Question 1

Which of the following best explains why the epithelium lining the respiratory tract changes from pseudostratified ciliated columnar in the trachea to simple squamous in the alveoli?

Accepted Answer

To facilitate efficient gas exchange by minimizing the diffusion distance for oxygen and carbon dioxide.

Question 2

A patient presents with a blockage in the ductus arteriosus after birth. Which adult structure is most likely affected, and what is its normal function in fetal circulation?

Accepted Answer

Ligamentum arteriosum; it is the remnant of the ductus arteriosus, which shunted blood from the pulmonary artery to the aorta in the fetus.

Question 3

Which of the following best describes the function of surfactant in the alveoli?

Accepted Answer

It decreases the surface tension, preventing alveolar collapse and making breathing easier.

Question 4

A patient with chronic hypertension is found to have thickened tunica media in their arteries. What is the primary function of the tunica media, and how does this adaptation affect blood flow?

Accepted Answer

The tunica media is composed mainly of smooth muscle, and thickening increases vasoconstriction, raising blood pressure.

Question 5

Which of the following correctly traces the path of blood through the heart, starting at the right atrium?

Accepted Answer

Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs → pulmonary vein → left atrium → bicuspid (mitral) valve → left ventricle → aortic valve → aorta

Question 6

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 entire systemic circuit, requiring greater pressure to overcome higher resistance.

Question 7

A patient is unable to voluntarily control urination due to nerve damage. Which muscle and sphincter are most likely affected?

Accepted Answer

External urethral sphincter (skeletal muscle), which is under voluntary control

Question 8

Which of the following best describes the function of the hepatic portal system?

Accepted Answer

It transports nutrient-rich blood from the digestive organs to the liver for processing before entering the systemic circulation.

Question 9

Which of the following is a correct statement about the structure and function of the nephron?

Accepted Answer

The glomerulus filters blood, and the filtrate enters Bowman’s capsule for further processing.

Question 10

A patient with a genetic defect lacks functional intercalated discs in their cardiac muscle. Which of the following symptoms would most likely result?

Accepted Answer

Decreased ability of the heart to contract as a coordinated unit, leading to arrhythmias.

Question 11

Which of the following best describes the role of the macula densa in the nephron?

Accepted Answer

It monitors sodium chloride concentration in the distal convoluted tubule and signals juxtaglomerular cells to adjust glomerular filtration rate.

Question 12

Which of the following is a function of the lymphatic system?

Accepted Answer

Returning excess interstitial fluid to the bloodstream and providing immune defense.

Question 13

Which of the following best explains why the testes are located outside the body cavity in the scrotum?

Accepted Answer

To maintain a temperature lower than core body temperature, which is necessary for normal spermatogenesis.

Question 14

Which of the following best describes the function of the acrosome cap in spermatozoa?

Accepted Answer

It contains enzymes that help the sperm penetrate the egg during fertilization.

Question 15

A patient with chronic obstructive pulmonary disease (COPD) has difficulty exhaling air from the lungs. Which muscles are primarily used during forced expiration?

Accepted Answer

Internal intercostals and abdominal muscles

Question 16

Which of the following best describes the function of the precapillary sphincters in a capillary bed?

Accepted Answer

They regulate the flow of blood into the capillaries based on tissue metabolic needs.

Question 17

Which of the following is a correct statement about the difference between the male and female urethra?

Accepted Answer

The male urethra is longer and transports both urine and semen, while the female urethra is shorter and only transports urine.

Question 18

Which of the following best describes the function of the blood-testis barrier?

Accepted Answer

It protects developing sperm from the immune system by preventing immune cells from accessing the seminiferous tubules.

Question 19

Which of the following best describes the function of the placenta in fetal circulation?

Accepted Answer

It allows for the exchange of gases, nutrients, and wastes between maternal and fetal blood without mixing the two blood supplies.

Question 20

Which of the following is a function of the spleen in the lymphatic system?

Accepted Answer

It filters blood, removes old red blood cells, and initiates immune responses to blood-borne pathogens.

Anatomy & Physiology Study Guide: Cardiovascular, Respiratory, Urinary, Reproductive, Blood, and Lymphatic Systems

Study Guide - Practice Questions

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