MDS PREP
What sleep stage is characterized by beta-wave activity on EEG, dreaming, and generalized muscular atonia?
1) Stage 1 NREM
2) Stage 2 NREM
3) REM sleep
4) Stage 3 NREM
REM sleep is characterized by beta-wave activity, dreaming, and muscular atonia, which is a state of almost complete paralysis except for the muscles controlling eye movement, respiration, and other involuntary processes.
What is the primary neurotransmitter of the sympathetic nervous system?
1) Acetylcholine
2) Norepinephrine
3) Dopamine
4) Epinephrine
The sympathetic nervous system primarily uses norepinephrine (also known as noradrenaline) as its neurotransmitter. It is released from the synaptic terminals of postganglionic sympathetic fibers and acts on adrenergic receptors, which are found on various target cells throughout the body. This neurotransmitter is essential for the body's "fight or flight" response, contributing to increased heart rate, dilated pupils, and other physiological changes associated with stress or emergency situations.
What is the primary function of the Adrenal Medulla in the fight-or-flight response?
1) Secretion of cortisol
2) Secretion of epinephrine and norepinephrine
3) Secretion of aldosterone
4) Secretion of thyroxine
Answer: 2) Secretion of epinephrine and norepinephrineExplanation: The Adrenal Medulla is part of the sympathetic nervous system and produces the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline) in response to stress or danger. These hormones are crucial for the fight-or-flight response, which prepares the body for immediate action by increasing heart rate, blood pressure, and diverting blood flow to the muscles and brain.
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.
The glomerular filtration rate (GFR) is determined by which two factors?
1) Blood pressure and urine osmolarity
2) Blood flow rate and tubular reabsorption
3) Net filtration pressure and glomerular capillary filtration coefficient (Kf)
4) Hormonal levels and urine volume
The glomerular filtration rate (GFR) is determined by net filtration pressure and the glomerular capillary filtration coefficient (Kf), which are critical for kidney function.
The rate of gastric emptying is influenced by:
1) The quantity and type of food ingested
2) Distension of the duodenum
3) Gastric hormones like gastrin
4) All of the above
The rate of gastric emptying is influenced by the presence of food in the stomach, the type of food (carbohydrates, proteins, and fats), the distension of the duodenum, and the hormone gastrin, which can increase the rate of emptying.
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 primary effect of thyroid hormones on cardiac output?
1) Decrease in heart rate and stroke volume
2) Increase in heart rate and stroke volume
3) Decrease in heart rate and decrease in stroke volume
4) Increase in heart rate and increase in stroke volume
Answer: 4) Increase in heart rate and increase in stroke volumeExplanation: Thyroid hormones, such as thyroxine (T4) and triiodothyronine (T3), enhance the effects of catecholamines on the cardiovascular system, leading to increased heart rate and stroke volume. This results in a higher cardiac output, which is essential for meeting the increased metabolic demands during stress or exercise.