primary peristalsis occurs in the

HESI A2

HESI A2 Anatomy and Physiology Practice Exam

1. Where does primary peristalsis occur?

A. Esophagus
B. Stomach
C. Nervous system
D. Small intestine

Correct answer: A

Rationale: Primary peristalsis occurs in the esophagus. Peristalsis is the coordinated muscular contractions that propel food through the digestive tract. In the esophagus, primary peristalsis is the involuntary wave-like contractions that push food from the mouth to the stomach. It is the natural and automatic process that occurs to facilitate the movement of food during digestion. The stomach (choice B), nervous system (choice C), and small intestine (choice D) are not the primary sites where peristalsis occurs in the digestive system.

2. What is the average normal body temperature in degrees Celsius?

A. 30°C
B. 32°C
C. 35°C
D. 37°C

Correct answer: D

Rationale: The average normal body temperature in degrees Celsius is 37°C. This temperature is considered the standard measurement for the human body under normal conditions. It is essential to know this baseline temperature for monitoring health and detecting abnormalities such as fever. Choice A, 30°C, is too low for the average normal body temperature. Choice B, 32°C, is also below the standard normal body temperature. Choice C, 35°C, is closer but still lower than the average normal body temperature of 37°C.

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

A. To absorb oxygen
B. To transport nutrients
C. To produce sound and speech
D. To regulate blood pressure

Correct answer: A

Rationale: The primary function of the respiratory system is to absorb oxygen from the air into the bloodstream and expel carbon dioxide from the body. This process is essential for cellular respiration and the production of energy in the body. Option A, 'To absorb oxygen,' aligns with this crucial function, making it the correct choice. Choices B, C, and D are incorrect as they do not represent the primary function of the respiratory system. The respiratory system is not responsible for transporting nutrients (choice B), producing sound and speech (choice C), or regulating blood pressure (choice D).

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. How does the lymphatic system work with the circulatory system?

A. The circulatory system produces red blood cells for the lymphatic system.
B. Lymph draws excess fluid from the cells and deposits it into the blood vessels.
C. The heart regulates the production of lymph in the lymph glands.
D. White cells from the lymphatic system eliminate excess red blood cells.

Correct answer: B

Rationale: The lymphatic system works with the circulatory system by draining excess fluid and waste products from the spaces between cells, known as interstitial fluid. This excess fluid, now called lymph, is then transported back into the blood circulation through lymphatic vessels. This process helps maintain fluid balance in the body and supports the circulatory system in regulating blood volume and pressure. Choice A is incorrect because the circulatory system does not produce red blood cells for the lymphatic system. Choice C is incorrect as the heart does not regulate lymph production in lymph glands. Choice D is incorrect as white cells from the lymphatic system do not eliminate excess red blood cells. Therefore, the correct answer is B, as lymph draws excess fluid from the cells and deposits it into the blood vessels, aiding in maintaining proper fluid balance and supporting the circulatory system.