CBET Anatomy and Physiology Basics 4 — Questions and Answers
Question 1: Which layer of the skin contains melanocytes responsible for skin pigmentation?
- Stratum corneum
- Stratum basale (Correct answer)
- Stratum granulosum
- Stratum spinosum
Correct answer: Stratum basale
Melanocytes are located in the stratum basale (deepest layer of the epidermis) and produce melanin pigment.
Question 2: A biomedical technician is calibrating a pulse oximeter. Which physiological principle does this device rely on?
- Differential light absorption of oxygenated vs. deoxygenated hemoglobin (Correct answer)
- Electrical conductance of blood plasma
- Ultrasonic reflection from red blood cells
- Thermal dissipation of capillary blood flow
Correct answer: Differential light absorption of oxygenated vs. deoxygenated hemoglobin
Pulse oximeters use the fact that oxyhemoglobin and deoxyhemoglobin absorb red and infrared light at different ratios to calculate SpO2.
Question 3: The Frank-Starling law of the heart states that cardiac output increases when:
- Heart rate decreases below 60 bpm
- Ventricular filling volume (preload) increases (Correct answer)
- Afterload exceeds systemic vascular resistance
- Sympathetic tone is withdrawn
Correct answer: Ventricular filling volume (preload) increases
The Frank-Starling mechanism describes how increased end-diastolic volume stretches myocardial fibers, resulting in a stronger contraction and greater stroke volume.
Question 4: Which cranial nerve is primarily responsible for carrying parasympathetic fibers to the heart and abdominal organs?
- Trigeminal nerve (CN V)
- Glossopharyngeal nerve (CN IX)
- Vagus nerve (CN X) (Correct answer)
- Hypoglossal nerve (CN XII)
Correct answer: Vagus nerve (CN X)
The vagus nerve (CN X) provides the major parasympathetic innervation to the heart, lungs, and most abdominal organs.
Question 5: In the context of EEG monitoring, which brain wave frequency is associated with deep, dreamless sleep?
- Alpha waves (8–13 Hz)
- Beta waves (13–30 Hz)
- Theta waves (4–8 Hz)
- Delta waves (0.5–4 Hz) (Correct answer)
Correct answer: Delta waves (0.5–4 Hz)
Delta waves have the lowest frequency and highest amplitude and predominate during deep (stage 3–4) non-REM sleep.
Question 6: The glomerular filtration rate (GFR) is clinically important because it measures:
- The rate at which the bladder empties urine
- How effectively the kidneys filter blood plasma per unit time (Correct answer)
- The concentration of creatinine excreted in urine
- The reabsorption capacity of the proximal tubule
Correct answer: How effectively the kidneys filter blood plasma per unit time
GFR reflects the volume of plasma filtered by the glomeruli per minute and is the gold standard indicator of kidney function.
Question 7: Which type of muscle tissue is characterized by involuntary control, striated appearance, and intercalated discs?
- Skeletal muscle
- Smooth muscle
- Cardiac muscle (Correct answer)
- Multiunit smooth muscle
Correct answer: Cardiac muscle
Cardiac muscle is involuntary, striated, and connected by intercalated discs that allow synchronized contraction via gap junctions.
CBET Anatomy and Physiology Basics 4
Which layer of the skin contains melanocytes responsible for skin pigmentation?