enlargement of the thyroid commonly known as a goiter might be expected to affect

HESI A2

HESI A2 Anatomy and Physiology Practice Test

1. Enlargement of the thyroid, commonly known as a goiter, might be expected to affect ___________.

A. swallowing
B. insulin levels
C. sleep
D. digestion

Correct answer: A

Rationale: Enlargement of the thyroid, known as a goiter, can compress the nearby structures in the neck, including the esophagus. This compression can lead to symptoms such as difficulty swallowing (dysphagia) or a sensation of pressure in the throat. Therefore, an enlarged thyroid gland is expected to affect swallowing. Choices B, C, and D are incorrect because a goiter primarily affects structures in the neck due to its physical enlargement, rather than directly impacting insulin levels, sleep, or digestion.

2. Which hormone is released by the adrenal glands during stress?

A. Insulin
B. Adrenaline
C. Melatonin
D. Cortisol

Correct answer: B

Rationale: Adrenaline, also known as epinephrine, is released by the adrenal glands during stress to prepare the body for rapid action. It helps in triggering the body's fight-or-flight response, increasing heart rate, and providing a burst of energy when faced with stressful situations. Insulin (Choice A) is produced by the pancreas to regulate blood sugar levels, not by the adrenal glands. Melatonin (Choice C) is a hormone that regulates sleep-wake cycles and is produced by the pineal gland, not the adrenal glands. Cortisol (Choice D) is another hormone produced by the adrenal glands, but it is not the primary hormone released during immediate stress responses; it is more involved in long-term stress regulation.

3. Which type of muscle tissue is found in the heart?

A. Smooth muscle
B. Cardiac muscle
C. Skeletal muscle
D. Striated muscle

Correct answer: B

Rationale: Cardiac muscle tissue, represented by choice B, is the correct answer. Cardiac muscle tissue is unique to the heart and responsible for its involuntary contractions that pump blood throughout the body. Smooth muscle (choice A) is found in the walls of hollow organs, skeletal muscle (choice C) is attached to bones for movement, and striated muscle (choice D) is a general term that can refer to both cardiac and skeletal muscle but is not specific to the heart.

4. Which hormone stimulates milk production in the breasts during lactation?

A. norepinephrine
B. antidiuretic hormone
C. prolactin
D. oxytocin

Correct answer: C

Rationale: During lactation, the hormone responsible for stimulating milk production in the breasts is 'prolactin.' Prolactin plays a crucial role in initiating and maintaining lactation by promoting the development of alveoli in the mammary glands and stimulating milk synthesis. While oxytocin is involved in the ejection of milk from the breasts, it is prolactin that primarily governs milk production. Norepinephrine is not directly involved in milk production, and antidiuretic hormone primarily regulates water balance and blood pressure, not milk production.

5. What is the normal pH of human arterial blood?

A. 6.8
B. 7.4
C. 7.9
D. 8.2

Correct answer: B

Rationale: The normal pH of human arterial blood is approximately 7.4. This slightly alkaline pH is crucial for the proper functioning of enzymes and biochemical processes in the body. Any significant deviation from this pH level can result in serious health issues such as acidosis or alkalosis. Choice A (6.8) is incorrect as it is lower than the normal pH of arterial blood, indicating acidity. Choice C (7.9) and Choice D (8.2) are incorrect as they are higher than the normal pH of arterial blood, indicating alkalinity.