Question 1

Which of the following best describes the mechanism by which peptide hormones exert their effects on target cells?

Accepted Answer

They dissolve in blood plasma and bind to membrane-bound receptors, often activating second messengers such as $$	ext{cAMP} or$$ $$	ext{Ca}^{2+}.$$

Question 2

A patient presents with excessive urination, intense thirst, and a history of head trauma. Blood tests show normal glucose levels. Which hormone is most likely deficient, and what is the underlying mechanism?

Accepted Answer

Antidiuretic hormone (ADH); failure to promote water reabsorption in the kidneys.

Question 3

Which of the following hormones is synthesized in the hypothalamus and released from the posterior pituitary, and what is its primary function?

Accepted Answer

Oxytocin; stimulates smooth muscle contraction in the uterus and milk ejection.

Question 4

A patient with a non-cancerous tumor in the anterior pituitary before puberty is likely to develop which disorder, and what is the physiological basis?

Accepted Answer

Gigantism; excessive growth hormone secretion before epiphyseal plates have sealed.

Question 5

Which hormone is released in response to low blood calcium levels, and what are its effects on bone and kidneys?

Accepted Answer

Parathyroid hormone (PTH); increases osteoclast activity in bone and enhances calcium reabsorption in kidneys.

Question 6

A patient with high blood glucose, increased thirst, frequent urination, and an HbA1c of 7.2% is most likely suffering from which disorder, and what is the diagnostic threshold for diabetes using HbA1c?

Accepted Answer

Diabetes mellitus; HbA1c $$\geq 6.5\%$$

Question 7

Which of the following best explains the development of a goiter in a patient with dietary iodine deficiency?

Accepted Answer

Lack of T3 and T4 prevents negative feedback, resulting in increased TSH and thyroid gland enlargement.

Question 8

During the resistance phase of the general adaptation syndrome (GAS), which hormones are primarily involved in mobilizing energy reserves and conserving glucose for neuronal tissues?

Accepted Answer

Glucocorticoids (cortisol), growth hormone, and glucagon

Question 9

Which hormone is secreted from the zona glomerulosa of the adrenal cortex, and what is its primary effect?

Accepted Answer

Aldosterone; increases sodium reabsorption in the kidneys.

Question 10

A patient with symptoms of fatigue, weight loss, muscle weakness, low blood pressure, and darkening of the skin is most likely suffering from which adrenal disorder?

Accepted Answer

Addison disease

Question 11

Which hormone is released in response to excessive stretching of the heart wall, and what is its effect on blood volume and pressure?

Accepted Answer

Natriuretic peptides; promote water and sodium loss, lowering blood volume and pressure.

Question 12

Which of the following is a permissive hormonal interaction, where the presence of one hormone allows the effects of another to occur?

Accepted Answer

Epinephrine and thyroid hormones

Question 13

A patient with bulging eyes, rapid heart rate, irritability, and non-painful swelling of the thyroid is most likely suffering from which disorder, and what is the underlying cause?

Accepted Answer

Hyperthyroidism (Grave's disease); autoimmune antibodies disrupt thyroid function

Question 14

Which hormone is produced by parafollicular cells of the thyroid gland, and what is its effect on blood calcium levels?

Accepted Answer

Calcitonin; lowers blood calcium levels by increasing calcium deposition in bone and stimulating excretion in kidneys.

Question 15

Which hormone is secreted by alpha cells in the pancreatic islets, and what is its primary effect?

Accepted Answer

Glucagon; increases breakdown of glycogen in the liver and elevates blood glucose.

Question 16

A patient with low body temperature, dry skin, hair loss, fatigue, and memory problems is most likely suffering from which endocrine disorder?

Accepted Answer

Hypothyroidism (Hashimoto's disease, Myxedema)

Question 17

Which hormone is synthesized from serotonin in the pineal gland, and what is its primary function?

Accepted Answer

Melatonin; regulates circadian rhythms and suppresses reproductive activity.

Question 18

A patient with round face, increased upper body fat, thin arms and legs, high blood glucose, and high blood pressure is most likely suffering from which disorder, and what is the primary hormone involved?

Accepted Answer

Cushing disease; cortisol excess

Question 19

Which of the following best describes the transport of thyroid hormones in the bloodstream?

Accepted Answer

They are bound to thyroid-binding globulins and circulate for extended periods.

Question 20

Which hormone is released from the adrenal medulla during the alarm phase of the general adaptation syndrome, and what is its effect?

Accepted Answer

Epinephrine; increases cardiac activity, blood pressure, and mobilizes energy reserves.

Chapter 16: The Endocrine System – Anatomy & Physiology II Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards