MDS PREP
What hormone is secreted by the kidneys that stimulates red blood cell production?
1) Renin
2) Erythropoietin
3) Aldosterone
4) Cortisol
Erythropoietin is the hormone secreted by the kidneys that stimulates red blood cell production in response to low oxygen levels in the blood.
What is the primary function of the cholinergic system in the gastrointestinal tract?
1) Decreases peristalsis and relaxes sphincters
2) Increases peristalsis and relaxes sphincters
3) Increases peristalsis and constricts sphincters
4) Decreases peristalsis and constricts sphincters
The cholinergic system, acting via muscarinic receptors, increases peristalsis and relaxes the sphincters in the gastrointestinal tract to facilitate the movement of food and waste through the digestive system.
What is the function of the macula densa in the regulation of the nephron's function?
1) It secretes ADH to regulate water reabsorption.
2) It monitors sodium chloride concentration in the tubular fluid.
3) It produces erythropoietin to stimulate RBC production.
4) It is involved in the conversion of vitamin D to its active form.
The macula densa monitors sodium chloride concentration in the tubular fluid, playing a crucial role in regulating kidney function.
What is the transport maximum for glucose reabsorption in the kidneys?
1) 125 mg/min
2) 250 mg/min
3) 375 mg/min
4) 500 mg/min
The transport maximum for glucose reabsorption in the kidneys is about 375 mg/min, which indicates the maximum amount of glucose that can be reabsorbed before it appears in the urine.
Which hormone is primarily responsible for the conversion of 7-dehydrocholesterol to cholecalciferol in the skin?
1) Parathyroid hormone (PTH)
2) Vitamin D
3) Ultraviolet B (UV2) light
4) 25-hydroxyvitamin D3
Physiology
Answer: 3
The conversion of 7-dehydrocholesterol to cholecalciferol (vitamin D3) in the skin is initiated by the action of UVB light from sunlight, not by any specific hormone.
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.
The epithelial cells of the villi in the small intestine are responsible for:
1) Secreting gastric acid
2) Synthesizing bile
3) Final stage of digestion and nutrient absorption
4) All of the above
The epithelial cells of the villi in the small intestine contain various digestive enzymes and microvilli that increase the surface area for nutrient absorption. These cells are crucial for the final stages of digesting carbohydrates and proteins, as well as for the absorption of nutrients.
Which of the following statements about glomerular filtrate is true?
1) It contains high levels of proteins.
2) It is isotonic to plasma.
3) It is essentially protein-free.
4) It has a higher concentration of glucose than plasma.
Glomerular filtrate is essentially protein-free, allowing for the passage of water, electrolytes, and small molecules while retaining larger proteins in the bloodstream.