Fall2012 Biol 2401 A&P1 The following questions are based on chapters 10, 12, and 14. Total Score 50 1. Label 10 parts of the figure below: 5 2. What are the consequences of severing the vagus/ the X cranial nerve ? 3. A 4 postsynaptic neuron will have an Excitatory Postsynaptic Potential (EPSP) when A) chemically-regulated potassium channels are open and potassium is diffusing out of the cell. B) more calcium ions than usual diffuse into the neuron. C) chemically-regulated sodium channels are open and sodium is diffusing into the cell. D) the neuron is hyperpolarized. E) more potassium ions than usual diffuse out of the neuron. 4. The following are the steps involved in transmission at a cholinergic synapse. 8 1. Chemically-gated sodium channels on the postsynaptic membrane are activated. 2. Calcium ions enter the synaptic terminal. 3. Acetylcholinesterase hydrolyzes acetylcholine. 4. An action potential depolarizes the synaptic terminal at the presynaptic membrane. 5. The synaptic terminal reabsorbs choline. 6. Acetylcholine is released from storage vesicles by exocytosis. 7. Acetylcholine binds to receptors on the postsynaptic membrane. 8. Calcium ions are removed from the cytoplasm of the synaptic terminal. The correct sequence for these events is A) 4, 2, 6, 7, 8, 5, 3, 1. B) 4, 2, 6, 7, 1, 8, 3, 5. C) 2, 4, 6, 7, 1, 8, 3, 5. D) 2, 5, 4, 6, 7, 1, 8, 3. E) 6, 4, 2, 7, 1, 8, 3, 5. 5. The cerebellar hemispheres are separated by a band of cortex called the A) flocculonodular lobe. B) arbor vitae. C) folia. D) vermis. E) pyramid. 6. Hydrocephalus or "water on the brain" may result from A) deficient production of cerebrospinal fluid. B) excessive production of cerebrospinal fluid. C) blockage of circulation of CSF. D) excessive water intake. E) blockage of CSF circulation or excessive CSF production. 7. What contains a spider web-like network of cells and fibers through which cerebrospinal fluid flows? A) subdural space B) dural sinus C) falx cerebri D) subarachnoid space E) pia mater 8. Ependymal cells work to A) surround the capillaries of the choroid plexus. B) secrete CSF into the ventricles. C) remove waste products from CSF. D) adjust the composition of CSF. E) All of the answers are correct. 9. The cardiovascular reflexes are based in the A) cerebrum. B) mesencephalon. C) cerebellum. D) medulla oblongata. E) spinal cord. 10. As you ascend from the medulla oblongata to the cerebrum, the functions of each successive level become A) more complex. B) simpler. C) better understood. D) more crucial to visceral functions. E) critical to reflexes. 11. The sum of the electrical and chemical forces acting on an ion is known as its ________. 12. The ________ principle states that the size and speed of the action potential are independent of the stimulus strength. 13. The tiny gaps between adjacent Schwann cells are called ________. 14. Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated A) spatial summation. B) temporal summation. C) inhibition of the impulse. D) hyperpolarization. E) impulse transmission. 15. Adrenergic synapses release the neurotransmitter A) acetylcholine. B) norepinephrine. C) dopamine. D) serotonin. E) GABA. 16. Ion channels that are always open are called ________ channels. A) active B) gated C) leak D) regulated E) local 17. Communication between axons and muscle fibers occurs at specialized synapses called _____. 18. Extensive damage to oligodendrocytes in the CNS could result in A) loss of the structural framework of the brain. B) a breakdown of the blood-brain barrier. C) inability to produce scar tissue at the site of an injury. D) decreased production of cerebrospinal fluid. E) loss of sensation and motor control. 19. Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because A) oligodendrocytes form a continuous myelin sheath around the axons. B) the endothelium of CNS capillaries forms a blood-brain barrier. C) the neurolemma is impermeable to most molecules. D) ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons. E) astrocytes form a capsule around neurons. 20. Which of the following is not a function of the neuroglia? A) support B) memory C) secretion of cerebrospinal fluid D) maintenance of blood-brain barrier E) phagocytosis 21. Most CNS neurons lack centrioles. This observation explains A) why CNS neurons grow such long axons. B) why CNS neurons cannot divide to regenerate damaged tissue. C) the ability of neurons to generate an action potential. D) the ability of neurons to communicate with each other. E) the ability of neurons to produce a resting potential. 22. A single contraction-relaxation cycle in a muscle fiber produces a ________. 23. In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by A) producing new axons. B) regenerating cell bodies for the neurons. C) forming a cellular cord that directs axonal regrowth. D) clearing away cellular debris. E) producing more satellite cells that fuse to form new axons. 24. Stem cells located between the endomysium and sarcolemma that function in the repair of damaged muscle tissue are called ________. 25. The structural theory that explains how a muscle fiber contracts is called the____________. 26. Which of the following statements is false? A) Cardiac muscle contractions cannot be summated. B) Skeletal muscle contractions may be summated. C) Skeletal muscle stimulation is neural. D) Cardiac muscle stimulation is neural. E) Cardiocytes are interconnected through intercalated discs. 27. Muscles that move the eyeball have A) fast fibers. B) slow fibers. C) intermediate fibers. D) circular fibers. 28. The type of muscle fiber that is most resistant to fatigue is the ________ fiber. A) fast B) slow C) intermediate D) anaerobic E) high-density 29. ) ________ are the most numerous type of neuron in the CNS. A) Sensory neurons B) Motor neurons C) Unipolar neurons D) Bipolar neurons E) Interneurons 30. The function of the astrocytes in the CNS includes which of the following? A) adjusting the composition of the interstitial fluid B) guiding neuron development C) maintaining the blood-brain barrier D) repairing damaged neural tissue E) All of the answers are correct. 31. At the normal resting potential of a typical neuron, its sodium-potassium exchange pump transports A) 1 intracellular sodium ion for 2 extracellular potassium ions. B) 2 intracellular sodium ions for 1 extracellular potassium ion. C) 3 intracellular sodium ions for 1 extracellular potassium ion. D) 3 intracellular sodium ions for 2 extracellular potassium ions. E) 3 extracellular sodium ions for 2 intracellular potassium ions. 33. Rapid impulse conduction from "node" to "node" is called A) spatial propagation. B) saltatory propagation. C) divergent propagation. D) synaptic transmission. E) continuous propagation. 34. Type ________ fibers have the largest diameter axons. A) S B) F C) A D) B E) C 35. The rate of signal propagation along an axon is affected by its_______________ and _______. 36. The following questions are based on the figure below: I) Which area of the graph shows when voltage-gated sodium are open? A) 2 B) 4 C) 1 D) 5 E) 3 II) Which region of the graph shows when passive depolarization is occurring? A) 1 B) 2 C) 3 D) 4 III) Which area of the graph occurs when there is a sudden rush of sodium ions into the neuron? A) 1 B) 2 C) 3 D) 4 IV) Which area of the graph shows repolarization? A) 1 B) 2 C) 3 D) 4 V) Which point of the graph shows hyperpolarization? A) 1 B) 2 C) 3 D) 4 VI) When is the neuron in the refractory period? A) 1 B) 2 C) 3 D) 4