E109 FINAL EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026

E109 FINAL EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026 Why does it require energy to transport glucose across a digestive epithelial cell? - Answers The concentration of glucose is greater within the cell than in the gut lumen. The sciatic nerve includes neurons that run from the lower back to the foot. Myelination in these cells is important for all of the following reasons EXCEPT: - Answers Myelination ensures that the action potential travels in one direction only. It is possible for the ion permeability of a membrane to change if the membrane is placed in tension - Answers True Select all of the following TRUE statements. - Answers All connective tissue includes cells. Ground substance may be a liquid. How do epithelial cells transport water? - Answers By creating a favorable difference in solute concentration. Which of the following actions would serve to depolarize the membrane of a neuron? - Answers inhibiting the Na+/K+ pump. Increasing the extracellular [Na+]. Which of the following does not play a role at chemical synapse ? - Answers Voltage-gated Cl- channels. This figure illustrates an electrophysiological recording of the membrane potential of an axon.When is the cell hyperpolarized? - Answers Time iv. Which of the following statements are true about neurons? - Answers The dendrites can integrate stimuli from inhibitory and excitatory synapses. The axon hillock serves as the spike-initiating zone because of the presence of voltage-gated channels. Is the distance between the chemical synapse and axon hillock important for whether an axon potential is generated? - Answers Yes, changes in Vm in the dendrites depend on diffusion, which varies with distance. How would the equilibrium potential for Potassium (EK+) change if its concentration of that ion increased outside of a cell? - Answers It would increase. Which of the following is not true about an equilibrium potential? - Answers It is the same for all types of ions. It varies with the valence (i.e. charge) of an ion. It indicates the rate of active transport. Why does a second stimulus early in the relative refractory period have to be stronger to initiate a an action potential? - Answers It is because the membrane is hyperpolarized. Which of the following tissues are not excitable ? - Answers Blood & Adipose. This figure illustrates an electrophysiological recording of the membrane potential of an axon.During depolarization, what best accounts for the change in slope in Vm as the membrane reaches threshold? - Answers Na+ permeability changes What is not true about the Nerst equation? - Answers It calculates the membrane potential for ions of different permeability. You Answered Multiple types of Connective tissue include collagen fibers, which provide stiffness and elasticity. [ Select ] ["Muscle", "Connective", "Nervous", "Epithelial"] tissue is largely composed of extracellular components, such as ground substance, whereas transport [ Select ] ["Muscle", "Epithelial", "Connective", "Nervous"] tissue functions by transporting molecules through cells. - Answers 1. Connective 2. Connective 3. Epithelial Match the following characteristics to either Carrier, Channel membrane proteins, or both. Change confirmation Allow ions to leak Transmembrane protein - Answers 1. Carrier Proteins 2. Channel Proteins 3. Both Use the drop down menu to correctly describe the level of integration in the following sentence. The musculoskeletal [ Select ] ["Cells", "Tissues", "System", "Molecules", "Organs"] consists of [ Select ] ["Systems", "Tissues", "Molecules", "Organs", "Cells"] , including the bones and muscles. Bones and muscles are bound by connective [ Select ] ["Systems", "Tissues", "Organs", "Molecules", "Cells"] , which are largely comprised of collagen [ Select ] ["Organs", "Cells", "Tissues", "Systems", "Molecules"] . - Answers 1. System 2. Organs 3. Tissues 4.Molecules Match each properties/feature on that left with a particular ion channel on the right. Excitatory synapse. Inactivation gate. Drives depolarization in the axon. Drives repolarization in the axon. Inhibitory synapse. - Answers 1. Ligand-gated Na+ channel 2. Voltage gated Na+ channel 3.Voltage-gated Na+ channel 4.Voltage-gated K+ channel 5.Ligand-gated Cl- channel The below graphs show the membrane potential of individual synapses on a dendrite (red and blue curves), as well as the overall membrane potential of the cell body (black, dashed curve). Choose the graph(s) that illustrate temporal and/or spatial summation in a neuron. - Answers 1. 2 peaks near each other red and blue line cross 2. 2 peaks near eachother red line has 2 peaks blue line is straight and constant. When a stimulating electrode placed in the middle of an axon depolarizes the membrane, explain what happens and why. The action potential(s) propagate [ Select ] ["toward the axon terminal.", "toward both the axon terminal and cell body.", "toward the cell body."] . The [ Select ] ["Ca2+", "K+", "Na+"] ions that depolarize the membrane diffuse [ Select ] ["toward the cell body", "in all directions", "toward the terminal"] and drive [ Select ] ["Na+", "K+", "both K+ and Na+", "Ca2+"] voltage-gated channels to threshold. The action potential(s) can activate any portion of the membrane that is at its resting membrane potential. . - Answers 1. toward both the axon terminal and cell body. 2.Na+ 3. in all directions 4. both K+ and Na+ 5. at its resting membrane potential. Explain the conditions where the membrane potential achieves a membrane potential of +60 mV. Permeability to Na+. Permeability to K+. Permeability to Cl-. - Answers 1. High 2. Zero 3. Zero Your blood in dissolved in proteins but the intersitial space around your capillaries is devoid of proteins. The capillary walls are thin and permeable to water. If blood pressure were negiligble, what would you predict about the exchange of water between the blood and intersitiual fluid? - Answers Water should move from the interstitial fluid to the blood. This figure illustrates an electrophysiological experiment with measurements of the concentration differences on the inside (in gray) and outside (in white) of a neuron.Imagine that this cell membrane became permeable to chloride ions and impermeable to all other ions. What reading would you expect the voltmeter to read once it settles on a value? - Answers -86 mV Imagine the rate of diffusion for a molecule that fluxes across a 1 mm x 1 mm area of membrane is 10 Moles/second and the membrane has a thickness of 25 nm. What rate of diffusion (in Moles/second) would you predict if the molecular size were to increase by a factor of 10? - Answers Between 0.99 and 1.01 By what factor would the rate of diffusion change if membrane thickness increased by a factor of 5? - Answers Between 0.19 and 0.21 Select all of the following TRUE statements. - Answers Ground substance may be a liquid. All connective tissue includes cells. Choose the level(s) of biological organization that pertain to physiology, in this course. - Answers molecules tissues Which of the following are types of epithelia? - Answers Secretory Protective Exchange Ciliated Imagine an exercising muscle cell that requires a constant supply of oxygen to avoid fatigue. At which of the following distances from a capillary would you predict these muscle cells to have sufficient oxygen delivery? - Answers 20 nm 2 nm Which of the following factors increase the rate of diffusion across a membrane? - Answers Increasing the solute concentration difference across the membrane Increasing membrane permeability Increasing the membrane area Increases in which of the following increase the rate of chemical diffusion? - Answers Temperature Channel proteins are capable of active transport. - Answers False What proteins bind epithelial cells together to provide a strong membrane and chemical barrier? - Answers Desmosomes Tight junctions What is the most important reason for why it requires energy to transport glucose across the apical surface of a digestive epithelial cell? - Answers The concentration of glucose is greater within the cell than in the gut lumen. Choose the correct order of events in the myosin cycle. 1. ATP is hydrolyzed by the myosin head. 2. 3. 4. 5. 6. - Answers 2. myosin creates a cross-bridge with a G-actin binding site. 3. inorganic phosphate is released. 4. myosin pulls on the thin filament. 5. ADP is released. 6. myosin binds to ATP and releases from G-actin. A contraction that generates constant force and moves a load is known as [ Select ] ] , whereas one that generates force without movement is known as [ Select ] - Answers isotonic, isometric If Muscle A were half the width of Muscle B, by what factor is the force generated by A different from B, assuming a circular cross-section for the muscles? - Answers .25 The curve in iii varies among fiber types. - Answers true How do cardiac muscles differ from skeletal muscle in excitation-contraction coupling? - Answers Presence of voltage-gated Ca2+ channels in T-tubules. Gap junctions allow direct transmission of electrical signals. Why can smooth muscle contract over a greater length compared to other muscle types? - Answers There are no sarcomeres. Your good friend, Audrey, was just prescribed a new medication by her doctor that blocks the normal binding of Ca2+ to Calmodulin. What side effects would you warn Audrey to be aware of based on the role of Calmodulin in muscle contractions? - Answers Headaches from poor control of the constriction of blood vessels. Digestive issues from the smooth muscles of the digestive tract not contracting rhythmically. What are some properties of positive and negative feedback? - Answers Negative feedback tends to oscillate around a set point. Refer this these figures to answer the following question. Note that i, ii, and iii are flow charts of control systems and iv and v show changes in state variables over time. Which panels correspond to the control of energy balance? - Answers ii, v Based on the above diagram and algorithm, what type of control mechanism is depicted? - Answers Negative feedback.