GMS 6440 Review Exam Questions And Answers

Our body secretes about 8L of intestinal juices into the GI tract daily, but only _________ mL of water is excreted in feces. - ANS 100 mL (the rest is reabsorbed by the digestive system) How many lobes are found in the lungs? - ANS There are 3 lobes in the right lung, while the smaller left lung has 2 lobes, making space in the chest cavity for the heart. Filtrate produced by the glomerulus of the nephron will flow through the nephron tubules in what order? - ANS Bowman's capsule -- proximal tubule -- loop of Henle -- distal tubule -- collecting duct. What chemical component of the plasma membrane prevents ions from readily and freely moving across the membrane? - ANS Lipids (phospholipids) Where is the concentration of [K+] greater: the ICF or the ECF? - ANS ICF; K+ is largely an intracellular ion. Across a cell's plasma membrane, movement of water is (passive/active) and (simple/facilitated). - ANS passive (by osmosis), facilitated (through a channel) Where is the concentration of [Na+] greater: ICF or ECF? - ANS ECF; Na+ is largely an extracellular ion. Describe secondary active transport of glucose. - ANS Glucose is moved into the cell, against its concentration gradient, by symport with Na+ (through the sodium-glucose cotransporter.) This is secondary active transport, and relies on the Na+ gradient being favorable due to actions of other ATPases. The movement of a charged electrolyte across the cell membrane is determined by ______________________, _______________________, and _______________. - ANS concentration gradient (or chemical potential) voltage (or electric potential) permeability Which ion and channel is primarily responsible for establishing a typical cell membrane's "resting" potential? - ANS K+, via the potassium "leak" channel True or False: Excessive extracellular acid (i.e., [H+] ) will raise the concentration of extracellular potassium ion concentration. - ANS True. H+/K+-exchange pumps uptake H+ into cells to preserve blood pH, causing hyperkalemia in plasma. Rhabdomyolysis, or muscle crush, can lead to cardiac muscle cell pathology as the result of _________________. - ANS excess extracellular K+ (hyperkalemia) True or False: The capillary wall is the main barrier between the intracellular and extracellular fluids. - ANS False; the cell wall is the ICF/ECF barrier. The capillary wall separates interstitium and blood plasma. True or False: To measure the volume of the entire extracellular fluid compartment, we use a substance that moves freely across the capillary but cannot enter the cell. - ANS True; An example is inulin. True or False: Water and small solutes move across the capillary wall by active transport. - ANS False: All movement across the capillary wall is passive, driven by hydrostatic and colloid osmotic (oncotic) pressures. True or False: The osmolality of the body fluids is greater when all the solutes are large. - ANS False: The total number of particles, irrespective of size, determines osmolality. True or False: All water movement in and out of cell is passive. - ANS True; water movement is driven by solute (osmotic) gradients across the cell wall. True or False: Eating a meal high in salt, without drinking any water will lead to an increase in both intracellular and extracellular fluid volume. - ANS False: This is a hypertonic expansion: Ingested NaCl stays extracellular, increasing the ECF osmolality, causing H2O to move OUT of cells to restore osmotic equilibrium. Decrease in ICFV, increase in ECFV. True or False: A pure water solution can safely be infused intravenously to a dehydrated person. - ANS False: Water will enter the surrounding cells causing swelling and lysis. The potassium released in to the extracellular fluid by cell lysis can be fatal. A 5% glucose solution is iso-osmotic to body fluids, so safe to infuse. After metabolism of the glucose this is equivalent to giving pure water. True or False: Receptors for peptide hormones are always on the inside (cytoplasm; nucleus) of target cells. - ANS False, they are found on the cell membrane / cell surface as peptides cannot diffuse across the membrane. G-protein coupled receptors (GPCR) are also known as ____________. - ANS 7TM (seven trans-membrane) receptors G_as proteins (stimulatory) couple to ______________, which converts ATP to cAMP. - ANS adenylyl cyclase G_ai proteins (inhibitory) cause inhibition of ____________ production. - ANS cAMP (cyclic adenosine mono-phosphate) True or False: Ionotropic receptors signal via G proteins. - ANS False, they allow passage of ions (Ca++, Na+) through a channel to stimulate signalling. __________ __________ receptors catalyze GTP into cGMP for signaling; one example is the atrial natriuretic peptide receptor. - ANS guanylyl cyclase True or Fasle: Receptors for Thyroid Hormone and steroids are always on the surface (plasma membrane) of target cells. - ANS False, these receptors are internal to the cell as these hormones pass freely through the membrane. Tyrosine kinase receptors are activated through ____________ : ligand binding causes the internal portion of the membrane proteins to come together, forming a two-unit structure. - ANS dimerization True or False: Glia are only present in the central nervous system. - ANS False, they are found in the peripheral nervous system as well. True or False: The nucleus of the solitary tract is found in the medulla oblongata. - ANS True True or False: The hypothalamus regulates both autonomic and endocrine function. - ANS True True or false: Afferent nerves transmit information from the central nervous system to the peripheral nervous system. - ANS False, those are efferent nerves. True or False: Activation of the parasympathetic nervous system constricts the airways. - ANS True. Sympathetic activation dilates the airways and increases ventilation; parasympathetic action opposes it. True or False: The cell bodies of postganglionic neurons are in the central nervous system. - ANS False; the ganglia lie outside the CNS, and so the preganglionic--postganglionic synapse occurs in the PNS. True or False: Acetylcholine acts on alpha and beta receptors. - ANS False, alpha and beta receptors are adrenergic (affected by NE/EPI), not cholinergic. The _________ ___________ releases epinephrine and norepinephrine into the blood stream. - ANS adrenal medulla