CH 11 Objectives - Fundamentals OF THE Nervous System AND Nervous Tissue PDF

Preview

Summary

Objectives to prepare for quiz and better understand material...

Description

ANATOMY AND PHYSIOLOGY I CHAPTER OBJECTIVES Chapter 11: Fundamentals of the Nervous System and Nervous Tissue After attending this series of lectures and studying the text and lecture presentations and notes the student should be able to: 1. Describe the functions of the nervous system.   

Gather sensory input Integrate sensory input Cause response or motor output

2. Outline the organization of the nervous system. CNS(brain & spinal cord, integrative control center) and PNS(cranial &spinal nerves, communication lines between CNS and body) PNS Sensory division

Motor division Somatic nervous system

ANS

Sympathetic division

parasympathetic division

3. Describe the functions of the supporting cells of the central nervous system (CNS). Include the functions of astrocytes, microglia, ependymal cells, oligodendrocytes, satellite cells, and Schwann cells. Supporting cells/Neuroglia/Glial cells: “nerve glue” surrounding and wrap neurons Astrocytes- Star shaped, Most abundant, support neurons via anchoring, mop K+ Microglia- transforms into macrophage Ependymal- line central cavities of brain and spinal cord, cilia beat circulating CSF Oligodendrocytes- wrap thicker CNS neurons with cytoplasmic extensions, produce insulating covers-myelin sheaths. Satellite-Surround neuron cell bodies with ganglia, unknown function Schwann- surround and form myelin sheaths around large fibers of PNS, vital for peripheral nerve fiber regeneration 4. Accurately label the lecture diagram of a neuron and describe the functions of the parts.

5. Provide a functional definition of each of the following: dendrite, axon, tract, nerve, ganglia, nuclei, myelin sheath, neurilemma, node of Ranvier, white matter, gray matter. Dendrite- branching receptive/imput, large surface area to synapse with other neurons, convey incoming signals toward cell body Axon- Generates and transmits nerve impulse away from cell body, 1axon/neuron, terminal branches endings =symnaptic butons (release neurotransmitters) Tract-Bundles of Neurons in CNS Nerve-Bundles of Neuron processes in PNS GangliaNucleiMyelin- whitish fatty sheath, covers nerve fibers, protects, electrically insulates, increases speed 150x Nodes of Raniver= gaps between Schwann cells White matter-myleinated fibers Gray Matter-unmyleinated fibers

6. Explain both the structural and functional classification of neurons. STRUCTURAL: Multipolar 

3+ processes 99% neurons

Bipolar   

2 processes (axon & dendrite) Rare Receptors of Retina, Olfactory mucosa

Unipolar 

Single, short process Divides ‘T’ to Proximal & Distal branches

FUNCTIONAL: Direction nerve impulse travels Sensory-afferent

From skin/internal organs  CNS

Motor-efferent  

carry impulse away from CNS  effector organs(muscles/glands) cell bodies in CNS Multipolar

Interneurons-association   

Between motor and sensory Shuttle signals through CNS Often multipolar 99% of neurons

7. Define voltage, current, resistance, and Ohm’s Law. Voltage- potential difference or potential Current—flow of electrical charge from one point to another, flow in body by ions Resistance- hindrance to charge flow, insulators(high resistance), Conductor (low resistance), plasma membrane(resistance)

Ohm’s law= Current(I)= Voltage/Resistance I=V/R 8. Describe and differentiate between the two different types of gated ion channels. Chemically/Ligand gated- open when the appropriate neurotransmitter binds Voltage gated- open and close in response to the changes in the membrane potential. 9. Explain the foundational aspects of neurophysiology, including the following: a.

How the neuron plasma membrane possesses potential energy

b. How the resting membrane potential is maintained c.

How an action potential is generated and propagated

Differences in ionic composition of the intracellular and extracellular fluids and differences in the permeability of the plasma membrane generate the resting membrane potential. Resting membrane potential is measured difference between the charge on the inside and the outside of the membrane. The sodium potassium pumps maintain the concentration gradients resulting in RMP. Action potentials are generated by cells with excitable membranes- neurons and muscle cells. They propagate long distances by action potential.

10. Define and describe the following terms: depolarization, hyperpolarization, local (graded) potential, generator potential, absolute and relative refractory periods. Depolarization- membrane potential moves toward 0(upwards)mV, inside becoming less negative Hyperpolarization-membrane potential increases becoming more negative. Local- small deviation in RMP (graded, ineffective beyond short distance, irreversible, excitatory or inhibitory). Can initiate AP if strong enough. Generator potentialAbsoluteRelative refractory periods- during depolarization of the membrane, nerve cell can’t initiate another action potential

11. Describe the neuronal chemical synapse, including the functions of the following: synaptic vesicle, pre-synaptic neuron, post-synaptic neuron, neurotransmitter receptor, and synaptic cleft. Synaptic vesiclePre-synaptic neuron- houses vesicles filled with neurotransmitters in synaptic knob. Post-synaptic neuron- contains proteins that functions as receptors and ion gates Neurotransmitter- 100+ different chemicals Synaptic cleft12. Explain the basic synaptic integration functions of IPSPs, EPSPs, temporal summation, and spatial summation. IPSP- local hyperpolarization of postsynaptic membrane drives neuron away from AP threshold EPSP- local depolarization of postsynaptic membrane brings neuron closer to AP threshold 13. Describe the process of nerve fiber regeneration. PNS can regenerate if cell body isn’t damaged, some neurilemma remains intact, forms regeneration tube through growing axon reestablishes original connection....