Question 1

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

Accepted Answer

They bind to plasma membrane receptors and activate second messenger systems, often involving G-proteins.

Question 2

A patient presents with weight loss, heat intolerance, and exophthalmos. Which hormone is most likely elevated, and what is the primary feedback mechanism regulating its secretion?

Accepted Answer

Thyroid hormone; negative feedback loop involving TRH and TSH

Question 3

Which equation correctly represents the half-life ($$t_{1/2}) of a $$hormone, given its initial concentration ($$C_0) $$and its concentration after time $$t$$ ($$C_t$$)?

Accepted Answer

$$t_{1/2} = \frac{t \cdot \ln(2)}{\ln\left(\frac{C_0$}{C_t}\right)}$$

Question 4

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

Accepted Answer

Aldosterone; increases sodium ion retention and potassium ion loss

Question 5

A patient with hypoglycemia is found to have abnormally high insulin levels. Which of the following best explains the physiological effect of insulin in this scenario?

Accepted Answer

Insulin stimulates glucose uptake by cells, decreasing blood glucose.

Question 6

Which of the following hormones is produced by the posterior pituitary and acts on the kidneys to promote water retention?

Accepted Answer

Antidiuretic hormone (ADH)

Question 7

Which of the following best describes the role of parathyroid hormone (PTH) in calcium homeostasis?

Accepted Answer

PTH increases blood calcium by stimulating osteoclasts and enhancing calcium absorption in the intestine and kidneys.

Question 8

Which hormone is secreted by the pineal gland and what is its primary function?

Accepted Answer

Melatonin; regulates the sleep/wake cycle

Question 9

A patient with hyperthyroidism is likely to experience which of the following symptoms due to increased thyroid hormone levels?

Accepted Answer

Weight loss, heat intolerance, and disruptions in heart rhythm

Question 10

Which of the following best explains the difference between endocrine and neuroendocrine organs?

Accepted Answer

Endocrine organs secrete hormones into the bloodstream, while neuroendocrine organs secrete neurohormones produced by neurons.

Question 11

Which hormone is produced by the beta ($$\beta) $$cells of the pancreatic islets, and what is its main function?

Accepted Answer

Insulin; stimulates uptake of glucose, fats, and amino acids by cells

Question 12

Which of the following hormones is involved in the acute effects of growth hormone and what is its primary action?

Accepted Answer

Growth hormone; stimulates lipogenesis and gluconeogenesis

Question 13

Which hormone is secreted by cardiac muscle cells and what is its effect on the kidneys?

Accepted Answer

Atrial natriuretic peptide (ANP); promotes vasodilation and water loss

Question 14

Which of the following best describes the feedback loop regulating cortisol secretion?

Accepted Answer

Negative feedback loop involving the hypothalamic-pituitary-adrenal (HPA) axis

Question 15

Which hormone is responsible for stimulating erythrocyte development, and which organ produces it?

Accepted Answer

Erythropoietin; kidneys

Question 16

A patient with a tumor in the anterior pituitary is found to have elevated levels of adrenocorticotropic hormone (ACTH). Which of the following is a likely consequence?

Accepted Answer

Increased secretion of cortisol from the adrenal cortex

Question 17

Which hormone is secreted by parafollicular cells of the thyroid gland, and what is its effect on bone remodeling?

Accepted Answer

Calcitonin; inhibits osteoclasts at high concentrations

Question 18

Which of the following best describes the effect of leptin produced by adipose tissue?

Accepted Answer

Leptin induces satiety by acting on the hypothalamus.

Question 19

Which equation best represents the relationship between plasma volume ($$V$$), plasma solute concentration ($$C$$), and ADH secretion?

Accepted Answer

ADH secretion increases as $$V$$ decreases and $$C$$ increases.

Question 20

Which hormone is secreted by the thymus and what is its primary function?

Accepted Answer

Thymosin; stimulates T lymphocyte maturation

The Endocrine System: Structure, Function, and Regulation

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드