which part of the brain controls voluntary movement

HESI A2

Anatomy HESI A2 Practice Test

1. Which part of the brain controls voluntary movement?

A. Cerebellum
B. Cerebrum
C. Brainstem
D. Medulla oblongata

Correct answer: B

Rationale: The cerebrum, specifically the motor cortex located within it, is responsible for controlling voluntary movements such as walking, writing, and speaking. This region of the brain plays a crucial role in coordinating and executing voluntary muscle actions, making it the correct answer in this context. The cerebellum (Choice A) primarily coordinates balance, posture, and coordination of voluntary movements but does not control voluntary movement itself. The brainstem (Choice C) is responsible for basic life functions like breathing and heart rate, not voluntary movements. The medulla oblongata (Choice D) controls vital functions like blood pressure and breathing, not voluntary movement.

2. What is the most visible part of the ear?

A. Ear canal
B. Cochlea
C. Organ of Corti
D. Pinna

Correct answer: D

Rationale: The pinna, also known as the auricle, is the most visible part of the ear. Its external shape and location make it easily noticeable on the side of the head. The pinna helps in capturing sound waves and directing them into the ear canal, where the sound transmission process begins. The other structures listed, the Organ of Corti, Cochlea, and Ear canal, are essential parts of the ear involved in hearing and sound processing, but they are not as visibly prominent as the pinna. Therefore, the correct answer is the pinna because of its external visibility and role in capturing sound waves.

3. Which structure in the ear is responsible for hearing?

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

Correct answer: A

Rationale: The cochlea, located in the inner ear, is responsible for detecting sound waves and converting them into neural signals that are sent to the brain for processing. It plays a crucial role in the process of hearing by translating mechanical vibrations into electrical signals that the brain can interpret as sound. The semicircular canals (Choice B) are responsible for balance and detecting head movements, not hearing. The ossicles (Choice C) are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the cochlea. The Eustachian tube (Choice D) helps equalize pressure between the middle ear and the atmosphere, but it is not directly involved in the process of hearing.

4. Which vitamin is essential for the maintenance of healthy skin?

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

Correct answer: A

Rationale: Vitamin A is the correct answer. It is crucial for maintaining healthy skin as it supports skin cell growth, repair, and overall skin health. Additionally, vitamin A plays a role in vision and immune function. Deficiency in vitamin A can lead to skin issues such as dryness and poor wound healing. Vitamin C is known for its role in collagen synthesis and antioxidant properties, while Vitamin D is important for bone health and immunity. Vitamin K is essential for blood clotting, but it is not primarily associated with skin health.

5. Which bones do the rotator cuff help to stabilize?

A. Radius and humerus
B. Scapula and clavicle
C. Humerus and scapula
D. Ulna and radius

Correct answer: C

Rationale: The correct answer is C: Humerus and scapula. The rotator cuff is a group of muscles and tendons that help stabilize the shoulder joint. Specifically, the rotator cuff muscles help to stabilize the head of the humerus (the upper arm bone) within the shallow socket of the scapula (shoulder blade). This stabilizing action is crucial for maintaining shoulder joint function and preventing injuries. Choices A, B, and D are incorrect because the rotator cuff primarily stabilizes the humerus and scapula, not the radius, ulna, or clavicle.