MDS PREP
Which hormone binding protein is increased during pregnancy?
1) Thyroxine binding globulin (TBG)
2) Thyroxine binding albumin
3) Thyroxine binding prealbumin
4) All of the above
Answer: 1) Thyroxine binding globulin (TBG) is increased during pregnancy, which is a major thyroid hormone binding protein in the plasma.
MCQ: The gastrocolic reflex is:
1) The contraction of the stomach triggered by the presence of food in the duodenum
2) The contraction of the small intestine triggered by the presence of food in the stomach
3) The contraction of the rectum triggered by the presence of food in the stomach
4) The contraction of the gallbladder triggered by the presence of food in the small intestine
The gastrocolic reflex is the contraction of the colon triggered by the presence of food in the stomach, facilitating bowel movements.
Which of the following inhibits gastric acid secretion?
1) Low pH in the stomach
2) High pH in the duodenum
3) Secretion of gastrin
4) Both A and B
Physiology
Answer: 4
Gastric acid secretion is inhibited by acidification of the stomach and duodenum. Low pH (acidity) in the stomach inhibits gastrin release from G cells, while high pH in the duodenum also contributes to the negative feedback mechanism that reduces acid secretion.
Which cells in the late distal tubule and cortical collecting tubules are responsible for potassium secretion?
1) Principal cells
2) Intercalated cells
3) Juxtaglomerular cells
4) Podocytes
Principal cells in the late distal tubule and cortical collecting tubules are responsible for potassium secretion, which is essential for maintaining electrolyte balance.
What is the function of the reticular formation in the regulation of sleep and wakefulness?
1) It initiates sleep
2) It maintains wakefulness
3) It is not involved in sleep-wake regulation
4) It initiates REM sleep
The reticular formation plays a crucial role in maintaining wakefulness by sending activating signals to the thalamus and cortex.
Which of the following is the primary active transport mechanism for calcium absorption in the intestine?
1) Vitamin D dependent calcium binding protein (calbindin)
2) Sodium-calcium exchanger (NCX)
3) Calcium-dependent ATPase
4) All of the above
Physiology
Answer: 4
Calcium is absorbed mainly in the duodenum and jejunum by an active transport mechanism regulated by 1,25 (OH)2 D3 (calcitriol). It is transported across the brush border of intestinal epithelial cells via TRPV6 channels and binds to calbindin. The absorbed calcium is then delivered to the basolateral membrane by calbindin, and from there it is transported into the bloodstream by either the sodium-calcium exchanger (NCX) or calcium-dependent ATPase.
Which of the following is NOT a primary bile acid synthesized in the liver from cholesterol?
1) Cholic acid
2) Chenodeoxycholic acid
3) Deoxycholic acid
4) Lithocholic acid
Deoxycholic acid is NOT a primary bile acid synthesized in the liver from cholesterol; it is a secondary bile acid formed from the bacterial action on primary bile acids in the intestine.
Which of the following structures is associated with the control of voluntary eye movement?
1) Occipital lobe
2) Temporal lobe
3) Frontal eye field
4) Parietal lobe
The frontal eye field, located in the dorsolateral part of the frontal lobe, is involved in the control of voluntary eye movement. It is part of the motor system and helps in the planning and execution of saccadic movements.