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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 mm 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 ( [link] ). 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.

Normal and bronchial asthma tissues

The top panel of this figure shows normal lung tissue, and the bottom panel shows lung tissue inflamed by asthma.
(a) Normal lung tissue does not have the characteristics of lung tissue during (b) an asthma attack, which include thickened mucosa, increased mucus-producing goblet cells, and eosinophil infiltrates.

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?

Chapter review

The respiratory system is responsible for obtaining oxygen and getting rid of carbon dioxide, and aiding in speech production and in sensing odors. From a functional perspective, the respiratory system can be divided into two major areas: the conducting zone and the respiratory zone. The conducting zone consists of all of the structures that provide passageways for air to travel into and out of the lungs: the nasal cavity, pharynx, trachea, bronchi, and most bronchioles. The nasal passages contain the conchae and meatuses that expand the surface area of the cavity, which helps to warm and humidify incoming air, while removing debris and pathogens. The pharynx is composed of three major sections: the nasopharynx, which is continuous with the nasal cavity; the oropharynx, which borders the nasopharynx and the oral cavity; and the laryngopharynx, which borders the oropharynx, trachea, and esophagus. The respiratory zone includes the structures of the lung that are directly involved in gas exchange: the terminal bronchioles and alveoli.

The lining of the conducting zone is composed mostly of pseudostratified ciliated columnar epithelium with goblet cells. The mucus traps pathogens and debris, whereas beating cilia move the mucus superiorly toward the throat, where it is swallowed. As the bronchioles become smaller and smaller, and nearer the alveoli, the epithelium thins and is simple squamous epithelium in the alveoli. The endothelium of the surrounding capillaries, together with the alveolar epithelium, forms the respiratory membrane. This is a blood-air barrier through which gas exchange occurs by simple diffusion.

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?

Inflammation and the production of a thick mucus; constriction of the airway muscles, or bronchospasm; and an increased sensitivity to allergens.

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References

Bizzintino J, Lee WM, Laing IA, Vang F, Pappas T, Zhang G, Martin AC, Khoo SK, Cox DW, Geelhoed GC, et al. Association between human rhinovirus C and severity of acute asthma in children. Eur Respir J [Internet]. 2010 [cited 2013 Mar 22]; 37(5):1037–1042. Available from: (External Link)&gca=erj%3B37%2F5%2F1037&allch=

Kumar V, Ramzi S, Robbins SL. Robbins Basic Pathology. 7th ed. Philadelphia (PA): Elsevier Ltd; 2005.

Martin RJ, Kraft M, Chu HW, Berns, EA, Cassell GH. A link between chronic asthma and chronic infection. J Allergy Clin Immunol [Internet]. 2001 [cited 2013 Mar 22]; 107(4):595-601. Available from: (External Link)&gca=erj%3B37%2F5%2F1037&allch=

Questions & Answers

musah was admitted to your ward yesterday with traumatic amputation of the right thump . he complained this morning that he has not passed enough urine. Questions. 1) will you consider his complain to be pathological or physiological?. 2) in less than three sentences, justify your opinion. 3) Apply your understanding of the renin- angiotensin-aldosterone system to explain the factors and mechanisms accounting for his complains.
Ellen Reply
the mineral salt which break up a large portion of bone tissue is
Aurora Reply
calcium
Calcium
Sawda
cholesterol and triglycerides in simplest terms are fats (lipid) found in blood
Roy Reply
calcium is important for bone density and development. it also helps for safe / normal blood clotting, blood circulation to and from the heart, and muscle movement
Roy
what is muscle tissue
Rifat Reply
the muscle tissue is one of the 4 basic tissues in our body and is responsible for movement of our body
What Is difference between Ovary and Ovum
Sawda
ovary is female reproductive organ while ovum is a female gamete formed from ovary
Ubaidah
Thank You
Sawda
What Is Cholesterol and Triglycerides
Sawda
the mineral salt which break up a large portion of bone tissue
Aurora
Hi Be Home Be safe , how are things doing hope all is well
Natarajan Reply
3 longitudinal bands of smooth muscles found in large intestines
Jamia
what's is sutures
Nimeshka Reply
what would I like to know
Roy Reply
anything u can tell me
Roy
anatomy mins
Manish
when two or more bones meet.
Joseph
Joints
Anita
I am interested in learning but it is a little threatening corona virus covid 19
Samnang Reply
I don't know about Corona virus
Vicky
what would you like to know?
Mbasa
what is a peripheral protien
Ayesha Reply
actually its located in between the lipid layer, it does not specify if it's closer to the inside or the outside of the cell
Justin
It is protein found in lipid bilayer but found attached with Cytoplasm aspect
Jamal
what are the collection of blood.?
sunshine Reply
Effect of exercise on different body systems?
Rania Reply
what is ambroylogy
kashif Reply
embryology..is the biological studing of embryos
Ava
I know biological study but embryology mean any pic, example?
kashif
https://upload.wikimedia.org/wikipedia/commons/b/b6/Comparative_embryology_of_the_vertebrates%3B_with_2057_drawings_and_photos._grouped_as_380_illus_%281953%29_%2820482505100%29.jpg
Ava
I like to learn about medical and more
Samnang
what is the function of the blood
Yolanda Reply
Transporting of oxygen,fighting against germs, forms clotting ,distribution of nutrients and minerals through out the body ,
Nimco
Transportation of gases such as oxygen and water blance and carrei metabolites to the exit organ and Acid base equilibrium and clotting blood and Immune
Jamal
What are Gross and microscopicAnatomy
Waiswa Reply
study of the internal structures of a human being
Niyi
gross anatomy is the study of body parts that can be seen with our naked eyes while micro anatomy involves the study of body parts that cannot be seen with our naked eyes but with the aid of a microscope
Oppong
gross means examination of specimen or tissue with bare (unaided ) eye while microscopic means examination of same with the help of microscope
Jamia
what is physiology
Waiswa Reply
what are blood pressure
Waiswa
physiology is the study of the normal functions of organs
Romaissaa
Blood pressure is a when systolic phase is 190 and diastolic phase 90.
Rahma
systolic phase is 180.not 190
Manish

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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