NEET MDS Shorts
68993
Physiology
Answer: 1) Activation of glycogen phosphorylase by epinephrine
Explanation: Epinephrine acts on the beta-adrenergic receptors of liver and muscle cells, which activate protein kinase. This kinase then phosphorylates and activates glycogen phosphorylase, an enzyme that breaks down glycogen into glucose-1-phosphate, which is rapidly converted to glucose-6-phosphate for use in glycolysis or for release into the bloodstream to maintain glucose levels during stress.
52215
PhysiologyThe primary mechanism of sodium reabsorption in the distal convoluted tubule and collecting ducts is active transport with the sodium-potassium ATPase pump.
93344
Physiology
The stomach protects itself from the harsh acidic environment and its own digestive enzymes through the secretion of a thick layer of mucus by mucosal cells. This mucus barrier forms a physical and chemical barrier that shields the underlying tissue from the acid and pepsin. Additionally, the stomach lining has a high turnover rate and is continuously regenerated, and the enzymes in the gastric juice are inactive until they come into contact with food.
77210
Physiology
The enteric nervous system is the intrinsic nervous system of the gastrointestinal tract and is responsible for the regulation of digestion and other gastrointestinal functions. It can operate independently of the central nervous system and consists of a network of neurons and glial cells that are embedded within the wall of the gut, coordinating local reflexes and influencing the muscle and secretory activities of the digestive system.
48455
Physiology
The question contains an error. The terms autocrine, paracrine, endocrine, and synaptic are not types of action potential propagation. Instead, they describe different modes of hormonal or neuronal signaling. Action potentials are propagated along axons without any of these specific types of interactions.
95349
Physiology
Answer: 2) Secretion of epinephrine and norepinephrine
Explanation: 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.
97379
PhysiologyGlomerular filtrate is essentially protein-free, allowing for the passage of water, electrolytes, and small molecules while retaining larger proteins in the bloodstream.
39837
Physiology
Answer: 1) Induction of glucokinase
Explanation: Insulin enhances glucose uptake in the liver by inducing the synthesis of glucokinase, an enzyme that converts glucose into glucose-6-phosphate. This "glucose trapping" mechanism keeps intracellular glucose levels low and promotes further glucose entry into the cell.
13138
PhysiologyWhen the corpus luteum regresses during the menstrual cycle, it stops secreting estrogen and progesterone, leading to the shedding of the uterine lining.
45038
PhysiologyThe main stimulation for production of A.D.H. is Decrease in blood volume - A.D.H. secretion increases during osmotic diuresis