BHS Anatomy and Physiology 4 — Questions and Answers
Question 1: Which muscle is the prime mover for elbow flexion when the forearm is supinated?
- Brachioradialis
- Triceps brachii
- Biceps brachii (Correct answer)
- Anconeus
Correct answer: Biceps brachii
The biceps brachii is the primary elbow flexor when the forearm is supinated, aided by the brachialis and brachioradialis.
Question 2: The blood-brain barrier is primarily formed by:
- Microglia tight junctions
- Astrocyte end-feet and tight junctions in capillary endothelium (Correct answer)
- Ependymal cells lining ventricles
- Oligodendrocyte sheaths
Correct answer: Astrocyte end-feet and tight junctions in capillary endothelium
The blood-brain barrier is maintained by tight junctions between cerebral capillary endothelial cells, supported by astrocyte end-feet.
Question 3: Which vitamin is required for the synthesis of clotting factors II, VII, IX, and X?
- Vitamin C
- Vitamin D
- Vitamin K (Correct answer)
- Vitamin E
Correct answer: Vitamin K
Vitamin K is a cofactor for gamma-carboxylation of clotting factors II, VII, IX, and X, making them functionally active.
Question 4: The primary site of erythropoiesis in adults is the:
- Liver
- Spleen
- Yellow bone marrow
- Red bone marrow (Correct answer)
Correct answer: Red bone marrow
In adults, red blood cells are produced in the red bone marrow of flat and irregular bones such as the sternum, ribs, and pelvis.
Question 5: The Cori cycle describes the metabolic relationship between which two organs?
- Liver and adipose tissue
- Muscle and kidney
- Liver and skeletal muscle (Correct answer)
- Pancreas and liver
Correct answer: Liver and skeletal muscle
The Cori cycle involves lactate produced by anaerobic glycolysis in skeletal muscle being transported to the liver and converted back to glucose.
Question 6: Which cranial nerve is responsible for the motor innervation of the tongue?
- CN V (Trigeminal)
- CN IX (Glossopharyngeal)
- CN X (Vagus)
- CN XII (Hypoglossal) (Correct answer)
Correct answer: CN XII (Hypoglossal)
CN XII (Hypoglossal) provides motor innervation to all intrinsic and most extrinsic muscles of the tongue.
Question 7: Osteoclasts are derived from which precursor cell lineage?
- Osteoblasts
- Fibroblasts
- Monocyte/macrophage lineage (Correct answer)
- Chondrocytes
Correct answer: Monocyte/macrophage lineage
Osteoclasts are large multinucleated cells derived from the monocyte/macrophage hematopoietic lineage that resorb bone matrix.
BHS Anatomy and Physiology 4
Which muscle is the prime mover for elbow flexion when the forearm is supinated?