MDS PREP
Which of the following statements is true about the regulation of the sympathetic nervous system?
1) The sympathetic nervous system is primarily regulated by the parasympathetic nervous system.
2) The sympathetic nervous system is mainly controlled by the hypothalamus.
3) The sympathetic nervous system is regulated by the spinal cord through the sympathetic chain ganglia.
4) The sympathetic nervous system is primarily regulated by the sympathetic chain ganglia.
Answer: 3) The sympathetic nervous system is regulated by the spinal cord through the sympathetic chain ganglia, which receive input from the hypothalamus and other higher centers.
What is the transport maximum for phosphate reabsorption in the kidneys?
1) 0.10 mM/min
2) 0.50 mM/min
3) 1.00 mM/min
4) 2.00 mM/min
Physiology
Answer: 1
The transport maximum for phosphate is 0.10 mM/min, indicating the maximum rate at which it can be reabsorbed by the renal tubules.
Which of the following is NOT a hormone produced by the kidneys?
1) Renin
2) Erythropoietin
3) Aldosterone
4) 1,25 Dihydrocholecalciferol
Aldosterone is NOT a hormone produced by the kidneys; it is produced by the adrenal glands and acts on the kidneys to regulate sodium and potassium balance.
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 primary mechanism by which thyroid hormones increase metabolic rate?
1) Stimulation of the sympathetic nervous system
2) Increased expression of uncoupling proteins
3) Increased activity of the sodium-potassium ATPase pump
4) Stimulation of mitochondrial oxidative phosphorylation
Answer: 4) Stimulation of mitochondrial oxidative phosphorylationExplanation: Thyroid hormones, particularly T3, increase metabolic rate by enhancing the activity of mitochondrial oxidative phosphorylation. This leads to increased ATP production and overall cellular energy metabolism.
In which part of the nephron does the majority of glucose reabsorption occur?
1) Loop of Henle
2) Proximal convoluted tubule
3) Distal convoluted tubule
4) Collecting duct
The majority of glucose reabsorption occurs in the proximal convoluted tubule, where glucose is actively transported back into the bloodstream.
What is the function of the pineal gland in regulating circadian rhythms?
1) It produces melatonin in response to light exposure
2) It produces cortisol to maintain wakefulness
3) It regulates body temperature
4) It is not involved in circadian rhythms
The pineal gland produces melatonin in response to light exposure, helping to regulate circadian rhythms and sleep-wake cycles.
What is the role of leptin in the regulation of food intake?
1) It stimulates food intake
2) It inhibits food intake
3) It has no effect on food intake
4) It increases the absorption of nutrients in the intestine
Physiology
Answer: 2
Leptin is a hormone secreted by adipose tissue that acts on the hypothalamus to inhibit food intake and increase energy expenditure. It plays a key role in regulating body weight and metabolism by signaling satiety and modulating the sensation of hunger and fullness.