CMI Biomedical Science & Human Anatomy 2 — Questions and Answers
Question 1: Which layer of the epidermis contains keratinocytes undergoing mitosis?
- Stratum corneum
- Stratum granulosum
- Stratum basale (Correct answer)
- Stratum spinosum
Correct answer: Stratum basale
The stratum basale is the deepest epidermal layer where mitotic division of keratinocytes occurs to replenish cells lost from the surface.
Question 2: Which cranial nerve innervates the muscles of facial expression?
- Trigeminal nerve (CN V)
- Facial nerve (CN VII) (Correct answer)
- Glossopharyngeal nerve (CN IX)
- Vagus nerve (CN X)
Correct answer: Facial nerve (CN VII)
The facial nerve (CN VII) provides motor innervation to the muscles of facial expression, including the orbicularis oculi and zygomaticus.
Question 3: In the nephron, where does the majority of glucose reabsorption occur?
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
- Proximal convoluted tubule (Correct answer)
Correct answer: Proximal convoluted tubule
Approximately 99% of filtered glucose is reabsorbed in the proximal convoluted tubule via sodium-glucose cotransporters (SGLT2).
Question 4: The acetabulum is a socket found in which bone of the pelvis?
- Sacrum
- Ischium only
- Os coxae (hip bone) (Correct answer)
- Femur
Correct answer: Os coxae (hip bone)
The acetabulum is a cup-shaped socket formed by the fusion of the ilium, ischium, and pubis — together called the os coxae — that articulates with the femoral head.
Question 5: Which type of cartilage forms the intervertebral discs?
- Hyaline cartilage
- Elastic cartilage
- Fibrocartilage (Correct answer)
- Calcified cartilage
Correct answer: Fibrocartilage
Fibrocartilage, which contains dense collagen bundles, forms the annulus fibrosus of intervertebral discs, providing tensile strength and shock absorption.
Question 6: Which structure divides the thoracic cavity from the abdominal cavity?
- Pleura
- Pericardium
- Diaphragm (Correct answer)
- Mediastinum
Correct answer: Diaphragm
The diaphragm is the dome-shaped musculotendinous partition that separates the thoracic and abdominal cavities and is the primary muscle of respiration.
Question 7: What is the primary function of the sinoatrial (SA) node in the heart?
- Delay conduction between atria and ventricles
- Generate the initial electrical impulse for cardiac rhythm (Correct answer)
- Conduct impulses through ventricular walls
- Control heart rate via parasympathetic signals only
Correct answer: Generate the initial electrical impulse for cardiac rhythm
The SA node is the heart's pacemaker, spontaneously generating electrical impulses that initiate each heartbeat and set the sinus rhythm.
CMI Biomedical Science & Human Anatomy 2
Which layer of the epidermis contains keratinocytes undergoing mitosis?