MDS PREP
What is the primary function of the epididymis in the male reproductive system?
1) Storage and maturation of sperm
2) Secretion of androgens
3) Formation of the spermatozoa
4) Fusion of gametes during fertilization
Physiology
Answer: 1
The epididymis is a coiled tubular structure located behind the testis. Its primary function is to store and mature sperm cells, making them fully motile and capable of fertilization.
What is the role of the corpus luteum in the second half of the menstrual cycle?
1) It secrets FSH
2) It secrets LH
3) It secrets estrogen and progesterone
4) It secrets inhibin
The corpus luteum secretes estrogen and progesterone during the second half of the menstrual cycle, which are essential for maintaining the uterine lining.
What happens when the corpus luteum regresses during the menstrual cycle?
1) It secrets more estrogen and progesterone
2) It stops secreting estrogen and progesterone
3) It starts secreting FSH and LH
4) It causes an increase in the thickness of the endometrium
Physiology
Answer: 2
The regression of the corpus luteum leads to a sharp decline in estrogen and progesterone levels, which in turn causes the endometrium to shed and results in menstrual bleeding.
Which of the following statements about the sensory neurons and their pathways in the spinal cord is correct?
1) All sensory neurons synapse with motor neurons in the ventral horn to form spinal reflex arcs
2) Only pain and temperature sensations ascend to the brainstem for conscious perception
3) The axons of sensory neurons from the dorsal root ganglion may directly synapse with motor neurons or ascend to the brain
4) Sensory neurons only project to the reticular formation and thalamus for nonspecific arousal
The axons of sensory neurons from the dorsal root ganglion can follow three routes: forming spinal reflexes by synapsing with motor neurons, ascending to the brainstem for conscious perception, or relaying through the reticular formation and thalamus for general arousal.
What is the primary type of receptor involved in the sympathetic nervous system's response at the neuromuscular junction?
1) Muscarinic receptors
2) Nicotinic receptors
3) Alpha-1 receptors
4) Beta-2 receptors
Answer: 2) The primary type of receptor involved in the sympathetic nervous system's response at the neuromuscular junction is the nicotinic receptor, which is an intrinsic ligand-gated ion channel.
What happens when the estrogen level crosses a certain threshold during the menstrual cycle?
1) It inhibits the release of LH and FSH
2) It stimulates the release of LH and FSH
3) It has no effect on pituitary hormone secretion
4) It triggers ovulation
When estrogen levels cross a certain threshold during the menstrual cycle, it triggers ovulation by stimulating the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
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.
What is the normal ratio of glycine to taurine conjugates of bile acids in the bile?
1) 1:1
2) 2:1
3) 3:1
4) 4:1
Physiology
Answer: 3
The ratio of glycine to taurine conjugates of bile acids is normally 3:1.