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. How does a transverse section divide the body?

A. Into right and left regions
B. Into upper and lower regions
C. Into front and back regions
D. Between the dorsal and ventral cavities

Correct answer: B

Rationale: A transverse section, also known as a cross-section, divides the body into upper and lower regions. This type of section cuts across the body horizontally, creating a division between the superior (upper) and inferior (lower) portions of the body. Choice A is incorrect as dividing the body into right and left regions is typically done by a sagittal section. Choice C is incorrect as dividing the body into front and back regions is usually achieved by a frontal section. Choice D is incorrect as it refers more to the relationship between dorsal and ventral cavities rather than the actual division of the body.

3. What is the primary function of the respiratory system?

A. To remove carbon dioxide from the body
B. To transport oxygen to the cells
C. To deliver nutrients to cells
D. To create sound and speech

Correct answer: B

Rationale: The primary function of the respiratory system is to facilitate the exchange of gases. It transports oxygen from the air into the bloodstream, which is crucial for cellular respiration and providing energy to the cells. Additionally, it removes carbon dioxide, which is a waste product that needs to be eliminated. Choices A, C, and D are incorrect because while the respiratory system does remove carbon dioxide, its primary role is oxygen transport, not nutrient delivery, sound, or speech production.

4. Which type of blood cell is primarily responsible for fighting infections?

A. Red blood cells
B. White blood cells
C. Platelets
D. Plasma

Correct answer: B

Rationale: White blood cells, also known as leukocytes, play a crucial role in the immune system by primarily combating infections. These cells can identify and destroy pathogens, such as bacteria and viruses, helping the body defend against illnesses and maintain overall health. Red blood cells are responsible for oxygen transport, platelets aid in blood clotting, and plasma carries various components throughout the circulatory system, but none of these functions involve fighting infections like white blood cells do.

5. Which hormone initiates the preparation of the endometrium of the uterus for pregnancy?

A. FSH
B. Estrogen
C. LH
D. Progesterone

Correct answer: D

Rationale: Progesterone initiates the preparation of the endometrium of the uterus for pregnancy. It promotes the growth of blood vessels and glands in the endometrial lining, making it conducive for implantation and supporting early pregnancy. While estrogen helps in thickening the endometrium, it is progesterone that plays a crucial role in preparing it for pregnancy. FSH (Follicle-stimulating hormone) is involved in stimulating ovarian follicles, not directly in preparing the endometrium. LH (Luteinizing hormone) triggers ovulation but does not primarily prepare the endometrium for pregnancy.