1CNS
braina and spinal cord
2PNS
all other parts of the nervous system
3White matter
myelinated axons, supporting cells, neuronal matrix found in the CNS
4Tract
a group of axons running in the CNS (all of which are involved in the same function
5Glia
the matrix in which the axons reside
6Grey matter
neurons and interneurons found in the CNS
7Why does white matter appear white
due to presence of myelin on axons
8Ganglion
a collection of cell bodies found in the PNS
9Nucleus
a collection of cell bodies found in the CNS (all involved in the same function)
10Basal Ganglia
a collection of nuclei in the CNS
11Stereognosis
mental perception of depth or three-dimensionality by the senses, usally in reference to the ability to perceive the form of solid objects by touch
12Types of sensations
touch, temperature, pain, pressure, proprioception, stereognosis
13Rostral
toward the nose (as in the prefontal portion of the frontal lobe)
14Caudal
toward the tail (as in the most inferior aspect of the spinal cord)
15Afferent
inward toward a structure (such as sensory impules traveling towards the CNS)
16Efferent
outward from a structure (such as motor impulses traveling from the CNS)
17Anterograde
substances in the axon traveling from the soma (cell body) to the synapse
18Retrograde
substances in the axon traveling from the synapse to the soma
19Commissure
fibers connecting equivalent structures on the right side of the brain to the left side of the brain
20Ipsilateral
situated or affecting the same side of the body
21Contralateral
situated or affectin the opposite side of the body
22Bilateral
situated or affecting both sided of the body
24Nuroglial cells outnumber nuerons ____ to ____.
10 to 1
25Interneuron
a neuron which transmits impuleses between other neurons, especially as part of a reflex arc
26Axons are fille with _______, lined with a ________ which is thicker than the axon itself
axonoplasm, myelin sheath
27Node of Ranvier
gap between myelin sheaths
28Schwann Cells
myelinated axons in the PNS
29Oligodendrocytes
produce myelin in the CNS
30Schwann Cells
produce myelin in PNS
31Astrocyte
produces the matrix in which the nerve cells reside
32Microglial Cells
phagocytic cell specific to the CNS
33T or F: All nerve cells are myelinated
False: pain cells are ones that would be mostly myelinated while nerve cells that perform peristalsis would be ones that aren’t heavily myelinated
34Electrical Signal
signal propagation WITHIN neuron, branched axon terminus amplifies signal; terminus makes synapses with target cells
35Chemical Signal
propagation BETWEEN cells; neurotransmitters; relay electrical signal via exocytosis and endocytosis; somatic targets - another neuron (dendrites) or muscle cell (NMJ)
36Nerve Signals
changes in the electrical potential across the neuron’s plasma membrane
37An ________ _______ is a regenerating ___________ of membrane potential that propagates along an excitable membrane
action potential; depolarization
38A ________ ____ _________ keeps a neuron relatively negative until an action potential comes along
leaky K+ channel
39Resting neuron electrical level
-90 mv
40Neuron threshold necessary for depolarization
-55 mv
41Overshoot electrical level for an excited neuron
+35 mv
42Depolarization
when the membrane becomes permeable to Na ions INTO the axon
43An action potential is a regenerating ____________ (becoming more positive) of membrane potential that propagates along an excitable membrane
depolarization
44Action potentials actively propagate signal via what channel?
voltage-gated ion channels
45The action potential opens voltag gated _____ channels at the nerve terminal. The increase in ______ triggers the release of ______________ into the synaptic cleft. The _____________ diffuses across the synaptic cleft, binds to the target cell, and triggers an action potential.
Ca+; Ca+; neurotransmitters; neurotransmitter
46Number of NEURONS in the human brain
10-100 Billion
47Number of SYNAPSES in the human brain
10-100 Trillion
48There are 31 pairs of _______ _______ and 12 pairs of _________ ________, both are part of the PNS
spinal nerves; cranial nerves