PCAT Anatomy 5 — Questions and Answers
Question 1: Which muscle forms the posterior wall of the axilla?
- Pectoralis major
- Serratus anterior
- Subscapularis and teres major (Correct answer)
- Coracobrachialis
Correct answer: Subscapularis and teres major
The posterior wall of the axilla is formed by the subscapularis, teres major, and latissimus dorsi muscles.
Question 2: The portal triad in the liver consists of a portal venule, hepatic arteriole, and which third structure?
- Central vein
- Bile duct (Correct answer)
- Lymphatic vessel
- Hepatic vein
Correct answer: Bile duct
The portal triad (hepatic triad) consists of a branch of the portal vein, hepatic artery, and bile duct running together in the periportal space.
Question 3: Which nerve is at risk during a surgical removal of the submandibular gland?
- Facial nerve (CN VII)
- Lingual nerve
- Marginal mandibular branch of CN VII (Correct answer)
- Hypoglossal nerve
Correct answer: Marginal mandibular branch of CN VII
The marginal mandibular branch of the facial nerve, which controls lip depressors, is at risk during submandibular gland surgery.
Question 4: Transitional epithelium (urothelium) is characteristic of which organ?
- Small intestine
- Trachea
- Urinary bladder (Correct answer)
- Esophagus
Correct answer: Urinary bladder
Transitional epithelium lines the urinary bladder, ureters, and renal pelvis, allowing these organs to stretch and recoil.
Question 5: The circle of Willis is formed by the anastomosis of which two arterial systems?
- Subclavian and vertebral arteries
- Internal carotid and vertebrobasilar arteries (Correct answer)
- External and internal carotid arteries
- Anterior and middle cerebral arteries
Correct answer: Internal carotid and vertebrobasilar arteries
The circle of Willis is formed by anastomoses between the internal carotid arteries and the vertebrobasilar system via communicating arteries.
Question 6: Which muscle is primarily responsible for depression of the mandible (opening the mouth)?
- Masseter
- Temporalis
- Lateral pterygoid (Correct answer)
- Medial pterygoid
Correct answer: Lateral pterygoid
The lateral pterygoid muscle, aided by gravity and the suprahyoid muscles, is the primary muscle that depresses the mandible.
Question 7: The zona glomerulosa of the adrenal cortex produces which hormone?
- Cortisol
- DHEA
- Aldosterone (Correct answer)
- Epinephrine
Correct answer: Aldosterone
The outermost layer of the adrenal cortex, the zona glomerulosa, produces aldosterone, which regulates sodium and potassium balance.
PCAT Anatomy 5
Which muscle forms the posterior wall of the axilla?