Nervous System Flashcards
2 Major Regulatory Systems Of The Body
Nervous & Endocrine Systems
Both Specialized To Make The Proper Responses To Stimuli
2 Important Properties Of Neurons
Excitability: Ability To Respond To A Stimulus
Conductivity: Ability To Transmit A Signal
Neuroglia
Specialized Cells That Support Neurons
Ex. Phagocytize Foreign Substances, Produce Cerebrospinal Fluid, Form Myelin Sheaths Around Axons
CNS
Brain & Spinal Cord
PNS
All Nervous Tissue Outside CNS
Delivers Sensory Info To CNS & Carries Motor Commands To Peripheral Tissues & Systems
Divisions Of PNS
Somatic Nervous System (SNS)
Automatic (Autonomic) Nervous System (ANS)
Divisions Of SNS
Somatic Afferent (Sensory) Division Somatic Efferent (Motor) Division
Somatic Afferent Division
Receives Sensory Info & Conveys It To CNS Via Nerves
Somatic Efferent Division
Regulates Contraction Of Skeletal Muscles Via Neuronal Pathways From CNS To Lower Motor Neurons
ANS
Consists Of Sensory & Motor Neurons That Conduct Impulses To Smooth & Cardiac Muscles & Glands
(Involuntary)
Motor Portion Of ANS
Sympathetic Division
Parasympathetic Division
3 Parts Of Neurons
Cell Body
Dendrites
Axon
Neurotubles
Function in the intracellular transport of proteins and other substances, in both directions between the cell body and the other ends of the processes
Neurofilaments
Provide a skeletal framework for the axon
Dendrites
Thread-like projections which are actually extensions of the cell body
Conduct nerve impulses towards the cell body
Axons
Neuron Generally Has Just One Which Extends From Cell Body
Carries nerve impulses away from cell body to next neuron, muscle cell, or gland
Originates From Axon Hillock
Initial Segment
Site Where Action Potential Is Initiated
Lies Immediately After Axon Hillock
Collateral Branches
Side Processes That Axons May Possess
Telodendria
Spray Of Small Axon Branches Which End In Tiny Swellings Called “End Bulbs”
The Synapse
Junction Between End Bulb Of One Axon & Another Neuron, Muscle, Or Gland
Site Where Info. Is Transferred
Neurolemmocyte
(Schwann Cells)
Form myelin sheaths around axons in the PNS
Oligodendrocyte
Form myelin sheaths in the CNS
Myelin
Layers Of A Lipid Sheath Covering Axons
Segmented
Neurilemma Sheath
Outer Layer Of Myelin
Nodes Of Ranvier
Gaps Between Myelin Sheaths
Internode
Distance Between A Node Of Ranvier & The Next Node
Multipolar Neurons
Many Dendrites & Single Axon
Bipolar Neurons
Single Dendrite & Axon
Conducts Action Potentials To CNS
Unipolar Neurons
Only Have One Axon
Peripheral Ends Have Dendrite-like Processes
