PCAT Anatomy 4 — Questions and Answers
Question 1: Which valve prevents backflow of blood from the aorta into the left ventricle?
- Mitral valve
- Tricuspid valve
- Pulmonary valve
- Aortic semilunar valve (Correct answer)
Correct answer: Aortic semilunar valve
The aortic semilunar valve closes during ventricular diastole to prevent backflow of blood from the aorta into the left ventricle.
Question 2: The glomerulus is located within which structure of the nephron?
- Loop of Henle
- Bowman's capsule (Correct answer)
- Proximal convoluted tubule
- Collecting duct
Correct answer: Bowman's capsule
The glomerulus, a tuft of capillaries, is encased within Bowman's capsule (glomerular capsule) at the beginning of the nephron.
Question 3: Which structure connects the middle ear to the nasopharynx?
- External auditory canal
- Semicircular canal
- Eustachian tube (Correct answer)
- Cochlear duct
Correct answer: Eustachian tube
The Eustachian (pharyngotympanic) tube connects the middle ear to the nasopharynx, equalizing pressure across the tympanic membrane.
Question 4: The brachioradialis muscle is innervated by which nerve?
- Median nerve
- Ulnar nerve
- Radial nerve (Correct answer)
- Musculocutaneous nerve
Correct answer: Radial nerve
Despite acting as a forearm flexor, the brachioradialis is innervated by the radial nerve, making it an exception among forearm flexors.
Question 5: Which type of cartilage makes up the intervertebral discs?
- Hyaline cartilage
- Fibrocartilage (Correct answer)
- Elastic cartilage
- Articular cartilage
Correct answer: Fibrocartilage
Fibrocartilage, which contains abundant collagen fibers, forms the annulus fibrosus of intervertebral discs and withstands compressive forces.
Question 6: The inguinal canal in males transmits which structure?
- Femoral nerve
- Ilioinguinal nerve only
- Spermatic cord (Correct answer)
- External iliac artery
Correct answer: Spermatic cord
The inguinal canal in males transmits the spermatic cord, which contains the vas deferens, testicular vessels, and nerves.
Question 7: Which bone does NOT articulate with the talus?
- Calcaneus
- Navicular
- Tibia
- Cuboid (Correct answer)
Correct answer: Cuboid
The cuboid articulates with the calcaneus, not the talus; the talus articulates with the tibia, fibula, calcaneus, and navicular.
PCAT Anatomy 4
Which valve prevents backflow of blood from the aorta into the left ventricle?