Download Central and Peripheral Nervous Systems: Neurons, Neuroglia, and Electrical Activity and more Quizzes Physiology in PDF only on Docsity!
Central Nervous system
-Brain +spinal cord (control + integration) TERM 2
peripheral nervous system
DEFINITION 2 -cranial nervers and spinal nerves )communication: connects CNS to sensory receptors, muscles, and glands) -note the white cns vs the purple pns TERM 3
Cell types : neurons
DEFINITION 3 conduct electrical signals (action potential) TERM 4
neuroglia:
DEFINITION 4 majority of all nerve tissue cells, support neurons "glia cells" TERM 5
cell body:
DEFINITION 5 nucleus and typical organelles
dendrites
recieve stimulation TERM 7
axon
DEFINITION 7 conduct electrical signals ( action potentials) -often associated with a myelin sheath TERM 8
axon hillock
DEFINITION 8 site where AP's originate TERM 9
Axon terminals
DEFINITION 9 where chemical signals are released pink cells discussed later, but areas that are between the pink cells where axon is exposed is called the node of ranvier TERM 10
Sensory (afferent) neurons
DEFINITION 10 -part of the PNS -transmit electrical signals from tissues to CNS -detect changes in environment and relay info to controller
Types of neuroglia:perphial nervous system
(supporting cells) aka glia cells TERM 17
schwann
DEFINITION 17 wraps around axon -surronds all PNS axons -forms neurilemma -guide regeneration of damaged axons -form myelin sheaths around many axons TERM 18
Types of neuroglia: central nervous system.
1.oligodendroctyes
DEFINITION 18 form myelin sheath around axons TERM 19
2.astrocytes
DEFINITION 19 control permeability of capillaries in CNS (blood brain barrier) and Support neuronal activity TERM 20
3.microglia
DEFINITION 20 engulf foreign/ degenrated material
4. ependymal
cells:
form epithelial linging of brain and spinal cord cavities TERM 22
Myelination
DEFINITION 22 myelin sheath formed by wrapping plasma membrane of certain nueroglia repeatedly around axon insulates axon with multiple lipid bilayers ***accelerates electrical signal transmission TERM 23
schwann cells
DEFINITION 23 single flat cells wrapped repeatedly around axon segment - gaps b/t are nodes of radvier -in pns TERM 24
oligodendrocytes
DEFINITION 24 form myelin sheath by wrapping processes around multiple individual axons -in cns TERM 25
electrical activity of neurons: resting
membrane potential
DEFINITION 25 due to differences in permeability of membrane to charges particles -completly impermeable to A- - relatively permeable to K+ - relatively impermeable to Na+ inside of cell negative relative to the outside - -70 mV for many neurons At resting membrane potential, neither K+ or Na+ are at equilibrium
action potentials
"allornone"response
-axon hillock must be depolarized to the threshold potential for voltage- gated channels to open -if depolarized to (or beyond) treshold, voltage-gated channels will open and action potential (AP)will depolarize as much as possible -if threshold no0t reached, volatage- gated channels do not open and no AP will occur TERM 32
Depolarization
DEFINITION 32 -triggering event causes membrane to depolarize -relatively slow increase until treshold potential is reached -both volatge- gated Na+ channels (quickly) and K+ channels(slowly) begin to open As voltage- gated Na+ channels open, Na+ enters cells
