UExcel Anatomy and Physiology 5 — Questions and Answers
Question 1: Which bone is NOT part of the axial skeleton?
- Sternum
- Sacrum
- Scapula (Correct answer)
- Hyoid
Correct answer: Scapula
The scapula (shoulder blade) is part of the appendicular skeleton, while the sternum, sacrum, and hyoid are axial skeleton components.
Question 2: The hypothalamus regulates body temperature primarily by acting as a:
- Chemoreceptor
- Thermostat set point (Correct answer)
- Heat generator
- Sweat gland regulator only
Correct answer: Thermostat set point
The hypothalamus acts as the body's thermostat, comparing core temperature to a set point and triggering corrective responses (shivering, sweating).
Question 3: In a negative feedback loop controlling thyroid hormone levels, elevated T3 and T4 would cause:
- Increased TSH secretion from the anterior pituitary
- Decreased TSH secretion from the anterior pituitary (Correct answer)
- Increased TRH release from the hypothalamus
- Increased iodine absorption by the thyroid
Correct answer: Decreased TSH secretion from the anterior pituitary
High T3/T4 levels feed back to inhibit TSH release from the anterior pituitary and TRH from the hypothalamus, reducing further thyroid stimulation.
Question 4: Which type of synovial joint allows the widest range of motion, including flexion, extension, abduction, and rotation?
- Hinge joint
- Pivot joint
- Ball-and-socket joint (Correct answer)
- Saddle joint
Correct answer: Ball-and-socket joint
Ball-and-socket joints (e.g., shoulder, hip) allow multiaxial movement including flexion, extension, abduction, adduction, and rotation.
Question 5: Which protein complex in the thick filaments of skeletal muscle contains the ATPase activity needed for muscle contraction?
- Troponin
- Tropomyosin
- Actin
- Myosin (Correct answer)
Correct answer: Myosin
Myosin heads possess ATPase activity, hydrolyzing ATP to generate the power stroke that pulls actin filaments during contraction.
Question 6: The blood-brain barrier is primarily formed by:
- Microglia
- Oligodendrocytes
- Tight junctions between capillary endothelial cells (Correct answer)
- Astrocyte cell bodies
Correct answer: Tight junctions between capillary endothelial cells
Tight junctions between brain capillary endothelial cells form the structural basis of the blood-brain barrier, restricting passage of most substances.
Question 7: Which division of the autonomic nervous system increases heart rate and dilates bronchioles in a 'fight-or-flight' response?
- Somatic nervous system
- Parasympathetic division
- Sympathetic division (Correct answer)
- Enteric nervous system
Correct answer: Sympathetic division
The sympathetic division releases norepinephrine (and epinephrine from the adrenal medulla), increasing heart rate and dilating airways during stress.
UExcel Anatomy and Physiology 5
Which bone is NOT part of the axial skeleton?