Anatomy and Physiology I (BIO 2010)

Correct Answer B. Percussion

Explanation

Chest physiotherapy (CPT) involves percussion techniques, such as clapping or vibrating the chest wall, to help loosen and mobilize mucus in the lungs. This technique is particularly useful for patients with conditions like cystic fibrosis, bronchiectasis, or chronic bronchitis, where mucus clearance is impaired. It is often combined with postural drainage to enhance mucus removal.

Why Other Options Are Wrong

A. Hydration

Proper hydration helps thin mucus, making it easier to clear, but it is not a direct component of chest physiotherapy. Hydration is a supportive measure rather than a technique used in CPT itself.

C. Nebulization

Nebulization delivers medications like bronchodilators or mucolytics to the lungs, but it does not involve mechanical mucus clearance techniques like percussion. It can be used in conjunction with CPT but is not a form of physiotherapy itself.

D. Humidification

Humidification helps prevent airway dryness and maintains mucus mobility, but it does not actively mobilize secretions like percussion does. While it is important in respiratory therapy, it is not considered a component of chest physiotherapy.

Correct Answer B. It prevents food and liquids from entering the airway.

Explanation

The epiglottis is a flap of cartilage that covers the opening of the trachea during swallowing. This prevents food and liquids from entering the airway, reducing the risk of aspiration pneumonia. It plays a critical role in ensuring that the respiratory and digestive systems function separately without interference.

Why Other Options Are Wrong

A. It allows air to pass freely into the trachea.

While the epiglottis opens during breathing to allow air passage, its primary function is to close off the airway during swallowing. Allowing free airflow is important, but this is not its main role in the swallowing process.

C. It aids in the production of sound.

The vocal cords, located in the larynx, are responsible for sound production, not the epiglottis. The epiglottis indirectly affects phonation by modifying airflow but does not directly generate sound.

D. It regulates airflow during breathing.

Airflow is primarily controlled by the trachea, bronchi, and bronchial smooth muscles, not the epiglottis. The epiglottis only temporarily alters airflow during swallowing, not as part of normal respiratory regulation.

Correct Answer C. About 160 mm Hg

Explanation

The partial pressure of oxygen is calculated as 21% of the total atmospheric pressure at sea level (760 mm Hg). By multiplying 0.21 by 760 mm Hg, the partial pressure of oxygen is found to be approximately 160 mm Hg. This value represents the portion of atmospheric pressure contributed by oxygen.

Why Other Options Are Wrong

A. About 25 mm Hg

This value is significantly lower than the actual partial pressure of oxygen. A partial pressure this low would indicate an atmosphere with far less oxygen than normal Earth conditions.

B. About 80 mm Hg

This value is roughly half of the correct value. The calculation (0.21 * 760 mm Hg) results in a much higher partial pressure of oxygen. Such a low oxygen level is more typical of high-altitude conditions, not sea level.

D. About 240 mm Hg

This is an overestimation of the partial pressure of oxygen. Oxygen comprises only 21% of the atmospheric pressure, not a third. If the partial pressure were this high, total atmospheric pressure would have to be significantly greater than 760 mm Hg.

E. About 760 mm Hg

This represents the total atmospheric pressure at sea level, not just the oxygen component. Oxygen is only a fraction of the atmosphere, making this option incorrect.

Correct Answer B. Empyema contains infected fluid.

Explanation

Empyema is a collection of pus in the pleural cavity, usually caused by bacterial infections such as pneumonia. Unlike non-infectious pleural effusion, empyema contains infected fluid, white blood cells, and inflammatory debris, requiring antibiotics and drainage for treatment. If left untreated, it can lead to fibrosis and restricted lung expansion.

Why Other Options Are Wrong

A.Empyema is always associated with pneumonia.

Empyema is not always associated with pneumonia, although pneumonia is a common cause. Other infections, such as tuberculosis or post-surgical complications, can also lead to empyema. It is not exclusive to pneumonia-related infections.

C. Empyema occurs only in children.

Empyema does not occur only in children; it can affect individuals of all ages. While children can develop empyema due to respiratory infections, adults, especially those with weakened immune systems or post-surgical infections, are also at risk.

D. Empyema is a type of lung cancer.

Empyema is not a type of lung cancer; it is an infection-related condition. Lung cancer can cause pleural effusion but does not result in empyema unless a secondary infection occurs. Empyema is treated with antibiotics and drainage rather than cancer therapies.

Correct Answer B. The epiglottis may not close properly, increasing the risk of aspiration into the lungs

Explanation

The epiglottis acts as a protective structure that prevents food and liquids from entering the airway during swallowing. If it fails to close properly, substances can enter the trachea and lungs, leading to aspiration pneumonia or choking.

Why Other Options Are Wrong

A. The epiglottis may become inflamed, leading to increased airflow

While inflammation can affect the epiglottis, it does not lead to increased airflow. Inflammation can actually obstruct the airway and make breathing more difficult.

C. The epiglottis will enhance the swallowing reflex, improving airway protection

If the epiglottis is not functioning properly, it does not enhance the swallowing reflex. Instead, it compromises airway protection, increasing the risk of aspiration.

D. The epiglottis will have no effect on respiratory health in this scenario

An improperly functioning epiglottis can have serious consequences for respiratory health, including aspiration pneumonia, airway obstruction, and breathing difficulties.

Correct Answer A. Increased risk of airway obstruction due to mucus buildup.

Explanation

In chronic bronchitis, excess mucus production leads to airway obstruction and a persistent cough, which serves as a mechanism to clear mucus. Suppressing the cough reflex prevents mucus clearance, increasing the risk of airway blockage, infections, and respiratory complications. This can worsen breathing difficulties and contribute to bacterial colonization in stagnant mucus.

Why Other Options Are Wrong

B. Improved lung function due to reduced irritation.

Suppressing the cough may reduce symptoms temporarily, but it does not improve lung function. Instead, mucus accumulates in the airways, worsening airflow obstruction. Over time, the retained secretions can increase inflammation, leading to further deterioration of lung function.

C. Decreased likelihood of respiratory infections.

Retaining mucus actually increases the risk of infections because bacteria and viruses can thrive in mucus-filled airways. Infections such as pneumonia and bacterial bronchitis are more likely when mucus clearance is impaired.

D. Enhanced effectiveness of mucolytic agents.

Mucolytic agents help thin mucus, but their effectiveness depends on an active cough reflex to expel loosened secretions. If the cough reflex is suppressed, even thinner mucus may accumulate and contribute to obstruction rather than improving airway clearance.

Correct Answer B. To line the thoracic cavity.

Explanation

The parietal pleura is the outer layer of the pleural membrane and lines the inner surface of the thoracic cavity. It helps maintain negative pressure within the pleural space, allowing smooth lung expansion and contraction during breathing.

Why Other Options Are Wrong

A. To cover the lungs directly.

The visceral pleura, not the parietal pleura, covers the lungs directly. The visceral pleura and parietal pleura together create the pleural cavity, which helps facilitate lung movement.

C. To facilitate gas exchange.

Gas exchange occurs in the alveoli, not within the pleural membranes. The pleura do not play a direct role in oxygen and carbon dioxide diffusion.

D. To produce surfactant.

Surfactant is produced by type II alveolar cells within the lungs, not the pleural membranes. Surfactant reduces alveolar surface tension to prevent lung collapse, whereas the pleura primarily functions in lung movement and protection.

Correct Answer C. Glucagon

Explanation

Glucagon is released by the pancreas in response to fasting to increase blood glucose levels. It promotes glycogen breakdown and glucose production to maintain energy availability during periods without food intake. This hormone ensures that blood sugar remains stable when dietary glucose is unavailable.

Why Other Options Are Wrong

A. Insulin is secreted when blood glucose levels are high, such as after a meal, not during fasting. During fasting, insulin levels drop to prevent excess glucose uptake, allowing glucagon to take over and stimulate glucose release. High insulin levels during fasting would lead to hypoglycemia.

B. Prolactin is involved in lactation and reproductive functions rather than metabolic regulation during fasting. Its secretion does not increase significantly in response to changes in blood glucose levels. Unlike glucagon, prolactin does not play a role in mobilizing energy stores.

D. Melatonin regulates sleep-wake cycles but does not influence glucose metabolism. While melatonin levels rise at night to promote sleep, they are not directly linked to fasting or blood sugar regulation. Energy mobilization during fasting is controlled by glucagon, not melatonin.

Correct Answer C. Oxytocin

Explanation

Oxytocin is produced by the hypothalamus and stored in the posterior pituitary, from where it is released. It plays a crucial role in uterine contractions during childbirth and milk ejection during breastfeeding. Unlike the other hormones listed, oxytocin is not synthesized in the anterior pituitary.

Why Other Options Are Wrong

A. TSH (Thyroid-Stimulating Hormone)

TSH is secreted by the anterior pituitary and regulates the thyroid gland’s production of T3 and T4, which are essential for metabolism. It is a key hormone in the hypothalamic-pituitary-thyroid axis.

B. Growth Hormone (GH)

GH is produced by the anterior pituitary and stimulates growth, cell regeneration, and metabolism. It affects multiple organs, including muscles, bones, and the liver, where it promotes IGF-1 production.

D. FSH (Follicle-Stimulating Hormone)

FSH is secreted by the anterior pituitary and regulates reproductive functions in both males and females. It stimulates spermatogenesis in men and follicular development in women, playing a key role in fertility.