MDS PREP
What is the function of cholecystokinin (CCK) in the digestive system?
1) Stimulates the release of bile from the liver
2) Increases the secretion of water in the collecting tubules of the kidney
3) Relaxes the lower esophageal sphincter
4) Decreases the motility of the small intestine
Cholecystokinin (CCK) stimulates the release of bile from the liver and pancreatic enzymes, aiding in digestion.
Most of the pre ganglionic sympathetic fibres are
1 A fibres
2 B fibres
3 C Fibres
4 None of the above
Physiology
Answer: 2
- A fibres are myelinated fibres having fastest rate of conduction
Which hormone is primarily responsible for the gastric phase of gastric secretion?
1) Secretin
2) Gastrin
3) Cholecystokinin
4) GIP
E) VIP
Gastrin is the major hormone that stimulates the gastric phase of gastric secretion. It is released from G cells in the antral mucosa in response to food in the stomach, particularly proteins and amino acids, and to a lesser extent, to the presence of acid. Gastrin stimulates the parietal cells to secrete hydrochloric acid and intrinsic factor.
What is the primary role of estrogen during the follicular phase of the menstrual cycle?
1) Suppression of FSH secretion
2) Stimulation of follicular development
3) Preparation of the endometrium for implantation
4) Induction of the LH surge
During the follicular phase of the menstrual cycle, estrogen stimulates follicular development, promoting the maturation of ovarian follicles.
What is the function of the lateral nucleus of the hypothalamus?
1) It acts as the feeding center
2) It acts as the satiety center
3) It regulates the sympathetic nervous system
4) It controls the release of pituitary hormones
Answer: 1) The lateral nucleus of the hypothalamus is considered the feeding center, which stimulates appetite and food intake.
What is the significance of the ponto-genital occipital spikes seen in REM sleep?
1) They indicate deep sleep
2) They indicate the onset of dreaming
3) They are associated with eye movement
4) They are markers of REM sleep
Ponto-genital occipital spikes, or PGO waves, are characteristic of REM sleep and are thought to be associated with the onset of dreaming, as they often coincide with rapid eye movement and increased brain activity during this phase.
In the presence of which substance does vitamin B12 combine in the stomach to prevent its degradation by gastric acid?
1) Intrinsic factor
2) Pepsin
3) Gastric acid
4) Pancreatic amylase
Physiology
Answer: 1
Vitamin B12 combines with intrinsic factor to form a complex that is protected from degradation by gastric acid.
What is the threshold for phosphate excretion in the urine?
1) 0.10 mM
2) 0.50 mM
3) 1.00 mM
4) 2.00 mM
Physiology
Answer: 2
The threshold for phosphate excretion is when the plasma phosphate concentration reaches approximately 0.50 mM, causing some to be filtered into the urine.