which gland is often referred to as the master gland

HESI A2

HESI A2 Practice Test Anatomy and Physiology

1. Which gland is often referred to as the 'master gland'?

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

Correct answer: B

Rationale: The pituitary gland is often referred to as the 'master gland' because it controls the release of hormones from other endocrine glands in the body. It secretes a variety of hormones that regulate various bodily functions and play a crucial role in maintaining homeostasis. The thyroid gland (Choice A) plays a role in regulating metabolism, the adrenal gland (Choice C) secretes hormones involved in stress response, and the pineal gland (Choice D) produces melatonin to regulate sleep-wake cycles, but they are not known as the 'master gland' due to their functions.

2. Where are B-lymphocytes produced?

A. Thymus
B. Red bone marrow
C. Lymph nodes
D. Spleen

Correct answer: B

Rationale: B-lymphocytes are produced in the red bone marrow. The red bone marrow is the primary site for B-cell development, where they mature before entering the circulation. The thymus is responsible for T-lymphocyte maturation, not B-lymphocytes. Lymph nodes and spleen play roles in immune responses but are not the primary sites for B-lymphocyte production.

3. The motor cortex helps the brain by monitoring and controlling the body's movement. Where is the motor cortex located within the brain?

A. Back of the head
B. Top middle portion of the parietal lobe
C. Front portion of the parietal lobe
D. Around the auditory cortex

Correct answer: C

Rationale: The correct answer is C: Front portion of the parietal lobe. The motor cortex is located in the frontal lobe, specifically in the front portion of the parietal lobe. It is responsible for planning, controlling, and executing voluntary movements. Choices A, B, and D are incorrect as the motor cortex is not located at the back of the head, top middle portion of the parietal lobe, or around the auditory cortex.

4. Which of the following is not a component of the central nervous system?

A. Brain
B. Heart
C. Retina
D. Spinal cord

Correct answer: B

Rationale: The central nervous system comprises the brain and spinal cord, responsible for processing and transmitting information. The retina, though part of the eye, is an extension of the central nervous system. However, the heart is part of the circulatory system, responsible for pumping blood throughout the body. Therefore, the correct answer is the heart as it is not a component of the central nervous system.

5. Which of the heart's four chambers is the largest and the strongest?

A. Left ventricle
B. Left atrium
C. Right ventricle
D. Right atrium

Correct answer: A

Rationale: The correct answer is the left ventricle. The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the entire body, making it a vital component of the circulatory system. The left atrium receives oxygen-rich blood from the lungs, the right ventricle pumps deoxygenated blood to the lungs for oxygenation, and the right atrium receives deoxygenated blood from the body.