood is getting low or blood pH is falling .
• Emotional factors. Emotional factors also modify the rate and depth of breathing through reflexes initiated by emotional stimuli acting through centers in the hypothalamus .
• Chemical factors. The most important factors that modify respiratory rate and depth are chemical- the levels of carbon dioxide and oxygen in the blood; increased levels of carbon dioxide and decreased blood pH are the most important stimuli leading to an increase in the rate and depth of breathing, while a decrease in oxygen levels become important stimuli when the levels are dangerously low.
• Hyperventilation.  Hyperventilation blows off more carbon dioxide and decreases the amount of carbonic acid, which returns blood pH to the normal range when carbon dioxide or other sources of acids begin to accumulate in the blood.
• Hypoventilation.  Hypoventilation or extremely slow or shallow breathing allows carbon dioxide to accumulate in the blood and brings blood pH back into normal range when blood starts to become slightly alkaline.

Respiratory efficiency is reduced with age. They are unable to compensate for increased oxygen need and are significantly increasing the amount of air inspired. Therefore, difficulty in breathing is usually common especially during activities.  Expiratory muscles become weaker so their cough efficiency is reduced and the amount of air left in the lungs is increased. Health promotion teaching can include smoking cessation, preventing respiratory infections through handwashing , and ensuring up to date influenza and pneumonia vaccinations.

Craving more insights? Dive into these related materials to enhance your study journey!

• Anatomy and Physiology Nursing Test Banks . This nursing test bank includes questions about Anatomy and Physiology and its related concepts such as: structure and functions of the human body, nursing care management of patients with conditions related to the different body systems.

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19.4: Laboratory Activities and Assignment

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• Page ID 53810

• Rosanna Hartline
• West Hills College Lemoore

Laboratory Activities and Assignment

Part 1: review of the respiratory system.

1. Put the following structures in order as indicated by each part a. and b. below:

a. Put the structures in order air passes through from entry into the respiratory system to the point of gas exchange with the blood (this order follows the path of O 2 into the body):

b. Put the structures in order air passes through from gas exchange with the blood to its exit from the respiratory system (this order follows the path of CO 2 out of the body):

2. Label the diagram below with the following structures:

2. Label the diagram of the respiratory mucosa lining much of the large airways of the respiratory tract with the structures listed below.

3. Below is a microscopic image of lung tissue magnified by 100x. Label the following structures:

4. Below is a diagram of alveolar structures with a tissue section showing some of those alveolar structures. Label the following on both the figure and the microscopic tissue section where possible.

Part 2: Examining the Histology of the Respiratory System

• Obtain the slides listed below that are available for today’s lab.
• Focus on each sample and identify the structures listed for each type of tissue.
• Indicate the total magnification you make each illustration at in the space provided.
• Illustrate each tissue you observe with the microscope at the magnification you listed.
• Label each illustration with the structures listed for each.

Trachea Cross Section

Illustrations at more than one magnification will be required.

Label the tissue with: trachea, esophagus, cartilage ring, opening in cartilage ring, lumen, pseudostratified ciliated columnar epithelium, goblet cells, cilia, basement membrane, lamina propria, elastic lamina, mixed glands, hyaline cartilage

Lung Tissue

More than one illustration will required with more than one magnification.

Label the tissue with: secondary bronchi, cartilage plates, pulmonary blood vessels, bronchioles, terminal bronchiole, respiratory bronchiole, alveolar ducts, alveoli, type I alveolar cells, interalveolar septum, endothelium, pulmonary capillary, connective tissue, alveolar lumen

Part 3: Mechanism of Breathing (Balloon-and-Bell Jar Model)

• Balloon-and-bell jar

Instructions & Questions

• Pull down the rubber sheet. What happens to the balloons? ___ .
• This represents the downward movement of the human __ , which causes the chest cavity to become _______ (larger/smaller). This, in turn, causes the human _ _____ to expand and fill with air.
• Release the rubber sheet. What happens to the balloons?______________.
• This represents relaxed __________ (inhaling/exhaling), when the chest cavity becomes smaller and the lungs deflate. Note that this is a passive process.
• What organs do the balloons represent? __________________
• What does the rubber sheet you pulled on represent? ____________________

Attributions

• "Digital Histology" by Department of Anatomy and Neurobiology and the Office of Faculty Affairs , Virginia Commonwealth University School of Medicine and the ALT Lab at Virginia Commonwealth University is licensed under CC BY 4.0
• "Respiratory system complete no labels.svg" by Bibi Saint-Pol, Jmarch is licensed under CC BY-SA 3.0
• "BIOL 250 Human Anatomy Lab Manual SU 19" by Yancy Aquino , Skyline College is licensed under CC BY-NC-SA 4.0
• "Principles of Biology II Lab Manual (BIOL 1108) " by Dalton State is licensed under CC BY-SA 4.0

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Human Respiratory System

What is the human respiratory system.

We all breathe but, have you ever thought about how we breathe? The answer is because of our respiratory system. The respiratory system is the part of your body that helps you breathe. It is an important life-support system of the body that supplies oxygen to the blood and removes waste products such as carbon dioxide. It includes the airways, lungs, and heart , which are all necessary for breathing.

When you are a kid and your respiratory system is working, you don't think much about it. But when something goes wrong with your respiratory system, it can be scary and frustrating. So in this article, we'll talk all about the respiratory system for kids and respiratory system function for kids - so that you're always in the know!

Inhalation and Exhalation

The respiratory system is the chain of organs and tissues that helps living beings breathe properly. It includes the nasal passage, mouth, lungs, and blood vessels . The muscles responsible for the contraction and relaxation of the lungs are also a part of the respiratory system.

Respiratory System

The respiratory system is a biological system in animals and plants that consists of distinct organs and structures required for gas exchange. The respiratory system is a network of organs and tissues that aid in breathing and respiration . The process in which organisms exchange gasses between the body cells and the environment is known as respiration. The process of inhaling oxygen and exhaling carbon dioxide is known as breathing. It consists of your airways, lungs, and blood arteries .

Features of the Human Respiratory System

The structure of the lungs is created in such a way that it helps the exchange of gasses. The other parts of the respiratory system include the nose , larynx , pharynx , trachea or the windpipe, bronchi , lungs, blood vessels, the airways for the passage of air, and the muscles that support the breathing.

All these parts together form the respiratory tract that starts from the external nostrils and nasal chamber and goes up to the lungs. Warms and moisturizes the air to the appropriate humidity level for your body. Your body's cells are supplied with oxygen. When you exhale, you remove waste gasses from your body, including carbon dioxide. Protects dangerous substances and irritants out of your airways.

Respiratory System Parts and Functions

We inhale air through our nose which is the first step in the process of respiration. The nose and nasal cavity are the initial segment of the body's airway—the respiratory tract through which air moves—and are the principal external opening for the respiratory system. The nose is a cartilage , bone, muscle , and skin structure on the face that supports and protects the nasal cavity's anterior section. Before being expelled into the environment, air leaving the body through the nose returns moisture and heat to the nasal cavity.

These are two cartilaginous chords, situated at the joining pointof the pharynx and trachea. They are also called the voice box. The laryngopharynx and the trachea are connected by a brief piece of the airway. The larynx is found in the anterior part of the neck, slightly below the hyoid bone and above the trachea. The form of the larynx is determined by various cartilage components. The larynx has specific structures termed vocal folds, which allow the body to produce speaking and singing sounds in addition to cartilage. Vocal folds are mucous membrane folds that vibrate to make vocal sounds. The pitch produced by the vocal folds can be altered by altering the tension and vibration speed of the vocal folds.

The pharynx is a common path for the passage of both air and food, to their respective organ systems. The pharynx , often known as the throat, is a muscular funnel that runs from the nasal cavity's posterior end to the esophagus and larynx's superior end. The nasopharynx, oropharynx, and laryngopharynx are the three parts of the pharynx. The nasopharynx is the upper part of the pharynx that is located in the back of the nasal cavity. The nasopharynx receives inhaled air from the nasal cavity and transports it to the oropharynx, which is positioned in the back of the oral cavity. At the oropharynx, air inhaled through the mouth cavity enters the pharynx. The epiglottis is a flap of elastic cartilage between the trachea and the esophagus that serves as a switch between the two.

The trachea or the windpipe is like a long tube that takes the inhaled air into the further process. It is divided into left and right bronchi. The trachea, or windpipe, is a 5-inch long tube coated with pseudostratified ciliated columnar epithelium and formed up of C-shaped hyaline cartilage rings. The trachea's primary role is to maintain a free airway for air to enter and exit the lungs. Furthermore, the mucus produced by the epithelium lining the trachea collects dust and other impurities, preventing them from reaching the lungs. Mucus is moved superiorly toward the throat by cilia on the surface of epithelial cells, where it can be eaten and processed in the gastrointestinal system.

Bronchi are further subdivided into small, finer channels called bronchioles. These bronchioles have balloon or bag-like structures at their ends that are known as alveoli. The airway splits into left and right branches at the inferior end of the trachea, known as the main bronchi. Before branching off into smaller secondary bronchi, the left and right bronchi enter each lung. The secondary bronchi—two in the left lung and three in the right lung—carry air into the lobes of the lungs. Within each lobe, the secondary bronchi branches into several smaller tertiary bronchi. The tertiary bronchi are divided into several smaller bronchioles that travel throughout the lungs. Each bronchiole then differentiates into multiple smaller branches, known as terminal bronchioles, with a diameter of less than a millimeter. Finally, the air is carried to the lungs' alveoli by millions of small terminal bronchioles.

Then there are lungs. The inhaled air is purified, and the oxygen necessary for all the body functioning is passed to various organs through the blood vessels. The exchange of oxygen and carbon dioxide takes place in small bags, alveoli. And the impure air of the carbon dioxide is exhaled out of the body through the same tract. The lungs are a pair of big, spongy organs located in the thorax , above the diaphragm, and lateral to the heart. A pleural membrane surrounds each lung, providing space for it to expand as well as a negative pressure area relative to the rest of the body. As the lungs relax, they passively fill with air thanks to the negative pressure.

Respiratory Tract

The respiratory tract of the human respiratory system is a series of organs, starting from the external organs and going up to the internal ones. Each of these organs performs a distinct role in the respiratory system function.

Respiratory System Functions

The respiratory system function is a very important metabolic process in our body that plays a crucial role in all living beings.

Inhalation and Exhalation:

It begins by breathing and ends by exhalation, that’s the simplest explanation. But during and after these two acts, several processes are going on endlessly in our bodies.

Exchange of Gasses Between Lungs and Bloodstream:

The oxygen is exchanged for carbon dioxide and is pumped through the bloodstream. Hundreds of millions of small sacs called alveoli are used to carry out the breathing process. The oxygen inhaled by the alveoli diffuses into the pulmonary capillaries that surround them. It attaches to hemoglobin molecules in red blood cells and then circulates around the body.

Exchange of Gasses Between Bloodstream and Body Tissues

The oxygen-carrying blood releases oxygen into body tissues, through the walls of capillaries. Internal respiration, another important function of the respiratory system, transports oxygen to cells and eliminates waste carbon dioxide. Red blood cells transport oxygen received from the lungs around the body via the vasculature in this respiratory process. When oxygenated blood enters the small capillaries, red blood cells release oxygen. It diffuses into body tissues through capillary walls. Carbon dioxide diffuses from the tissues into red blood cells and plasma in the meantime. Deoxygenated blood carries the carbon dioxide back to the lungs.

The Vibration of the Vocal Cords

The larynx muscles move when we speak, creating sound and vibration. The same process happens during the exhalation also.

Olfaction or Smelling

When we inhale air, the chemicals present in the air activate the receptors of the nervous system on the cilia, and we can identify the smell. The sense of smell, or olfaction, is another particular sense that is affected by chemical stimuli. In the superior nasal cavity, the olfactory receptor neurons are integrated into a small area of the nasal epithelium.

Respiration in Humans

Respiration in humans is divided into two types –

1. The External Respiration

The exchange of gasses between the air in the alveoli and the blood in the capillaries that border the alveolar walls is known as external respiration. The partial pressure of oxygen in the air that enters the lungs from the atmosphere is higher than the partial pressure of carbon dioxide in the blood in the capillaries. The gasses diffuse passively through the simple squamous epithelium lining of the alveoli due to the difference in partial pressures. The passage of oxygen from the air into the blood and carbon dioxide from the blood into the air is the end consequence of external respiration. After then, the oxygen may be carried to the body's tissues, while the carbon dioxide is exhaled and discharged into the atmosphere.

2. Internal Respiration

It involves the exchange of gasses between the blood and cells in the body. Lungs are the largest organ in the respiratory system. The exchange of gasses between the blood in capillaries and the body's tissues is known as internal respiration. Capillary blood has a higher oxygen partial pressure and a lower carbon dioxide partial pressure than the tissues through which it travels. Gasses diffuse through the endothelial lining of capillaries along pressure gradients from high to low pressure due to the difference in partial pressures. The diffusion of oxygen into the tissues and the diffusion of carbon dioxide into the blood are the end results of internal respiration.

Issues Affecting the Respiratory System in Health

It is evident that something is obstructing our ability to exchange carbon dioxide for oxygen. Allergies, asthma , pneumonia, and lung cancer are just a few of the health issues that can cause respiratory problems. Infection (bacterial or viral), environmental exposure (pollution or cigarette smoke, for example), genetic inheritance, or a mix of variables are among the causes of these problems. We don't seek medical help till the problem has progressed because the onset is so slow. Symptoms may appear gradually, as in the case of alpha-1 antitrypsin deficiency (A1AD), and are frequently misunderstood or underdiagnosed. A1AD genetic risk can be detected through DNA health testing.

Diseases of the Lungs and the Respiratory System

Asthma: Your airways are congested, and you're producing an excessive amount of mucus.

Bronchiectasis: Bronchial walls get thicker as a result of inflammation and infection.

COPD (chronic obstructive pulmonary disease): A lung illness that affects millions of people (COPD). Over time, this long-term ailment deteriorates. Bronchitis and emphysema are two of the most common conditions.

Pneumonia: Inflammation of the alveoli is caused by infection. It's possible that they'll become clogged with pus or fluid.

Tuberculosis: This deadly infection is brought on by a bacterium. It most commonly affects your lungs, but it can also impact your kidneys, spine, or brain.

Lung Cancer: Cancer of the lungs A tumour formed when cells in the lungs alter and expand. This is frequently the result of smoking or inhaling other substances.

Cystic Fibrosis: Cystic fibrosis is a disease characterised by the presence of cysts in the lungs This condition develops over time and is caused by a genetic issue. It leads to recurrent lung infections.

Pleural Effusion: Pleural effusion is a condition in which fluid accumulates in the lungs Between the tissues that line your lungs and chest, too much fluid accumulates.

Idiopathic Pulmonary Fibrosis: Idiopathic pulmonary fibrosis is a condition in which the tissue of your lungs gets damaged and unable to function properly.

Sarcoidosis: Granulomas are small clusters of inflamed cells that grow in the lungs and lymph nodes.

Respiratory System Activities for Elementary Students

To attain a healthy breathing system, you must focus on the respiratory system activities for elementary students that involve your respiratory system to work more efficiently than normal. Activities like:

Respiration is a process that involves different organs for breathing. Taking oxygen inside the body is inhalation and the process of releasing carbon dioxide is known as exhalation. The respiratory system involves respiratory organs like the nose, lungs, throat, windpipe and bronchi. Inhalation expands the size of our chest and exhalation contracts the size of our chest. The respiratory system provides us with oxygen. It helps us in talking and smelling. We can keep our respiratory system healthy by doing exercises and yoga. In this article, we have discussed the respiratory system for kids very nicely. But still, if you have any questions ask in the comments.

FAQs on Human Respiratory System

1. Does human respiration take place externally?

No, human respiration is a combined process that involves both internal and external respiration.

2. What is the main function of the respiratory system?

The main function of the respiratory system is to inhale the air, purify it, exchange the gases within the body, and exhale the carbon dioxide.

3. What is the purpose of oxygen in our bodies?

The oxygen is essential for the survival of human beings, and it is required for breaking down of glucose at the cellular level

4. Why is nose an important organ?

The nose is important as it acts as a defensive wall against all the external pathogens that try to enter our bodies.

5. Which part of the brain controls the respiratory system?

The medulla oblongata is the centre of the brain that controls the respiratory system.

6. What is the difference between respiration and breathing?

Respiration and breathing are two different processes and can not be used interchangeably. Breathing takes place in the respiratory organs such as the nose, windpipe, and lungs. Whereas respiration takes place in cells and cell organelles such as mitochondria. It can also be understood in a way that respiration is a chemical reaction whereas breathing is a physical activity.

7. How can respiratory problems be avoided?

Following are the issues that are related to respiration: Pneumonia, Asthma, Tuberculosis, Bronchitis, and Lung cancer. In general, the best way to help prevent the spread of respiratory germs is to avoid contact with droplets or secretions of saliva, mucus and tears. Things that can help include the following: Minimize close contact with persons who have symptoms of respiratory illness, such as coughing or sneezing.

8. What are the respiratory system facts for kids?

Following are the respiratory system facts for kids:

The majority of vertebrate animals (those with spines) have two lungs.

Your left and right lungs are not identical. The lung on the left side of your body has two lobes, while the lung on the right side has three. The left lung is also slightly smaller, giving your heart more room.

The fastest "sneeze speed" ever recorded is 165 km/h.

If the capillaries in the lungs were laid end to end, they would stretch 1,600 kilometres.

Breathing causes us to lose half a litre of water per day. When we breathe onto glass, we observe water vapour.

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Education Specialist I - Human Cellular Therapy Lab

• Rochester, MN
• Laboratory Medicine & Pathology

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Participates in the identification and planning of work unit education . Assists in the development of educational programs for medical trainees (pathologists, residents, fellows, post docs, etc.) as directed by laboratory leadership and Residency and Fellowship Program Directors. Develops, implements and maintains the clinical laboratory education programs for students and interns rotating in the laboratory in compliance with the affiliate program requirements and in collaboration with Mayo Clinic School of Health Sciences and laboratory/Division/Department leadership. Develops, implements and maintains new employee training and education programs in collaboration with laboratory and division leadership to ensure compliance with regulatory and accreditation requirements. Supports the clinical education faculty with formal education programs within the Mayo Clinic School of Health Sciences (MCSHS) as assigned. Teaches, trains and mentors' student and employees., Develops, implements and maintains competency program.

**Individuals hired to this position are required to complete 2 years in this position before becoming eligible to transfer to other positions within Mayo Clinic**

Bachelor's degree in clinical/medical laboratory science (CLS/MLS), medical technology (MT), chemistry, biological science from an accredited institution, or bachelor's degree from an accredited institution in addition to a certificate in MLS. In histopathology or non-testing laboratories, a bachelor's degree with laboratory certification if applicable. Two years of relevant laboratory experience required. A HEW certificate may be substituted for the specified degree. Prior experience in teaching, training and mentoring students and employees is preferred. Strong interpersonal skills including the ability to communicate effectively (written and verbal), strong organizational skills and self-initiative; patience and the ability to effectively coach and mentor others. Experience with data collection, organization, analysis, and delivery of information. Able to work as a team member including taking direction from others. Able to work independently. Able to manage projects. ASCP or other certification pertinent to the laboratory field may be required depending on the laboratory specialty and prevailing regulatory requirements.

Cellular Therapy and/or Flow Cytometry experience preferred, but not required.

**This position is not eligible for visa sponsorship with the exception of the TN visa classification; Also, Mayo Clinic DOES NOT participate in the F-1 STEM OPT extension program**

ALL MUST be included for your application to be considered: •    CV/Resume •    Cover Letter •    Transcripts (unofficial copy accepted) •    Internal candidates must provide their past performance appraisals.

For international/foreign trained applicants, it is the responsibility of the applicant to provide Mayo Clinic the following transcript information in your application: •    MUST have a DETAILED equivalency evaluation            The applicant is responsible for the cost associated with obtaining the equivalency evaluation. •    MUST show US equivalent degree •    Evaluation MUST be completed from an organization listed as a member of the National Association of Credential Evaluation Services (NACES) www.naces.org OR the Association of International Credential Evaluators, Inc. (AICE) www.aice-eval.org

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Rochester, Minnesota

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