PNB 3255 Key Mandatory Questions and Answers 2024

The motor activity of the muscularis externa is controlled by the - myenteric plexus Which of the following are true regarding the secretion of HCl? (choose all that apply) a.) The H, K ATPase, also known as proten pump is present on the apical membrane of the parietnal cells. b.) As a by-product of the HCl secretion, HCO3- is transported out of the cell from the basolateral side of the cell. This can cause a alkaline tide (pH increase in plasma) immediately after a meal. c.) Na, K ATPases are expressed on the apical membrane of the pariental cells. They are responsible for establishing the concentration gradient for Na and K. d.) In parietal cells, H+ and Cl- are transported together to the lumen of the stomach. - a. & b. are both correct regarding the secretion of HCl A drug that blocks the fusion of tubulovesicular membrane and intracellular canaliculus in parietal cells would result in: - a decreased somatostatin production. (this question asks you to predict what will happen if HCl secretion is reduced) Hydrochloric acid secretion increases when _______ binds to its receptor and induces an elevation of intracellular __________. - Hydrochloric acid secretion increases when [ ACh ] binds to its receptor and induces and elevation of intracellular [ Ca2+ ]. **ACh, gastrin and histamine have a synergerstic effect on increasing HCl secretion. Both ACh (through M3 receptor) and gastrin (through CCK-B receptor) achieve this effect by increasing intracellular Ca. Histamine uses a different route (through H2 receptor) which increases intracellular cAMP. Which of the following suggestions will help alleviate heart burn? a.) Inject ACh agonist into the LES b.) Consume a larger meal c.) Lie down after meal d.) Increase alcohol consumption e.) Inject VIP agonist into the LES - a.) inject ACh agonist into the LES **Agonist can bind to a receptor and activates the receptor to produce a similar biological response. ACh generally plays an excitatory effect on the smooth muscle. VIP plays an inhibitory effect which relaxes the smooth muscle. Neurotransmitters that stimulate GI smooth muscle contractions include : a.) NO. b.) Substance P. c.) vasoactive intestinal polypeptide (VIP) d.) NO and VIP - b.) Substance P. Lacteals: a.) increase the surface area of the mucosa of the small intestine. b.) carry products of digestion that will not pass through the walls of blood capillaries. c.) produce new cells for the mucosa of the small intestine. d.) secrete digestive enzymes. e.) produce hormones. - b.) carry products of digestion that will NOT pass through the walls of blood capillaries In response to the hormone secretin, the pancreas secretes a fluid: a.) rich in bile. b.) rich in bicarbonate. c.) that contains only amylase. d.) that contains only proteases. e.) rich in enzymes. - b.) rich in bicarbonate Which of the following symptoms would you expect to observe in liver cirrhosis? (Choose all that apply.) a.) portal hypertension