Question 1

Which of the following best describes the sequence of events in the cAMP second-messenger mechanism used by protein hormones?

Accepted Answer

The hormone binds a plasma membrane receptor, which activates a G protein, leading to activation of adenylate cyclase, conversion of ATP to cAMP, and activation of protein kinases.

Question 2

A patient presents with muscle spasms and tetany. Laboratory tests reveal low blood calcium levels. Which hormone imbalance is most likely responsible?

Accepted Answer

Deficient parathyroid hormone (PTH) secretion

Question 3

During the menstrual cycle, which hormonal change triggers ovulation?

Accepted Answer

A surge in luteinizing hormone (LH) due to high estrogen levels switching to positive feedback

Question 4

Which of the following best explains why the left ventricular wall is thicker than the right ventricular wall?

Accepted Answer

The left ventricle pumps blood to the systemic circuit, which has higher resistance than the pulmonary circuit.

Question 5

Calculate the net filtration pressure (NFP) at the arterial end of a capillary given the following values: capillary hydrostatic pressure ($$HP_c) = 35 mm Hg$$, interstitial fluid hydrostatic pressure ($$HP_{if}) = 0 mm Hg$$, capillary colloid osmotic pressure ($$OP_c) = 26 mm Hg$$, interstitial fluid colloid osmotic pressure ($$OP_{if}) = 1 mm Hg. $$Use the formula $$NFP = (HP_c + OP_{if}) - (HP_{if} + OP_c).$$

Accepted Answer

$$NFP = (35 + 1) - (0 + 26) = 10 mm Hg$$, net movement out of the capillary

Question 6

A patient receives a transfusion of A+ blood but is O−. What is the most immediate and dangerous consequence?

Accepted Answer

The recipient's anti-A antibodies cause agglutination and hemolysis of donor RBCs, risking renal failure.

Question 7

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The more the cardiac muscle is stretched (increased preload), the more forceful the contraction and the greater the stroke volume.

Question 8

Which of the following is a correct sequence for the path of sperm from their site of production to the external urethral orifice?

Accepted Answer

Seminiferous tubule → epididymis → ductus deferens → ejaculatory duct → prostatic urethra → membranous urethra → spongy urethra

Question 9

Which of the following best explains why veins, but not arteries, have valves?

Accepted Answer

Veins operate under low pressure and need valves to prevent backflow of blood.

Question 10

A patient with Addison’s disease is likely to experience which of the following symptoms due to adrenal cortex insufficiency?

Accepted Answer

Low blood glucose, dehydration, weight loss, and hypotension

Question 11

Which of the following is a correct pairing of a capillary type with its primary location and function?

Accepted Answer

Sinusoid capillaries – found in bone marrow; allow passage of large molecules and cells

Question 12

Which of the following best describes the role of the hypothalamic-hypophyseal portal system?

Accepted Answer

It carries releasing and inhibiting hormones from the hypothalamus directly to the anterior pituitary.

Question 13

Which of the following is the correct order of events in the slow block to polyspermy during fertilization?

Accepted Answer

Sperm binds zona pellucida → acrosomal reaction → sperm entry → Ca²⁺ surge in oocyte → cortical reaction → ZIPs released → zona pellucida hardens

Question 14

Which of the following best explains the effect of baroreceptors when blood pressure falls below normal?

Accepted Answer

They decrease their firing rate, activating the cardioacceleratory and vasomotor centers, resulting in increased heart rate and vasoconstriction.

Question 15

Which of the following is a correct description of the three germ layers and their derivatives?

Accepted Answer

Ectoderm forms nervous system and skin; mesoderm forms muscle, bone, and connective tissue; endoderm forms epithelial linings of digestive and respiratory tracts.

Question 16

Which of the following best describes the effect of aldosterone on blood pressure?

Accepted Answer

It increases sodium and water reabsorption in the kidneys, raising blood volume and pressure.

Question 17

Which of the following is a correct statement about the intrinsic and extrinsic pathways of coagulation?

Accepted Answer

The extrinsic pathway is triggered by tissue factor and is faster than the intrinsic pathway.

Question 18

A patient with a mutation in the gene for von Willebrand factor would most likely have a defect in which step of hemostasis?

Accepted Answer

Platelet plug formation

Anatomy & Physiology II: Comprehensive Study Guide (Chapters 3, 16, 17, 18, 19, 27, 28)

Guida di studio - Domande di pratica

Study guide - Flashcard