which type of muscle is found in the walls of hollow organs

HESI A2

HESI A2 Practice Test Anatomy and Physiology

1. Which type of muscle is found in the walls of hollow organs?

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

Correct answer: C

Rationale: Smooth muscle tissue is found in the walls of hollow organs, such as the intestines, blood vessels, and bladder. It contracts involuntarily, allowing for movements like peristalsis in the intestines and regulation of blood flow in blood vessels. Skeletal muscle (Choice A) is attached to bones and helps in voluntary movements. Cardiac muscle (Choice B) is found in the heart and contracts involuntarily to pump blood. Striated muscle (Choice D) refers to both skeletal and cardiac muscles, which have a striped appearance due to the organization of their filaments. However, smooth muscle (Choice C) is specifically the type found in hollow organs.

2. How might the headrest on a car prevent traumatic injury?

A. By limiting hyperflexion of the neck
B. By limiting hyperextension of the neck
C. By reducing vertebral compression
D. By preventing disc degeneration

Correct answer: B

Rationale: The headrest on a car is designed to prevent traumatic injury by limiting hyperextension of the neck during a rear-end collision. This helps reduce the risk of whiplash and other neck injuries that may occur when the head is forcefully thrown backward. Choice A is incorrect because hyperflexion is not the primary concern in rear-end collisions. Choice C is incorrect as the headrest does not directly reduce vertebral compression. Choice D is incorrect because the headrest is not directly involved in preventing disc degeneration.

3. Which vitamin is essential for the absorption of calcium?

A. Vitamin A
B. Vitamin D
C. Vitamin K
D. Vitamin C

Correct answer: B

Rationale: Vitamin D is crucial for the absorption of calcium in the intestines, which is vital for maintaining strong bones and teeth. It helps regulate calcium levels in the blood and promotes bone mineralization, making it an essential vitamin for overall bone health. Vitamin A (Choice A) is important for vision and immune function, not specifically for calcium absorption. Vitamin K (Choice C) is essential for blood clotting, while Vitamin C (Choice D) is known for its role in collagen production and antioxidant properties, but not directly related to calcium absorption.

4. Which organ is responsible for the production of hormones during stress?

A. Parathyroid gland
B. Adrenal cortex
C. Posterior pituitary gland
D. Hypothalamus

Correct answer: B

Rationale: The adrenal cortex is the organ responsible for producing stress hormones like cortisol and aldosterone, which play a crucial role in the body's stress response. During stress, the adrenal cortex releases cortisol, a hormone that helps the body deal with stress by increasing blood sugar, suppressing the immune system, and aiding in metabolism. Parathyroid gland is responsible for calcium regulation, the posterior pituitary gland secretes hormones like oxytocin and vasopressin which are not directly related to the stress response, and the hypothalamus plays a role in regulating hormonal balance and various bodily functions but is not primarily responsible for producing stress hormones.

5. Which hormone is produced by the thyroid gland?

A. Insulin
B. Thyroxine
C. Glucagon
D. Cortisol

Correct answer: B

Rationale: Thyroxine is the hormone produced by the thyroid gland. It plays a crucial role in regulating metabolism, heart rate, and growth. Insulin is produced by the pancreas to regulate blood sugar levels, not by the thyroid gland. Glucagon is also produced by the pancreas and helps increase blood sugar levels. Cortisol is produced by the adrenal glands and is involved in stress response and metabolism, not by the thyroid gland.