MDS PREP
What is the primary function of the somatic sensory area of the parietal lobe?
1) Auditory perception
2) Visual perception
3) Somatic sensation interpretation
4) Olfactory perception
The somatic sensory area of the parietal lobe, particularly Brodmann's areas 3, 1, and 2, is involved in the interpretation of tactile, proprioceptive, and other sensory information from the body.
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 is the primary effect of excitatory postsynaptic potentials (EPSPs) on the excitability of a neuron?
1) Depolarization
2) Hyperpolarization
3) No change in excitability
4) Initiation of an action potential
Answer: 1) DepolarizationExplanation: EPSPs occur when the neurotransmitter binds to postsynaptic receptors that open sodium channels, allowing sodium ions to flow into the neuron and causing the membrane to depolarize. This increases the excitability of the neuron, bringing the membrane potential closer to the threshold for action potential firing.
What is the significance of the transport maximum for substances like glucose and phosphate?
1) It indicates the maximum amount that can be filtered by the glomerulus
2) It represents the maximum amount that can be actively reabsorbed by the tubules
3) It is the point at which the substance begins to be excreted in the urine
4) It is the point at which the substance becomes toxic to the body
Physiology
Answer: 2
Transport maximum indicates the maximum rate at which an active transport system can reabsorb a substance from the glomerular filtrate.
Which of the following is NOT a secondary bile acid?
1) Cholic acid
2) Deoxycholic acid
3) Lithocholic acid
4) Chenodeoxycholic acid
Physiology
Answer: 1
Cholic acid is a primary bile acid, while deoxycholic acid and lithocholic acid are secondary bile acids formed by bacterial action in the colon.
Which of the following is the primary active transport mechanism for calcium absorption in the intestine?
1) Vitamin D dependent calcium binding protein (calbindin)
2) Sodium-calcium exchanger (NCX)
3) Calcium-dependent ATPase
4) All of the above
The primary active transport mechanism for calcium absorption in the intestine involves all of the above: vitamin D dependent calcium binding protein (calbindin), sodium-calcium exchanger (NCX), and calcium-dependent ATPase.
What is the primary component of the glomerular filtration barrier?
1) Glomerular capillary endothelium
2) Basement membrane
3) Bowman's capsule
4) Podocytes
E) All of the above
The glomerular filtration barrier is composed of the glomerular capillary endothelium, the basement membrane, and the podocytes (Bowman's visceral epithelium). These three layers work together to filter blood and form the glomerular filtrate, which then enters the renal tubules.
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
The primary function of the epididymis in the male reproductive system is the storage and maturation of sperm, allowing them to gain motility and the ability to fertilize an egg.