Which type of muscle is under voluntary control?
- A. Smooth muscle
- B. Cardiac muscle
- C. Skeletal muscle
- D. Involuntary muscle
Correct Answer: C
Rationale: The correct answer is C: Skeletal muscle. Skeletal muscle is under voluntary control, allowing for conscious movement of the body. Smooth muscle and cardiac muscle are both types of involuntary muscles that are not under conscious control. Smooth muscle is found in the walls of internal organs and blood vessels, functioning involuntarily. Cardiac muscle makes up the heart and contracts involuntarily to pump blood. Involuntary muscle (choice D) is a general term that encompasses smooth muscle and cardiac muscle, which operate involuntarily throughout the body.
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Which of the following statements is not true about the relationship between the gastrointestinal system and the endocrine system?
- A. Hormones signal to your body whether you are hungry or full.
- B. Hormones regulate the amount of glucose in your blood.
- C. Hormones stimulate digestive enzymes and peristalsis when you've eaten and need to digest food.
- D. All of the above are true.
Correct Answer: D
Rationale: The gastrointestinal system and the endocrine system are closely interconnected. Hormones released by the endocrine system play a crucial role in signaling hunger or fullness, regulating blood glucose levels, and stimulating digestive processes like enzyme secretion and peristalsis for efficient food digestion. Option D, stating 'All of the above are true,' is incorrect in the context of the question because there is a need to identify the statement that is not true about the relationship between the gastrointestinal system and the endocrine system. Choices A, B, and C are all correct statements that reflect the close relationship and interactions between the gastrointestinal and endocrine systems.
How many lobes does the right lung have?
- A. 1
- B. 2
- C. 3
- D. 4
Correct Answer: C
Rationale: The correct answer is C: 3. The right lung consists of three lobes: the upper, middle, and lower lobes. This distinction is vital as the left lung only has two lobes, the upper and lower lobes. Understanding the anatomical variances between the lobes of the right and left lungs is crucial for comprehending respiratory physiology and its clinical implications in medical practice. Choices A, B, and D are incorrect because the right lung does not have 1, 2, or 4 lobes. It is essential to differentiate between the lobes of the right and left lungs to have a comprehensive understanding of pulmonary anatomy.
What is the function of the endocrine system?
- A. To protect the body from infection
- B. To release digestive enzymes
- C. To break down food
- D. To regulate the sleep-wake cycle
Correct Answer: B
Rationale: The correct answer is B. The endocrine system releases hormones that regulate various functions, including metabolism and growth. It is responsible for producing and releasing hormones that control processes such as metabolism, growth, and development. The digestive enzymes are released by the digestive system, not the endocrine system. Choices A, C, and D are incorrect because protecting the body from infection is primarily the role of the immune system, breaking down food is the function of the digestive system, and regulating the sleep-wake cycle is controlled by the circadian rhythm which is mainly influenced by the brain's hypothalamus and not the endocrine system.
What is the most powerful stimulus for breathing in a healthy person?
- A. Acidosis
- B. Alkalosis
- C. Increase in CO2
- D. Loss of O2
Correct Answer: C
Rationale: The correct answer is an increase in CO2. In a healthy individual, the primary drive to breathe is regulated by the levels of carbon dioxide (CO2) in the blood. When CO2 levels increase, it triggers the body to increase the rate and depth of breathing to eliminate excess CO2 and restore the balance. This response is more powerful than other stimuli such as acidosis, alkalosis, or loss of oxygen. While acidosis and alkalosis can affect breathing, an increase in CO2 has a more direct and immediate impact. Loss of oxygen (hypoxia) is a potent stimulus, but the body's response to increased CO2 levels is generally more pronounced and immediate in healthy individuals.
Which type of blood cell is primarily responsible for fighting infections?
- A. Red blood cell
- B. White blood cell
- C. Platelet
- D. Plasma
Correct Answer: B
Rationale: The correct answer is B: White blood cell. White blood cells are the primary cells responsible for fighting infections and foreign invaders in the body. Red blood cells carry oxygen to tissues, platelets help in blood clotting to prevent excessive bleeding, and plasma is the liquid component of blood that carries cells and nutrients. White blood cells, also known as leukocytes, play a crucial role in the immune system by identifying and destroying pathogens, such as bacteria, viruses, and other harmful substances. Therefore, they are the key players in the body's defense against infections, making them the correct answer in this scenario. While red blood cells, platelets, and plasma have essential functions in the body, they are not primarily responsible for combating infections like white blood cells.