MCAT Anatomy 5 — Questions and Answers
Question 1: The saphenous nerve, the largest cutaneous branch of the femoral nerve, accompanies which vessel in the leg?
- Popliteal artery
- Great saphenous vein (Correct answer)
- Small saphenous vein
- Posterior tibial artery
Correct answer: Great saphenous vein
The saphenous nerve runs with the great saphenous vein along the medial aspect of the leg, providing cutaneous innervation to the medial leg and foot.
Question 2: The parotid duct (Stensen's duct) pierces which muscle to enter the oral cavity?
- Masseter
- Medial pterygoid
- Buccinator (Correct answer)
- Superior pharyngeal constrictor
Correct answer: Buccinator
The parotid duct travels anteriorly, turns medially to pierce the buccinator muscle, and opens opposite the upper second molar.
Question 3: Which branch of the brachial plexus innervates the coracobrachialis, biceps brachii, and brachialis?
- Radial nerve
- Axillary nerve
- Musculocutaneous nerve (Correct answer)
- Median nerve
Correct answer: Musculocutaneous nerve
The musculocutaneous nerve (C5-C7) innervates all three muscles of the anterior compartment of the arm before continuing as the lateral cutaneous nerve of the forearm.
Question 4: The lymphatic drainage of the testes follows which vessels to drain into which lymph nodes?
- External iliac vessels to external iliac nodes
- Testicular (gonadal) vessels to para-aortic nodes (Correct answer)
- Inguinal vessels to superficial inguinal nodes
- Internal iliac vessels to internal iliac nodes
Correct answer: Testicular (gonadal) vessels to para-aortic nodes
The testes drain to para-aortic (lumbar) lymph nodes because the testes developed retroperitoneally near the kidneys before descending.
Question 5: The fovea centralis of the retina is specialized for high-acuity color vision and is densely packed with which photoreceptors?
- Rods only
- Cones only (Correct answer)
- Equal rods and cones
- Melanopsin-containing ganglion cells
Correct answer: Cones only
The fovea centralis contains only cones (no rods, no blood vessels) to maximize visual acuity and color discrimination in bright light.
Question 6: Which fontanelle is the last to close and is located at the junction of the sagittal and coronal sutures?
- Posterior (occipital) fontanelle
- Mastoid fontanelle
- Sphenoidal fontanelle
- Anterior (frontal) fontanelle (Correct answer)
Correct answer: Anterior (frontal) fontanelle
The anterior fontanelle, located at the bregma (junction of sagittal and coronal sutures), is the largest and last to close, typically around 18-24 months.
Question 7: The Achilles tendon is the combined tendon of which two muscles?
- Gastrocnemius and plantaris
- Soleus and plantaris
- Gastrocnemius and soleus (Correct answer)
- Soleus and flexor hallucis longus
Correct answer: Gastrocnemius and soleus
The calcaneal (Achilles) tendon is formed by the union of the gastrocnemius and soleus tendons, both of which plantarflex the foot.
MCAT Anatomy 5
The saphenous nerve, the largest cutaneous branch of the femoral nerve, accompanies which vessel in the leg?