Question 1

Which of the following best describes the difference between paracrine and endocrine signaling?

Accepted Answer

Paracrine signaling acts on neighboring cells within the same tissue, while endocrine signaling involves hormones released into the bloodstream to affect distant organs.

Question 2

A patient presents with symptoms of hyperthyroidism. Blood tests reveal elevated T3 and T4, but low TSH. Which of the following best explains this finding?

Accepted Answer

Negative feedback from high T3 and T4 is suppressing TSH release from the anterior pituitary.

Question 3

Which hormone is synthesized in the zona glomerulosa of the adrenal cortex, and what is its primary function?

Accepted Answer

Aldosterone; promotes sodium reabsorption in the kidneys

Question 4

Which of the following best describes the mechanism of action for peptide hormones?

Accepted Answer

They bind to cell surface receptors and often activate second messenger systems such as $$cAMP.$$

Question 5

A patient with a parathyroid tumor is producing excess PTH. Which of the following laboratory findings would you expect?

Accepted Answer

Increased blood calcium and decreased bone density

Question 6

Which of the following correctly matches the hormone with its source and primary effect?

Accepted Answer

Melatonin – pineal gland – regulates circadian rhythms

Question 7

Which of the following best explains why steroid hormones require carrier proteins in the bloodstream?

Accepted Answer

They are hydrophobic and poorly soluble in plasma.

Question 8

A patient is diagnosed with diabetes insipidus due to a deficiency of antidiuretic hormone (ADH). Which of the following symptoms would you expect?

Accepted Answer

Polyuria (excessive urination) and dehydration

Question 9

Which of the following best describes the role of the renin-angiotensin-aldosterone system (RAAS) in blood pressure regulation?

Accepted Answer

It increases blood pressure by stimulating vasoconstriction and sodium retention.

Question 10

Which of the following is an example of a permissive hormone interaction?

Accepted Answer

Thyroid hormone increasing the number of adrenergic receptors, enhancing the effect of epinephrine

Question 11

During the alarm phase of the General Adaptation Syndrome, which hormone is primarily responsible for the immediate 'fight or flight' response?

Accepted Answer

Epinephrine

Question 12

Which process is most directly affected by a deficiency of calcitriol?

Accepted Answer

Intestinal absorption of calcium

Question 13

A patient with Addison's disease has low cortisol and aldosterone levels. Which of the following symptoms would most likely be present?

Accepted Answer

Hypoglycemia and low blood pressure

Question 14

Which of the following best describes the feedback regulation of blood glucose by insulin and glucagon?

Accepted Answer

Insulin lowers blood glucose, while glucagon raises it, demonstrating antagonistic regulation.

Question 15

Which of the following scenarios best illustrates receptor down-regulation?

Accepted Answer

A cell decreases the number of hormone receptors after prolonged exposure to high hormone concentrations.

Question 16

Which of the following is a correct sequence of events in thyroid hormone synthesis?

Accepted Answer

Thyroglobulin synthesis → iodide uptake → thyroid peroxidase action → T3/T4 release

Question 17

Which hormone is released from the posterior pituitary and what is its primary effect?

Accepted Answer

Antidiuretic hormone (ADH); increases water reabsorption in the kidneys

Question 18

A patient with a tumor in the adrenal medulla is likely to have elevated levels of which hormone, and what symptoms might result?

Accepted Answer

Epinephrine; hypertension and tachycardia

Question 19

Which laboratory technique is commonly used to measure hormone concentrations in blood samples?

Accepted Answer

Enzyme-linked immunosorbent assay (ELISA)

Question 20

Which of the following best describes the effect of natriuretic peptides on blood pressure?

Accepted Answer

They decrease blood pressure by increasing sodium and water excretion.

Endocrine System: Comprehensive Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards