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. The arteries are part of which system?

A. Nervous system
B. Endocrine system
C. Lymphatic system
D. Cardiovascular system

Correct answer: D

Rationale: The correct answer is D, Cardiovascular system. Arteries are blood vessels that carry oxygen-rich blood away from the heart to various parts of the body. They are a key component of the cardiovascular system, which is responsible for transporting blood, nutrients, and oxygen throughout the body. The other options (A, B, and C) are incorrect because arteries are not part of the nervous system, endocrine system, or lymphatic system.

3. What is the main function of the urinary bladder?

A. To filter blood
B. To store and concentrate bile
C. To store urine
D. To absorb nutrients

Correct answer: C

Rationale: The correct answer is C: To store urine. The main function of the urinary bladder is to store urine produced by the kidneys before it is excreted from the body. It acts as a reservoir for urine until it is expelled during urination. Choices A, B, and D are incorrect because the urinary bladder does not filter blood, store or concentrate bile, or absorb nutrients. It is solely responsible for storing and releasing urine.

4. Which structure in the eye is responsible for focusing light on the retina?

A. Cornea
B. Lens
C. Retina
D. Pupil

Correct answer: B

Rationale: The lens of the eye is responsible for focusing light onto the retina. It plays a crucial role in bending light rays to ensure that they converge on the retina, enabling clear vision. The cornea helps in focusing light, but the final adjustment and fine-tuning occur through the lens. The retina receives the focused light and converts it into neural signals for the brain to interpret. The pupil, on the other hand, controls the amount of light entering the eye by dilating or constricting.

5. Which vitamin is necessary for the absorption of calcium?

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

Correct answer: B

Rationale: Vitamin D is the correct answer. It is essential for the absorption of calcium in the intestines, facilitating the maintenance of strong bones and teeth. Vitamin D helps regulate calcium levels in the blood and promotes bone mineralization, making it crucial for overall bone health. Choices A, C, and D are incorrect because Vitamin C is not directly involved in calcium absorption, Vitamin A is more related to vision and immune function, and Vitamin K plays a role in blood clotting and bone mineralization but is not primarily responsible for calcium absorption.