CCMA Anatomy and Physiology Basics 4 — Questions and Answers
Question 1: Which layer of the skin contains the keratinocytes that produce the protein keratin?
- Dermis
- Epidermis (Correct answer)
- Hypodermis
- Subcutaneous fascia
Correct answer: Epidermis
Keratinocytes are the predominant cells of the epidermis and synthesize keratin to form a protective barrier.
Question 2: The sinoatrial (SA) node is located in which chamber of the heart?
- Left atrium
- Left ventricle
- Right atrium (Correct answer)
- Right ventricle
Correct answer: Right atrium
The SA node, the heart's natural pacemaker, is located in the upper wall of the right atrium.
Question 3: Which hormone is responsible for stimulating the reabsorption of sodium in the renal tubules?
- Aldosterone (Correct answer)
- Antidiuretic hormone
- Cortisol
- Renin
Correct answer: Aldosterone
Aldosterone, secreted by the adrenal cortex, promotes sodium reabsorption in the distal tubule and collecting duct.
Question 4: The brachial plexus originates from which spinal cord segments?
- C1–C4
- C5–T1 (Correct answer)
- T1–T5
- L1–L5
Correct answer: C5–T1
The brachial plexus arises from ventral rami of C5 through T1 and innervates the upper extremity.
Question 5: Which digestive enzyme, secreted by the pancreas, specifically cleaves peptide bonds adjacent to aromatic amino acids?
- Lipase
- Amylase
- Chymotrypsin (Correct answer)
- Trypsin
Correct answer: Chymotrypsin
Chymotrypsin cleaves peptide bonds on the carboxyl side of aromatic (phenylalanine, tyrosine, tryptophan) and large hydrophobic amino acids.
Question 6: The glomerular filtration rate (GFR) is primarily maintained by which mechanism when systemic blood pressure fluctuates?
- Hormonal regulation via aldosterone
- Tubuloglomerular feedback
- Renal autoregulation (Correct answer)
- Sympathetic vasoconstriction
Correct answer: Renal autoregulation
Renal autoregulation keeps GFR stable across a wide range of blood pressures through myogenic and tubuloglomerular mechanisms.
Question 7: Which cranial nerve controls the majority of parasympathetic innervation to thoracic and abdominal viscera?
- Cranial nerve III
- Cranial nerve VII
- Cranial nerve IX
- Cranial nerve X (Correct answer)
Correct answer: Cranial nerve X
The vagus nerve (CN X) provides parasympathetic innervation to the heart, lungs, and most abdominal organs as far as the splenic flexure.
CCMA Anatomy and Physiology Basics 4
Which layer of the skin contains the keratinocytes that produce the protein keratin?