PSA 5 BIOK-103 DR. YOST PDF

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Pre-Session Assignment (PSA) #5

Name ______________________________________________

Complete the vocabulary-matching sections and at least the first three objectives for each chapter. Doing so will prepare you for recitations and for the quizzes. You are highly encouraged to complete the rest of the objectives to keep you on track and so you can ask for clarification during recitation. All answers can be found in the textbook, even if a section has not yet been covered in lecture. Please print, complete, and bring to recitation. Chapter 41 Objectives: Neuronal Signaling __A__ stage in the repolarization time of an action potential when an additional repolarization event is not possible _C___ a branch of an axon _F___ an event that results in the depolarization and formation of an action potential _H___ an event that results in the hyperpolarization of a neuron and the prevention of an action potential _E___ motor neuron __B__ sensory neuron _D___ occurs in unmyelinated axons and is continuous along the length of the axon _G___ support cells of the CNS (not conducting cells) _J___ cell that myelinates neurons in PNS _L___ the neuron leaving a synapse _N___ stage in the repolarization time of an action potential when an additional depolarization event is possible but the threshold level will be higher than during a resting transmembrane potential _i___ combining incoming and outgoing information _k___ cell that myelinates neurons in the CNS _R___ channels that open and close based upon the charge difference across the membrane _O___ movement of an action potential along a myelinated axon where the action potential only occurs at the nodes __Q__ electrical charge difference across a membrane _M___ the neuron leading up to a synapse (the one coming into the synapse) _P___ electrical value at which the voltage-gated sodium channels will be stimulated to open resulting in depolarization

A. Absolute Refractory Period B. Afferent Neuron C. Collateral D. Continuous Conductance E. Efferent Neuron F. Excitatory Post Synaptic Potential G. Glial Cells H. Inhibitory Post Synaptic Potential I. Integration J. Neurolemmocyte K. Oligodendrocyte L. Postsynaptic Neuron M. Presynaptic Neuron N. Relative Refractory Period O. Saltatory Conductance P. Threshold Q. Transmembrane Potential R. Voltage-activated Channels

1. Describe the structure of a typical neuron (multipolar) and give the function of each of its regions/parts (drawing helpful!) The axon is the axon conducting region. The axon terminal is the Secretory region. Dendrites receive stimuli and conduct towards the cell body. Cell body (soma) is the home of the Nucleus, most of cytoplasm and most organelles. The Synapse is the junction between synaptic terminal and effector (neuron, muscle, gland).

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2. Describe the generation of an action potential and draw and label the events that occur during an action potential, compare and contrast the role of sodium and potassium voltage-gated channels in the generation of an axon potential, and explain what happens if either is blocked or stimulated

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The average resting potential is -70 mV. At resting concentration, there are more potassium ions outside the cell and more Sodium on the inside of the cell. The threshold is usually around -55 mV, when this is met, the cell depolarizes. Sodium ions are pumped inside the cell using their designated voltage-gate channels. For every 2 potassium ions in , 3 Sodium ions are also moved out. If one channel is blocked or stimulated, if either of these were blocked, threshold would unable to be met. If a channel was stimulated, the cells would be unable to depolarize again. 3

3. Compare and contrast an absolute refractory period with a relative refractory period After threshold has been met, the cell has a refractory. An absolute refractory period means that the cell cannot meet action potential again to meet threshold. A relative refractory period means may be able to meet threshold again with a stronger stimulus. This is made possible by potassium ion channels. In an absolute refractory period, they are inactive. In a relative refractory period, they are active but “tired”.

4. Describe the processes involved in neural signaling: reception, transmission, integration, and action by effectors

5. Compare and contrast neurons according to their structure [unipolar, bipolar, and multipolar] and their functional roles

6. Name the main types of glial cells and describe the functions of each

7. Explain how the neuron develops and maintains a resting potential (transmembrane potential) and understand what happens if any the parameters (permeability or ion concentration) are changed

8. Compare and contrast three types of ion channels in neuron membranes

9. Describe the involvement of positive and negative feedback in nerve conductance 4

10. Describe the all-or-none response and what determines the intensity of a sensation

11. Compare and contrast continuous and saltatory conduction along axons and describe why action potentials are self propagating

12. Give examples of what might affect the velocity of an action potential

13. Compare and contrast the events that occur at electrical and chemical synapses including disposal of neurotransmitters

14. Compare and contrast inhibitory (IPSP) and excitatory (EPSP) post synaptic potentials as well as integration, temporal and spatial summation of IPSPs and EPSPs. Give specific examples.

15. Describe neural circuits and convergence and divergence of neural circuits

Chapter 42 Objectives: Neural Regulation

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__B__ a centralized control/integration point of the nervous system _E___ crossing over of spinal nerve tracts that occurs in the medulla __G__ nervous tissue that contains only unmyelinated axons, cell bodies, and support cells _A___ responds to changes in the internal environment, controls visceral functions including smooth and heart muscle contraction __D__ when sensory and motor neurons enter and exit on opposite sides of the spinal cord, integration happens in the cord during the crossover to the other side _C___ the brain and spinal cord, located inside a bony enclosure (cranium and vertebrae) _L___ part of CNS located outside of a bony enclosure __F__ a group of nerve cell bodies, in the vertebrate CNS they are located peripherally _J___ when sensory, integration and motor neurons connect on one side of the spinal cord _K___ an axon that has a myelin sheath around it __H__ the convoluted brain tissue of the cerebrum __M__ responds to changes in the external environment, regulates activities under conscious control, coordinates body activities _I___ one half (left or right) of the cerebrum _P___ axons lacking a myelin sheath _Q___ nervous tissue that contains only myelinated axons _N___ furrows (dips between the gyri) that run throughout the cerebrum _O___ a group of nerves carrying similar information such as the olfactory tract or optic tract

A. Autonomic Division of PNS B. Brain C. Central Nervous System (CNS) D. Contralateral E. Decussation F. Ganglion G. Gray Matter H. Gyrus I. Hemisphere J. Ipsilateral K. Myelinated L. Peripheral Nervous System (PNS) M. Somatic Division of PNS N. Sulcus O. Tract P. Unmyelinated Q. White Matter

1. Name the anatomical regions of the adult human brain and describe the functions associated with each (drawing helpful!) The forebrain is responsible for motor and sensory connections. The midbrain is responsible for visual and auditory reflexes. The Pons is responsible for higher reasoning and acts as the bridge of the brain. The medulla regulates life-sustaining functions. The cerebellum is responsible for smooth, coordinated movements.

2. Compare and contrast the general structure of the vertebrate nervous system (CNS and PNS) including all the divisions of the PNS (web helpful!)

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The CNS mostly refers to the brain and the spinal cord. The PNS, however, contains the brain, spinal cord AND all other sensory receptors. These additional parts include sensory and motor neurons. Sensory neurons bring signals into the CNS, and motor neurons carry signals out of the CNS.

3. Describe a simple reflex and the general components of a reflex arc The reflex I have chosen is the withdrawal and cross extensor reflex. First, the nocireceptor picks up on the stimulus. This signal is sent up to the thalamus through afferent neurons. This is then processed and a response signal is sent out via efferent neurons. The body is then able to respond by moving the effected appendage and extending the other.

4. Describe the primary functions of a nervous system

5. Compare and contrast the structure, function and response of nerve nets and bilateral nervous systems in invertebrates including animal examples

6. Describe the withdrawal, muscle spindle reflex, and withdrawal combined with cross extensor reflexes. Also istinguish between an ispsilateral and a contralateral reflexes

7. Recognize that the forebrain, midbrain, hindbrain arose from the neural tube and name the adult brain structures that arose from each

8. Describe the structure and functions of the human cerebrum including the surface anatomy (sulci, gyri, fissure, central sulcus, pre- and postcentral gyrus), the cerebral lobes, and the associated homunculus

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9. Describe the general structure of the spinal cord including the definition of tracts and columns 10. Name and describe the protective barriers of the CNS

11. Define the term drug and where drugs work

12. Define the terms receptor site, receptor affinity, agonist, antagonist, length of effect, ability, effect, and action as they relate drugs

13. Diagram and describe cocaine’s mechanism of action

14. Describe the difference between an intracellular and an extracellular drug

15. Distinguish physical dependence, drug addiction and tolerance

16. Name the major sources of drugs

17. Give examples of drugs obtained from plants and the drug’s function

18. Describe the action of cocaine, strychnine, tetanus, lead, black widow spider venom, curare, and myasthenia gravis 8

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