Neuro exam #1 Flashcards
(170 cards)
Excitability
ability to generate an impulse
Conductivity
ability to transmit an impulse within itself
Influence
ability to influence another neuron
Afferent
towards the CNS (ascending)
Efferent
away from the CNS
Interneruron
transmitting from one neuron to another
Oligodendrocytes
make myelin sheath
Astrocytes
accumulate where neurons have been damaged feed blood brain barrier
Ependymal cells
secretion and regulation of CSF
Microglia
remove waste
Nerve regeneration
damaged nerves try to regrow CNS: limited ability PNS: can regenerate
Nerve impulse conduction
travels by the electrical transmission along the axon and the chemical transition between neurons (synapse) until impulse reaches its destination Resting: K high, Na low Depolarization: Na channels open and become high in cell Repolarization: K channels open, slowly enter, K rises and become high in cell again
Action potential
impulse reaches the end of the nerve fiber then transmitted across the junction between nerve cells at the synapse chemical interaction generates another action potential in the next neuron. Repeated until the impulse reaches its destination or end organ
Saltatory conduction
-Nerve conduction of the myelinated cells -action potential jumps from 1 node of Ranvier to the next
Nodes of Ranvier
gaps in myelin sheath
Synapse
Junction where nerve impulse is transmitted from one neuron to another neuron
Synaptic Transmission
presynaptic knob: release impulse synaptic cleft: space between neurons neurontransmitter: chemical involved in impulse from one neuron to another receptor site: next neuron picks up impulse (neurontransmitter: have excitatory or inhibitory effects)
CNS consists of…
brain and spinal cord
PNS….
12 pairs of cranial nerves 31 pairs of spinal nerves
Foramen Magnum
largest hole in the skull. where the spinal cord enters and exits
Meninges
3 protective membranes surround the brain and spinal cord (epidural space: btwn skull and dura) Dura: outer layer. thickest and toughest. (subdural space: below dura. btwn dura and arach) Arachnoid: Middle layer. thinner and more delicate (subarachnoid space: CSF flows here) Pia mater: innermost layer. Mush-like and very vascular.
Falx cerebri
dural fold separates the 2 cerebral hemispheres
Tentoriun cerebelli
-double dura layer folds btwn cerebral hemispheres and cerebellum. -allow for expansion of the one structure w/o altering another.
CSF
clear, colorless, odorless fluid -fills ventricles and subarachnoid space -shock absorber, cushions brain and spinal cord from injury -consists of nutrients (water, protein, O2 , CO2, Na, K, Cl, glucose)- NO RBCs.