Human Physiology
In the small intestine, the majority of nutrient absorption occurs in the:
A
Duodenum
B
Jejunum
C
Ileum
D
All three equally
Correct Answer:
B. Jejunum
The jejunum is the primary site for nutrient absorption due to its extensive villi and optimal length for absorption process.
The normal pH of blood is maintained primarily by:
A
Proteins and phosphate buffers
B
Bicarbonate buffer system
C
Hemoglobin buffer system
D
All of the above
Correct Answer:
D. All of the above
Blood pH (7.35-7.45) is maintained by multiple buffer systems including bicarbonate, phosphate, and protein buffers working together.
Which of the following hormones is NOT produced by the anterior pituitary?
A
Growth hormone
B
ACTH
C
ADH
D
FSH
ADH (Antidiuretic hormone) is produced by the hypothalamus and stored/released by the posterior pituitary, not the anterior pituitary.
During inspiration, the diaphragm contracts and moves:
A
Upward
B
Downward
C
Laterally
D
Anteriorly
Correct Answer:
B. Downward
Diaphragm contraction flattens it and moves downward, increasing thoracic cavity volume and decreasing intra-pulmonary pressure.
A patient has difficulty in accommodation of the eye. Which lens condition is responsible?
A
Loss of elasticity of the lens
B
Increased corneal curvature
C
Reduced aqueous humor
D
Detached retina
Correct Answer:
A. Loss of elasticity of the lens
Presbyopia occurs due to loss of lens elasticity with age, reducing accommodation ability for near vision.
Which structure in the brain is responsible for maintaining body equilibrium and balance?
A
Cerebrum
B
Cerebellum
C
Medulla oblongata
D
Hypothalamus
Correct Answer:
B. Cerebellum
The cerebellum coordinates voluntary movements and maintains body balance through proprioceptive feedback.
The cardiac cycle duration in a normal adult is approximately:
A
0.4 seconds
B
0.8 seconds
C
1.2 seconds
D
1.6 seconds
Correct Answer:
B. 0.8 seconds
A complete cardiac cycle takes approximately 0.8 seconds at a heart rate of 72 beats per minute.
Which enzyme initiates protein digestion in the stomach?
A
Lipase
B
Pepsin
C
Trypsin
D
Amylase
Correct Answer:
B. Pepsin
Pepsin is a protease secreted by gastric glands that begins protein digestion in the acidic environment of the stomach.
The hormone that increases blood glucose concentration is:
A
Insulin
B
Glucagon
C
Thyroxine
D
Vasopressin
Correct Answer:
B. Glucagon
Glucagon, secreted by alpha cells of pancreatic islets, increases blood glucose through glycogenolysis and gluconeogenesis.
Which of the following is the primary function of the glomerulus in the nephron?
A
Ultrafiltration of blood
B
Reabsorption of glucose
C
Secretion of ammonia
D
Synthesis of urea
Correct Answer:
A. Ultrafiltration of blood
The glomerulus is a network of capillaries where ultrafiltration occurs, filtering small molecules like glucose, ions, and urea from blood into Bowman's capsule.
