how does a sagittal section divide the body

HESI A2

Anatomy HESI A2

1. How does a sagittal 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: A

Rationale: A sagittal section divides the body into right and left regions. This type of section runs longitudinally from front to back, separating the body into right and left halves. Sagittal sections are crucial for understanding the anatomical structure and orientation of various body parts. Choices B, C, and D are incorrect because a sagittal section specifically divides the body into right and left portions, not upper and lower regions, front and back regions, or between the dorsal and ventral cavities.

2. Which neurotransmitter controls sleep, mood, and appetite?

A. Serotonin
B. Oxytocin
C. Cortisol
D. Aldosterone

Correct answer: A

Rationale: Serotonin is the correct answer. It is a neurotransmitter that plays a crucial role in regulating mood, sleep, and appetite. Serotonin functions to stabilize and control these physiological processes in the brain and body. Imbalances in serotonin levels are commonly linked to conditions like depression, anxiety, and eating disorders. Oxytocin (Choice B) is more associated with social bonding and childbirth. Cortisol (Choice C) is a stress hormone, and while it can influence mood and appetite in response to stress, it is not primarily responsible for regulating these functions. Aldosterone (Choice D) is a hormone that regulates electrolyte balance and blood pressure, not mood, sleep, and appetite.

3. How do the intercostal muscles between the ribs assist with respiration?

A. By protecting the delicate bronchioles and alveoli
B. By signaling a decrease in intra-alveolar pressure
C. By enlarging and reducing the space in the thorax
D. By maintaining a medial separation between pleurae

Correct answer: C

Rationale: The intercostal muscles located between the ribs play a crucial role in respiration by aiding in the enlargement and reduction of the space in the thorax. During inspiration, these muscles contract, lifting the rib cage, which increases the volume of the thoracic cavity and allows the lungs to expand and fill with air. This process directly relates to the expansion of the thorax rather than protecting bronchioles and alveoli (Choice A), signaling intra-alveolar pressure changes (Choice B), or maintaining the separation between pleurae (Choice D). Therefore, the correct answer is C.

4. Which gland produces hormones that regulate sleep?

A. Thyroid gland
B. Pineal gland
C. Adrenal gland
D. Pituitary gland

Correct answer: B

Rationale: The pineal gland secretes melatonin, a hormone that plays a crucial role in regulating the sleep-wake cycle. Melatonin production is influenced by exposure to light, with levels increasing in the evening to promote sleep and decreasing in the morning to signal wakefulness. Choices A, C, and D are incorrect because the thyroid gland primarily regulates metabolism, the adrenal gland produces hormones like adrenaline and cortisol related to stress response, and the pituitary gland controls various functions by releasing different hormones but not specifically related to regulating sleep.

5. Which structure is part of both the male reproductive system and the urinary system?

A. Bladder
B. Urethra
C. Prostate
D. Seminal Vesicle

Correct answer: B

Rationale: The urethra is the correct answer because it is a tube that is part of both the male reproductive system and the urinary system. It allows urine to pass out of the body as part of the urinary system and also transports semen as part of the male reproductive system. The bladder (Choice A) is solely part of the urinary system, storing urine. The prostate (Choice C) is part of the male reproductive system, secreting fluids that nourish and protect sperm. The seminal vesicle (Choice D) is also part of the male reproductive system, producing seminal fluid that mixes with sperm to form semen.