Module 2 - Respiratory system

Question 1

Where is the hilum of the lung located?

Answer 1

The hilum of the lung is located on the medial surface

Question 2

What is the primary function of alveolar pneumocytes?

Answer 2

Alveolar pneumocytes facilitate gas exchange in the lungs by promoting the diffusion of oxygen into the bloodstream and the removal of carbon dioxide from the bloodstream.

Question 3

What happens to the oxygen-haemoglobin dissociation curve upon increased metabolic demand, such as during exercise?

Answer 3

The curve would shift to the right, causing more oxygen to be unloaded for a given plasma PO2.

Question 4

True or False: Sympathetic stimulation of the lungs causes a dilation of the bronchioles.

Answer 4

True. Sympathetic stimulation of the lungs causes the bronchioles to dilate or relax, which can increase airflow.

Question 5

True or False: An increase in the partial pressure of carbon dioxide in plasma would shift the curve to the right, causing more oxygen to be unloaded from hemoglobin

Answer 5

True. This statement accurately describes the Bohr effect, where increased carbon dioxide levels or decreased pH (caused by higher carbon dioxide levels) lead to increased oxygen unloading from hemoglobin, facilitating oxygen release to tissues.

Question 6

How does the muscular system integrate with respiration?

Answer 6

The muscular system plays a crucial role in respiration by controlling the expansion and contraction of the diaphragm and intercostal muscles, which are essential for the inhalation and exhalation of air.

Question 7

What are the key anatomical structures of the upper respiratory system?

Answer 7

The nose, pharynx, and associated structures

Question 8

What are the key anatomical structures of the lower respiratory system?

Answer 8

The lower respiratory system consists of the
larynx, trachea, bronchi, and lungs

Question 9

Describe Boyle’s Law and its relationship to respiration.

Answer 9

As the lungs expands, the volume inside the lungs increases and the pressure inside decreases (it follows Boyle’s law). As the pressure is in lower concentration inside the body, the air moves inside the lungs from outsides.

Question 10

What is the process of respiration, and why are pressure gradients important in this process?

Answer 10

Respiration is the exchange of oxygen and carbon dioxide between the lungs and the bloodstream.

Pressure gradients are essential because they drive the movement of gases.
Oxygen moves from areas of high partial pressure (in the lungs) to areas of lower partial pressure (in the bloodstream), while carbon dioxide moves in the opposite direction.

Question 11

What are the main factors that influence respiration?

Answer 11

The main factors influencing respiration include partial pressures of gases (oxygen and carbon dioxide), lung compliance, airway resistance, and neural control mechanisms (such as the respiratory centers in the brainstem). Additionally, factors like altitude, temperature, and physical activity can also affect respiration.

Question 12

What are the main factors that influence respiration?

Answer 12

The main factors influencing respiration include partial pressures of gases (oxygen and carbon dioxide), lung compliance, airway resistance, neural control mechanisms, and environmental factors like altitude and physical activity.

Question 13

Describe the anatomy of the alveoli and the functional differences between the types of alveolar cells.

Answer 13

Alveoli are small air sacs in the lungs where gas exchange occurs. They contain two types of cells: Type I alveolar cells, which are thin and responsible for gas exchange, and Type II alveolar cells, which produce surfactant to reduce surface tension.

Question 14

Describe the Law of LaPlace and Fick’s Law and how they relate to the alveoli.

Answer 14

The Law of LaPlace describes the relationship between pressure, radius, and surface tension in small alveoli, explaining that smaller alveoli require greater pressure to stay open. Fick’s Law relates to gas diffusion and states that the rate of gas diffusion is directly proportional to the surface area, partial pressure gradient, and inversely proportional to the thickness of the respiratory membrane.

Question 15

Describe the function of surfactant and how ventilation would be affected without it.

Answer 15

Surfactant is a substance produced by Type II alveolar cells that reduces surface tension in the alveoli. Without surfactant, alveoli would collapse and require significantly more effort to inflate during each breath, making ventilation much more difficult.

Question 16

Describe Dalton’s and Henry’s law and how they contribute to gas exchange.

Answer 16

Dalton’s Law states that in a mixture of gases, each gas exerts its own partial pressure independently. Henry’s Law explains how gases dissolve in liquids, stating that the amount of gas dissolved in a liquid is directly proportional to its partial pressure and solubility in that liquid. These laws contribute to gas exchange by governing the movement of gases between the alveoli and the bloodstream.

Question 17

Describe ventilation and perfusion coupling.

Answer 17

Ventilation and perfusion coupling refers to the matching of airflow (ventilation) and blood flow (perfusion) in the lungs. It ensures that oxygen is delivered to well-ventilated alveoli and that carbon dioxide is removed efficiently, optimizing gas exchange.

Question 18

Describe the transport of gases in the body and what influences this.

Answer 18

Gases like oxygen and carbon dioxide are transported in the body primarily through the bloodstream. Hemoglobin in red blood cells carries oxygen, while dissolved carbon dioxide forms bicarbonate ions. Factors influencing gas transport include partial pressures, temperature, pH, and the affinity of hemoglobin for oxygen and carbon dioxide.

Question 19

Describe the autonomic nervous system (ANS).

Answer 19

The autonomic nervous system (ANS) is a division of the nervous system responsible for involuntary functions. It consists of the sympathetic and parasympathetic branches, which often have opposing effects on bodily functions.

Question 20

Name the central (brain) regions of respiratory regulation.

Answer 20

The central regions of respiratory regulation include the medulla oblongata and the pons, which are located in the brainstem.

Question 21

Describe the afferent inputs to the medulla oblongata.

Answer 21

Afferent inputs to the medulla oblongata involved in respiratory regulation include sensory information from peripheral chemoreceptors (e.g., carotid and aortic bodies) and central chemoreceptors (e.g., in the medulla itself). These receptors monitor factors like oxygen and carbon dioxide levels in the blood.

Question 22

Describe the efferent response to these inputs.

Answer 22

In response to afferent inputs, the medulla oblongata regulates respiration by adjusting the rate and depth of breathing. It sends efferent signals to the diaphragm and intercostal muscles to control inspiration and expiration.

Question 23

Apply the knowledge of automatic nervous system regulation of respiration to the exercise scenario.

Answer 23

During exercise, the sympathetic branch of the ANS becomes more active. This leads to an increase in respiratory rate and depth to meet the increased oxygen demand of active muscles.

Question 24

Explain Obstructive Sleep Apnea (OSA)

Answer 24

OSA is a sleep-related breathing disorder characterized by repeated episodes of partial or complete obstruction of the upper airway during sleep.

Individuals with OSA often experience loud snoring, gasping, or choking during sleep, which can lead to fragmented and poor-quality sleep.

Risk factors for OSA include obesity, a narrowed airway, and family history.

Treatment options may include lifestyle changes, such as weight loss, the use of continuous positive airway pressure (CPAP) devices, or surgery to remove obstructions.

Question 25

Explain Cystic Fibrosis

Answer 25

Cystic fibrosis is a genetic disorder that affects the respiratory and digestive systems, primarily due to mutations in the CFTR gene.

The disease results in the production of thick and sticky mucus, which clogs the airways, making it difficult to breathe and increasing the risk of lung infections.

Symptoms include chronic cough, wheezing, recurrent lung infections, and poor growth in children.

Treatment aims to manage symptoms and includes chest physiotherapy, medications to thin mucus, and antibiotics to treat infections.

Question 26

Explain Asthma

Answer 26

Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, leading to symptoms such as wheezing, coughing, shortness of breath, and chest tightness.

Triggers for asthma attacks can include allergens, respiratory infections, exercise, and environmental factors.

Asthma symptoms can range from mild to severe, with asthma exacerbations requiring immediate medical attention.

Treatment includes long-term control medications (e.g., inhaled corticosteroids) to manage inflammation and rescue inhalers (e.g., bronchodilators) for quick relief during attacks.

Question 27

Explain Obstructive and Restrictive Pulmonary Diseases

Answer 27

Obstructive pulmonary diseases, such as chronic obstructive pulmonary disease (COPD) and asthma, involve a limitation of airflow due to narrowed or obstructed airways.

Restrictive pulmonary diseases, like interstitial lung diseases and pulmonary fibrosis, involve a restriction in lung expansion and reduced lung volume.

Common symptoms of obstructive diseases include coughing, wheezing, and difficulty exhaling, while restrictive diseases are characterized by shortness of breath and reduced lung capacity.

Obstructive diseases often result from chronic exposure to irritants (e.g., smoking in COPD), while restrictive diseases may be caused by factors like lung tissue scarring or inflammation.

Treatment for these conditions varies but may include medications, pulmonary rehabilitation, oxygen therapy, and in some cases, lung transplantation.