which organ system is primarily responsible for regulating muscle growth

HESI A2

Anatomy HESI A2

1. Which organ system is primarily responsible for regulating muscle growth?

A. The skeletal system
B. The endocrine system
C. The nervous system
D. The reproductive system

Correct answer: B

Rationale: The endocrine system is primarily responsible for regulating muscle growth through the production and release of hormones such as growth hormone, testosterone, and insulin-like growth factors. These hormones play crucial roles in stimulating muscle protein synthesis, increasing muscle mass, and promoting overall muscle growth and repair. The skeletal system provides structural support for muscles but does not directly regulate muscle growth. The nervous system controls muscle contractions and movements but is not primarily responsible for muscle growth. The reproductive system plays a role in fertility and secondary sexual characteristics but does not have a direct role in regulating muscle growth.

2. Which organ in the digestive system absorbs nutrients?

A. Stomach
B. Small intestine
C. Large intestine
D. Esophagus

Correct answer: B

Rationale: The small intestine is the primary site for nutrient absorption in the digestive system. It plays a crucial role in absorbing digested food into the bloodstream, where the nutrients are then circulated to the body's cells for energy and other functions. The stomach primarily breaks down food through the action of acids and enzymes, while the large intestine absorbs water and salts, not nutrients. The esophagus is a muscular tube that connects the mouth to the stomach and does not participate in nutrient absorption.

3. How does the skeletal system work with the nervous system?

A. The bones transmit signals about body position to the brain.
B. Pain nerves within bones notify the brain of injuries.
C. The vertebrae of the spine protect the spinal cord.
D. Bone marrow generates and houses nerve cells.

Correct answer: C

Rationale: The skeletal system collaborates with the nervous system by providing protection and support for critical nervous system components. The vertebrae of the spine play a crucial role in safeguarding the spinal cord, a key component of the nervous system responsible for transmitting messages between the brain and the body. Protecting the spinal cord is essential to prevent neurological complications. Choices A, B, and D are incorrect because while bones do play a role in body position and can sense pain, the primary focus of the skeletal system's interaction with the nervous system is to protect vital components like the spinal cord, rather than generating nerve cells.

4. What condition might result from a lack of vitamin C?

A. Kwashiorkor
B. Pellagra
C. Rickets
D. Scurvy

Correct answer: D

Rationale: Scurvy is the correct answer. Scurvy is a condition caused by a deficiency of vitamin C in the diet. Vitamin C is essential for collagen synthesis, and its deficiency leads to symptoms such as weakness, swollen and bleeding gums, joint pain, fatigue, and easy bruising. If left untreated, scurvy can lead to more severe complications. Choices A, B, and C are incorrect. Kwashiorkor is a severe form of malnutrition due to insufficient protein intake, pellagra is caused by a deficiency of niacin (vitamin B3), and rickets results from a deficiency of vitamin D, calcium, or phosphate.

5. Which hormone is released by the adrenal medulla?

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

Correct answer: B

Rationale: The correct answer is B, Adrenaline (also known as epinephrine), which is released by the adrenal medulla during the body's fight-or-flight response. Adrenaline helps prepare the body for action by increasing heart rate, dilating air passages, and mobilizing glucose and fats for energy, among other physiological responses. Choice A, Cortisol, is a steroid hormone released by the adrenal cortex involved in the stress response and regulation of metabolism. Choice C, Insulin, is produced by the pancreas and regulates blood sugar levels. Choice D, Somatostatin, is a hormone that inhibits the release of several other hormones in the body, but it is not released by the adrenal medulla.