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. What is the meaning of exocytosis?

A. The cell engulfs and brings in substances.
B. The cell releases content outside by fusing with the plasma membrane.
C. The cell engulfs liquid material.
D. The cell brings in solid particles.

Correct answer: B

Rationale: Exocytosis is the process by which a cell releases substances to the outside by fusing with the plasma membrane. During exocytosis, vesicles containing molecules fuse with the cell membrane, allowing the release of the contents outside the cell. This process is crucial for the secretion of various substances such as hormones, enzymes, and neurotransmitters. Choices A, C, and D are incorrect as they describe processes different from exocytosis. Choice A describes endocytosis, where the cell engulfs substances to bring them into the cell. Choice C is more aligned with pinocytosis, the process of engulfing liquid material. Choice D refers to phagocytosis, which is the uptake of solid particles by the cell.

3. Which of the following endocrine system glands releases the thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones?

A. Thymus
B. Pituitary gland
C. Pineal gland
D. Hypothalamus

Correct answer: D

Rationale: The correct answer is D, the Hypothalamus. The hypothalamus is responsible for releasing various essential hormones, including thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones. These hormones play crucial roles in regulating the functions of other endocrine glands by stimulating or inhibiting their hormone production. The Thymus (choice A) is primarily involved in the immune system, the Pituitary gland (choice B) secretes various hormones but not the ones specified in the question, and the Pineal gland (choice C) mainly produces melatonin, which regulates sleep-wake cycles, and is not related to the hormones mentioned in the question.

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

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

Correct answer: B

Rationale: The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the body, making it vital for systemic circulation. The right atrium receives deoxygenated blood from the body, the right ventricle pumps this blood to the lungs, and the left atrium receives oxygenated blood from the lungs.

5. Which is a secondary defense for the body against pathogens?

A. Tears
B. Urine
C. Inflammation
D. Mucus

Correct answer: C

Rationale: Inflammation is a secondary defense mechanism for the body against pathogens. When tissues are injured or infected, inflammation occurs as a protective response involving increased blood flow, white blood cell migration, and tissue repair. This process helps contain and eliminate pathogens, preventing them from spreading further in the body. Tears (Choice A) are a primary defense containing lysozyme and other antimicrobial agents. Urine (Choice B) is typically considered a non-specific defense mechanism due to its flushing action in the urinary tract. Mucus (Choice D) acts as a physical barrier and traps pathogens, also considered a primary defense mechanism.