GMS 6440 Quiz Review Questions And Answers

Cardiac muscle contraction is considered to be voluntary movement. - ANS False; it moves involuntarily In the gastrointestinal tract, smooth muscle is enriched. - ANS True In our body, approximately 8 liters of intestinal juices are secreted into the GI tract daily, but only 100 ml of water is secreted into the feces. - ANS True Normal movement of blood flow in the heart is: left atrium-left ventricle-lung-right atrium-right ventricle. - ANS False; Right atrium-right ventricle-lung-left atrium-left ventricle Normally, humans have 2 lobes in the right lung and 3 lobes in the left lung. - ANS False; 3 lobes in the right lung and 2 lobes in the left lung. In the lung, gas exchange occurs mostly at the alveoli. - ANS True The urinary system is normally composed of two kidneys, two ureters and two bladders. - ANS False; Two kidneys, two ureters and one bladder. Filtered wastes from the glomerulus will move in the following order: Bowman's capsule-proximal tubule-distal tubule-loop of Henle-collecting duct. - ANS False; Bowman's capsule-proximal tubule- loop of Henle-distal tubule-collecting duct. Both endocrine and nervous systems play important roles in controlling the activities of many different organ systems to maintain homeostasis. - ANS True Specificity of hormone action in the target cells is determined by receptors. - ANS True The area of nerve axon not wrapped by myelin sheath (non-myelinated area) is called nodes of Ranvier where action potential is insulated. - ANS False; Myelin sheath insulates action potential. Action potential propagates faster by skipping myelinated axon, and jumping from nodes of Ranvier to another node. 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: - ANS Cytoplasm Across a cell's plasma membrane, movement of water is _______________. - ANS passive through a channel Where is the concentration of [Na+] greater: - ANS in the extracellular fluid For a neutrally charged molecule, "Active" transport means that the molecules move across a membrane: - ANS from low concentration to high concentration What molecule is the source of energy for primary active transport to occur? - ANS ATP (adenosine triphosphate) There is only one type of channel in cell membranes. - ANS False; Ligand-gated, Voltage-gated, Leak, Stretch-activated Regarding primary active transport, solutes move from a compartment of low concentration to a compartment of high concentration. - ANS True Regarding secondary active transport of glucose, the movement of glucose is from a compartment of high concentration to a compartment of low concentration. - ANS False; Low to High All transport through membrane channels is classified as "Active" transport. - ANS False; can be passive or active Electrolytes are pumped and leak across cell membranes simultaneously but independently. - ANS True At what point in time does the electrochemical equilibrium potential exist? - ANS At equilibrium What is a major factor that regulates an electrolyte's electrochemical equilibrium potential across a cell membrane? - ANS Concentration (chemical) gradient The electrochemical equilibrium potential for a single highly permeant ion species is controlled by the concentration gradient. - ANS True Movement of a charged electrolyte is determined by the major forces of voltage plus chemical concentration gradients - ANS True The cellular K+ Electrochemical Equilibrium Potential is regulated by concentration differences across plasma membranes. - ANS True Which of these ion choices is primarily responsible for establishing a typical cell membrane's "resting" potential? - ANS K+ Excessive extracellular acid (i.e., [H+] ) will raise the concentration of extracellular potassium ion concentration. - ANS True Cell Membrane Potential is controlled by the relative degree of ion permeability as well as ion concentration gradients existing across a cell's plasma membrane. - ANS True Rhabdomyolysis can lead to cardiac muscle cell pathology as the result of creating a condition of hyperkalemia (excessive K+ concentration in the plasma). - ANS True A normal lean person consists of ~ 95% water. - ANS False; ~ 60% water. Most of the sodium in the body is inside the cells. - ANS False; It is extracellular. The capillary is the main barrier between the intracellular and extracellular fluids. - ANS False; The cell wall (plasma membrane separates intracellular and extracellular fluid. The capillary separates the interstitium and the plasma, both sub- compartments of the extracellular fluid. 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. 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. 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. All water movement in and out of cell is passive. - ANS True; water movement is driven by solute (osmotic) gradients across the cell wall. Sodium (Na) is effectively impermeable at the cell wall. - ANS True: Any Na that does enter the cell will be immediately removed by the Sodium potassium ATPase in the cell wall. 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: Ingest NaCl stays extracellular, increases the ECF osmolality, H2O moves OUT of cells to restore osmotic equilibrium. Decrease in ICFV, increase in ECFV. 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. Hormones produce physiological actions by binding to receptors at their target cells/tissues. - ANS True There are specific receptors for each hormone. - ANS True Receptors for peptide hormones are always on the inside (cytoplasm; nucleus) of target cells. - ANS False; Outside (cell surface) of target cells GPCR are also known as seven trans-membrane (7TM) receptors. - ANS True Gaq proteins couple to adenylyl cyclase. - ANS False; GPCR Activation of ionotropic receptors results in an ion (Ca2+; Na+) moving into the target cell through a channel in the receptor. - ANS True