which part of the brain is responsible for regulating involuntary functions such as breathing and heart rate

HESI A2

Anatomy HESI A2

1. Which part of the brain is responsible for regulating involuntary functions such as breathing and heart rate?

A. Cerebrum
B. Cerebellum
C. Medulla oblongata
D. Frontal lobe

Correct answer: C

Rationale: The medulla oblongata, located in the brain stem, is responsible for regulating involuntary functions such as breathing and heart rate. It contains vital centers that control these essential functions to maintain life. The cerebrum is primarily involved in higher brain functions like thinking and voluntary movements; the cerebellum plays a crucial role in coordinating movement and balance; and the frontal lobe is responsible for functions such as decision-making, problem-solving, and voluntary muscle movements. Therefore, the correct answer is the medulla oblongata (Choice C).

2. Which structure in the ear is responsible for balance?

A. Cochlea
B. Semicircular canals
C. Ossicles
D. Eustachian tube

Correct answer: B

Rationale: The semicircular canals in the inner ear are responsible for maintaining balance by detecting changes in head position and movement. These structures contain fluid and hair cells that send signals to the brain regarding the body's orientation in space, helping us stay balanced and navigate our surroundings. The cochlea is responsible for hearing, the ossicles are involved in sound transmission, and the Eustachian tube helps equalize pressure in the middle ear, but they are not directly related to balance.

3. Which type of nutrient does not provide the body with energy?

A. Vitamin
B. Carbohydrate
C. Fat
D. Protein

Correct answer: A

Rationale: The correct answer is A. Vitamins are essential nutrients that the body needs in small amounts but do not provide energy like carbohydrates, fats, and proteins do. Carbohydrates, fats, and proteins are macronutrients that supply energy to the body when broken down during metabolism. Vitamins, on the other hand, play crucial roles in various bodily functions but are not a source of energy. They are essential for supporting growth, immune function, and overall health, but do not contribute directly to energy production. Choices B, C, and D are incorrect because carbohydrates, fats, and proteins are macronutrients that provide energy to the body when metabolized.

4. 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.

5. Which type of joint is found in the knee?

A. Ball and socket joint
B. Hinge joint
C. Pivot joint
D. Saddle joint

Correct answer: B

Rationale: The correct answer is a hinge joint. The knee is a hinge joint that allows for flexion and extension movements, enabling the leg to bend and straighten. This type of joint is designed for movement along one plane, similar to a door hinge. Choice A, ball and socket joint, is incorrect as this type of joint allows for a wider range of motion in multiple directions, unlike the knee joint. Choice C, pivot joint, and Choice D, saddle joint, are also incorrect as they do not accurately describe the type of joint found in the knee.