WGU D313 Anatomy and Physiology II Objective Assessment 2025/2026 – 70 Questions with Correct Verified Answers & Rationales

WGU D313 Anatomy and Physiology II
Objective Assessment 2025/2026 – 70
Questions with Correct Verified Answers
& Rationales
Question 1
Which hormone primarily regulates blood calcium levels?
A) Insulin
B) Parathyroid hormone
C) Cortisol
D) Thyroxine

B) Parathyroid hormone

Rationale: Parathyroid hormone (PTH) increases blood calcium by stimulating bone resorption,
renal calcium reabsorption, and vitamin D activation. Insulin regulates glucose, cortisol affects
stress response, and thyroxine influences metabolism.

Question 2
The nephron’s primary site for filtration is:
A) Proximal convoluted tubule
B) Glomerulus
C) Loop of Henle
D) Collecting duct

B) Glomerulus

Rationale: The glomerulus, a capillary network, filters blood to form filtrate in Bowman’s
capsule. Other structures reabsorb or secrete substances post-filtration.

Question 3
What is the function of the alveoli in the lungs?
A) Secretion of mucus
B) Gas exchange
C) Filtration of air
D) Production of surfactant

,B) Gas exchange

Rationale: Alveoli are thin-walled sacs where oxygen and carbon dioxide diffuse between air and
blood. Surfactant production occurs in type II alveolar cells, but gas exchange is the primary
function.

Question 4
Which structure connects the testes to the urethra?
A) Epididymis
B) Vas deferens
C) Seminal vesicle
D) Prostate gland

B) Vas deferens

Rationale: The vas deferens transports sperm from the epididymis to the urethra. The epididymis
stores sperm, while seminal vesicles and the prostate contribute seminal fluid.

Question 5
The hormone erythropoietin is primarily produced by:
A) Liver
B) Kidneys
C) Bone marrow
D) Spleen

B) Kidneys

Rationale: Kidneys produce erythropoietin to stimulate red blood cell production in bone
marrow, especially in response to hypoxia.

Question 6
What is the role of the sinoatrial (SA) node in the heart?
A) Conducts electrical impulses to the ventricles
B) Acts as the heart’s pacemaker
C) Regulates blood pressure
D) Filters blood

B) Acts as the heart’s pacemaker

Rationale: The SA node initiates electrical impulses, setting the heart’s rhythm. The
atrioventricular node and Purkinje fibers conduct impulses to ventricles.

, Question 7
The primary function of the large intestine is:
A) Nutrient absorption
B) Water reabsorption
C) Protein digestion
D) Bile production

B) Water reabsorption

Rationale: The large intestine reabsorbs water and forms feces. Nutrient absorption occurs
mainly in the small intestine, and bile is produced by the liver.

Question 8
Which hormone triggers ovulation in females?
A) Estrogen
B) Progesterone
C) Luteinizing hormone (LH)
D) Follicle-stimulating hormone (FSH)

C) Luteinizing hormone (LH)

Rationale: A surge in LH triggers ovulation by causing the mature follicle to rupture. FSH
supports follicle growth, while estrogen and progesterone regulate the menstrual cycle.

Question 9
The renal artery supplies blood to which organ?
A) Liver
B) Kidney
C) Pancreas
D) Spleen

B) Kidney

Rationale: The renal artery delivers oxygenated blood to the kidneys for filtration and urine
production.

Question 10
What is the primary source of energy for red blood cells?
A) Fatty acids
B) Glucose