MDS PREP
Which part of the autonomic nervous system is responsible for the regulation of the visceral organs during rest and digestion?
1) Sympathetic nervous system
2) Parasympathetic nervous system
3) Enteric nervous system
4) Sensory nervous system
The parasympathetic nervous system is involved in the regulation of the body's rest and digest functions. It operates to conserve energy and restore the body to a state of equilibrium. It acts on various visceral organs, such as the heart, gastrointestinal tract, and bladder, to slow down the heart rate, increase glandular secretions, and promote peristalsis for food assimilation.
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.
What is the effect of stimulating the cholinergic system in the male reproductive system?
1) Decreased testosterone secretion
2) Decreased penile erection
3) Increased testosterone secretion
4) Increased penile erection
Stimulation of the cholinergic system can lead to increased penile erection due to the vasodilation of blood vessels in the penis, allowing for greater blood flow and engorgement of the corpora cavernosa.
The reticular formation gives rise to which of the following extrapyramidal tracts?
1) Corticospinal tract
2) Reticulospinal tract
3) Vestibulospinal tract
4) Rubrospinal tract
E. Tectospinal tract
The reticulospinal tract arises from neurons in the reticular formation of the brainstem and projects to the spinal cord. It influences both voluntary and involuntary motor activities, modulating the excitability of motor neurons. The corticospinal tract arises from the cerebral cortex, the vestibulospinal tract from the vestibular nuclei, the rubrospinal tract from the red nucleus, and the tectospinal tract from the superior colliculus.
What is the primary function of vitamin D in the body?
1) Blood clotting
2) Bone formation and maintenance
3) Vision
4) Immune system function
Physiology
Answer: 2
Vitamin D is essential for the absorption of calcium and phosphorus from the diet, which are critical for bone formation and maintenance. It also plays roles in muscle function and immune system regulation, but its primary function is in the skeletal system.
What is the primary function of the macula densa?
1) Filtration of blood
2) Regulation of glomerular filtration rate
3) Secretion of renin
4) Reabsorption of glucose
The primary function of the macula densa is to regulate glomerular filtration rate by sensing sodium chloride concentration in the tubular fluid.
What is the function of the reticular formation in the regulation of sleep and wakefulness?
1) It initiates sleep
2) It maintains wakefulness
3) It is not involved in sleep-wake regulation
4) It initiates REM sleep
The reticular formation plays a crucial role in maintaining wakefulness by sending activating signals to the thalamus and cortex.
What is the primary action of endorphins on the body?
1) Inhibition of pain
2) Stimulation of growth
3) Regulation of mood and emotions
4) Increased blood pressure
E. Regulation of sleep-wake cycle
Endorphins, particularly ?-endorphin, are opioid peptides that act as natural painkillers. They are released during stress and pain and bind to opioid receptors in the brain and spinal cord to inhibit the transmission of pain signals. While they do have secondary effects on mood and stress response, their primary function is pain inhibition.