MDS PREP
What is the significance of the transport maximum for substances like glucose and phosphate?
1) It indicates the maximum amount that can be filtered by the glomerulus
2) It represents the maximum amount that can be actively reabsorbed by the tubules
3) It is the point at which the substance begins to be excreted in the urine
4) It is the point at which the substance becomes toxic to the body
The transport maximum for substances like glucose and phosphate represents the maximum amount that can be actively reabsorbed by the tubules before reaching saturation and being excreted in urine.
What primarily determines the Glomerular Filtration Rate (GFR)?
1) Blood volume
2) Net filtration pressure and Kf
3) Renal blood flow
4) Urine output
The Glomerular Filtration Rate (GFR) is primarily determined by net filtration pressure and the glomerular capillary filtration coefficient (Kf), which reflects the permeability of the glomerular membrane.
What is the role of the area postrema in the regulation of food intake?
1) It senses the presence of food in the stomach
2) It detects the nutritional content of food
3) It is involved in the detection of toxins and the initiation of vomiting
4) It directly stimulates the release of hunger hormones
The area postrema is part of the chemoreceptive trigger zone and detects the presence of toxins in the bloodstream, leading to the initiation of vomiting as a protective mechanism against the ingestion of harmful substances.
What is the effect of fluorescent lighting on detecting scleral icterus?
1) It enhances the visibility of scleral icterus.
2) It does not affect the visibility of scleral icterus.
3) It makes it more difficult to detect scleral icterus.
4) It causes a false-positive result for scleral icterus.
Fluorescent lighting enhances the visibility of scleral icterus, making it easier to detect jaundice.
What is the typical pH of gastric chyme when it enters the duodenum?
1) 1.0-2.0 (very acidic)
2) 2.0-4.0 (slightly acidic)
3) 4.0-6.0 (weakly acidic)
4) 6.0-8.0 (slightly alkaline)
E) 8.0-10.0 (alkaline)
Gastric chyme, which is the mixture of food and gastric juice, is highly acidic due to the presence of hydrochloric acid secreted by parietal cells. The pH typically ranges from 1.0 to 2.0 when it enters the duodenum. This acidity helps to denature proteins and provides the optimal environment for pepsin activity. Once in the duodenum, the chyme is neutralized by the secretion of bicarbonate from the pancreas and bile from the liver.
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 role of the cholinergic system in the regulation of urinary bladder function?
1) Contraction of the detrusor muscle and relaxation of the trigone
2) Relaxation of the detrusor muscle and contraction of the trigone
3) Contraction of the urethral sphincter
4) Contraction of the urethral sphincter and relaxation of the detrusor muscle
The parasympathetic nervous system, which is cholinergic, stimulates the detrusor muscle of the urinary bladder to contract and the trigone muscle to relax, facilitating micturition (urination). This is mediated by the activation of muscarinic M3 receptors.
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