1. During gas exchange in the alveoli, what happens to oxygen?

A. Oxygen is released from the bloodstream into the alveoli.
B. Oxygen is absorbed from the alveoli into the bloodstream.
C. Oxygen is converted into carbon dioxide.
D. Oxygen is stored in the alveoli for later use.

Correct answer: B

Rationale: During gas exchange in the alveoli, oxygen is absorbed from the alveoli into the bloodstream. In the alveoli, oxygen diffuses across the thin walls of the alveoli and into the surrounding capillaries where it binds to hemoglobin in red blood cells. This oxygen-rich blood is then transported to the body's tissues for cellular respiration. Therefore, option B is correct as it accurately describes the direction of oxygen movement during the process of gas exchange in the lungs.

2. Which of the following is a unit of power?

A. Newton-meter (NÃ‚Â·m)
B. Joule (J)
C. Watt (W)
D. Kilogram (kg)

Correct answer: c

Rationale: Watt is the unit of power, measuring the rate of work done or energy transfer.

3. Which of the following is NOT a major division of the nervous system?

A. Peripheral nervous system
B. Central nervous system
C. Somatic nervous system
D. Autonomic nervous system

Correct answer: C

Rationale: The somatic nervous system is actually a component of the peripheral nervous system, responsible for voluntary control of skeletal muscles and sensory information. The major divisions of the nervous system are the central nervous system (which includes the brain and spinal cord) and the peripheral nervous system (which includes all nerves outside the central nervous system). The autonomic nervous system, on the other hand, is a division of the peripheral nervous system responsible for involuntary functions like heart rate and digestion. Therefore, the correct answer is C, the somatic nervous system, as it is not a major division of the nervous system.

4. A condition characterized by an overactive thyroid gland and excessive production of thyroid hormones is called:

A. Diabetes mellitus
B. Hyperthyroidism
C. Hypothyroidism
D. Cushing's syndrome

Correct answer: B

Rationale: The correct answer is B: Hyperthyroidism. Hyperthyroidism is a condition where the thyroid gland becomes overactive and produces an excess of thyroid hormones. This can lead to symptoms such as weight loss, rapid heart rate, and anxiety. Diabetes mellitus (A) is a condition characterized by high blood sugar levels. Hypothyroidism (C) is the opposite of hyperthyroidism, where the thyroid gland is underactive. Cushing's syndrome (D) is a disorder caused by prolonged exposure to high levels of the hormone cortisol. Therefore, in this case, the correct answer is B as it specifically relates to an overactive thyroid gland.

5. During inhalation, which muscle contracts to increase the volume of the thoracic cavity, allowing air to flow into the lungs?

A. Diaphragm
B. Intercostal muscles
C. Abdominal muscles
D. Pectoral muscles

Correct answer: A

Rationale: The correct answer is A: Diaphragm. During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity. This action creates a pressure difference between the lungs and the atmosphere, causing air to flow into the lungs. The intercostal muscles also play a role by expanding the ribcage, but the primary muscle responsible for increasing thoracic cavity volume during inhalation is the diaphragm. Abdominal muscles are involved in exhalation by contracting to push the diaphragm up, reducing thoracic cavity volume. Pectoral muscles are located in the chest and are not directly involved in the breathing process.