CABT Anatomy and Physiology Fundamentals 4 — Questions and Answers
Question 1: Which hormone is produced by the adrenal medulla and plays a key role in the 'fight-or-flight' response?
- Cortisol
- Aldosterone
- Epinephrine (Correct answer)
- Insulin
Correct answer: Epinephrine
The adrenal medulla secretes epinephrine (adrenaline) and norepinephrine in response to sympathetic nervous system activation during stress.
Question 2: A pulse oximeter measures oxygen saturation using light absorption. Which property of hemoglobin makes this possible?
- Hemoglobin changes molecular weight when bound to oxygen
- Oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently (Correct answer)
- Hemoglobin fluoresces under UV light when oxygenated
- Oxygen binding increases hemoglobin's electrical conductivity
Correct answer: Oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently
Pulse oximeters exploit the different light absorption spectra of oxyhemoglobin (red light) and deoxyhemoglobin (infrared light) to calculate SpO2.
Question 3: Which of the following accurately describes the function of the blood-brain barrier (BBB)?
- It prevents all nutrients from entering the brain
- It selectively restricts the passage of substances between blood and brain tissue (Correct answer)
- It is formed by neurons in the cerebral cortex
- It regulates the flow of cerebrospinal fluid between ventricles
Correct answer: It selectively restricts the passage of substances between blood and brain tissue
The BBB, formed by tight junctions between brain capillary endothelial cells and supported by astrocyte endfeet, selectively controls what enters brain tissue.
Question 4: In a patient with a fractured femur, which artery is at greatest risk of injury due to its proximity to the bone in the femoral shaft?
- Femoral artery
- Popliteal artery
- Tibial artery
- Perforating branches of the deep femoral artery (Correct answer)
Correct answer: Perforating branches of the deep femoral artery
Perforating branches of the profunda femoris (deep femoral artery) run close to the femoral shaft and are commonly injured in mid-shaft femur fractures.
Question 5: What is the role of the sinoatrial (SA) node in cardiac physiology?
- It delays conduction between atria and ventricles
- It initiates the electrical impulse that sets the heart rate (Correct answer)
- It supplies blood to the conduction system
- It controls valve opening and closing
Correct answer: It initiates the electrical impulse that sets the heart rate
The SA node, located in the right atrium, spontaneously depolarizes at 60–100 bpm, acting as the natural pacemaker of the heart.
Question 6: Which section of the small intestine is the primary site for nutrient absorption?
- Duodenum
- Jejunum (Correct answer)
- Ileum
- Cecum
Correct answer: Jejunum
The jejunum has extensive villi and microvilli (brush border) and is the primary site for absorption of carbohydrates, proteins, and most nutrients.
Question 7: A biomedical technician services a patient warming system. Which physiological mechanism does this device support by maintaining core body temperature?
- Osmoregulation
- Thermoregulation (Correct answer)
- Glucoregulation
- Hematopoiesis
Correct answer: Thermoregulation
Thermoregulation maintains core body temperature within narrow limits (36.5–37.5°C) to ensure optimal enzymatic function and cellular processes.
CABT Anatomy and Physiology Fundamentals 4
Which hormone is produced by the adrenal medulla and plays a key role in the 'fight-or-flight' response?