$TRH \rightarrow TSH \rightarrow T_3/T_4 \rightarrow \text{inhibition of TRH and TSH}$

$\text{Hypothalamus} \rightarrow \text{Pituitary} \rightarrow \text{Endocrine organ}$

Question 1

Which endocrine organ is located in the neck, anterior to the trachea, and is responsible for producing hormones that regulate metabolism?

Accepted Answer

Thyroid gland

Question 2

A patient presents with symptoms of increased heart rate, weight loss, and heat intolerance. Which endocrine organ is most likely overactive?

Accepted Answer

Thyroid gland

Question 3

Which of the following correctly matches the endocrine organ with its primary hormone product?

Accepted Answer

Thyroid gland — Thyroxine ($T_4$)

Question 4

The hypothalamus communicates with the anterior pituitary via which structure?

Accepted Answer

Infundibulum

Question 5

Which layer of the adrenal cortex is primarily responsible for producing aldosterone?

Accepted Answer

Zona glomerulosa

Question 6

A histological section shows spherical clusters of cells surrounded by capillaries in the pancreas. What are these structures called?

Accepted Answer

Islets of Langerhans

Question 7

Which hormone is secreted by the parafollicular cells of the thyroid gland, and what is its primary function?

Accepted Answer

Calcitonin — lowers blood calcium levels

Question 8

A patient with damage to the posterior pituitary would most likely have problems with which hormone?

Accepted Answer

Antidiuretic hormone (ADH)

Question 9

Which of the following best describes the function of the adrenal medulla?

Accepted Answer

Produces catecholamines like epinephrine and norepinephrine

Question 10

If a person’s parathyroid glands are accidentally removed during thyroid surgery, what physiological imbalance is most likely to occur?

Accepted Answer

Hypocalcemia

Question 11

Which endocrine organ is located in the sella turcica of the sphenoid bone?

Accepted Answer

Pituitary gland

Question 12

A histology slide shows round follicles filled with colloid and lined by cuboidal cells. Which organ is this?

Accepted Answer

Thyroid gland

Question 13

Which hormone is produced by the zona fasciculata of the adrenal cortex?

Accepted Answer

Cortisol

Question 14

A patient with diabetes mellitus has elevated blood glucose levels. Which pancreatic cells are most likely dysfunctional?

Accepted Answer

Beta cells

Question 15

Which of the following equations correctly represents the negative feedback regulation of thyroid hormone production?

Accepted Answer

$TRH ightarrow TSH ightarrow T_3/T_4 ightarrow 	ext{inhibition of TRH and TSH}$

Question 16

Which endocrine organ is responsible for producing hormones that regulate the female reproductive cycle?

Accepted Answer

Ovaries

Question 17

A tumor in the zona reticularis of the adrenal cortex would most likely affect the production of which type of hormone?

Accepted Answer

Androgens

Question 18

Which of the following best describes the role of the hypothalamus in endocrine regulation?

Accepted Answer

It produces releasing and inhibiting hormones that control the pituitary gland.

Question 19

A patient is found to have low levels of $T_3$ and $T_4$ but high levels of TSH. Which organ is most likely failing to respond appropriately?

Accepted Answer

Thyroid gland

Question 20

Which of the following is a correct sequence for the release of hormones from the hypothalamus to the target organ?

Accepted Answer

$	ext{Hypothalamus} ightarrow 	ext{Pituitary} ightarrow 	ext{Endocrine organ}$

Endocrine System: Organs, Structure, and Histology

Study Guide - Practice Questions