Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
What makes myelin in the CNS? |
Ogliodendrocytes |
|
|
What makes myelin in PNS |
Schwann Cells |
|
|
What components make up a synapse? |
nerve terminal, synaptic cleft, and postsynaptic membrane |
|
|
Nerve |
multiple neurons bundled together in the PNS |
|
|
3 types of PNS nerves? |
sensory, motor, mixed |
|
|
What is a ganglia |
Found in the PNS. They are the cell bodies of neurons of the same type clustered together |
|
|
tracts |
In the CNS axons are bundled into tracts. Unlike nerves they only carry one type of info. |
|
|
nuclei |
The cell bodies of the neurons in the same tract are grouped in nuclei |
|
|
gllial cells, or neuroglia cells |
structural and supportive role |
|
|
astrocytes |
nourish neurons and form the blood brain barrier which controls the transmission of solutes from the bloodstream to the nervous tissue |
|
|
ependymal cells |
line the ventricles of the brain and produce cerebrospinal fluid, which physically supports the brain and serves as a shock absorber |
|
|
microglia |
phagocytic cells that ingest and break down waste products and pathogens in the CNS |
|
|
action potential |
all or nothing signals in a neuron |
|
|
resting membrane potential |
-70 mV on the inside of the neuron, maintained by the sodium/potassium pump |
|
|
Na/K pump |
pumps three sodium ions out of the cell for every two K ions pumped in |
|
|
temporal summation |
refers to the addition of multiple signals near each other in space |
|
|
spatial summation |
refers to the addition of multiple signals near each other in space |
|
|
what is the threshold voltage? |
-50 Mv |
|
|
What happens to sodium? |
Sodium flows into the cell when it becomes depolarized, raising the the action potential at +35 the na channels inactivate |
|
|
What happens to K |
Potassium channels open when the action potential reach +35 mV, and K flows out of the cell -- and repolarizes it |
|
|
absolute refractory period |
cell cannot fire another action potential |
|
|
relative refractory period |
cell can fire, but it needs a stronger than normal signal to cause it . |
|
|
3 ways that neurotransmitters are removed from the synapse? |
1. broken down 2. taken back up 3. diffuse out |
|
|
White matter |
myelinated axons in the brain white matter is deeper than gray this is reversed in the spinal cord |
|
|
gray matter |
unmyelinated axons |
|
|
Two divisions of the PNS |
1. somatic 2. autonomic
|
|
|
reflex arcs |
use the ability of interneurons in the spinal cord to relay information to the source of the stimuli while also routing it to the brain |
|
|
monosynaptic reflex arc |
the sensory neurons fires directly on the motor neuron |
|
|
polysynaptic reflex arc |
the sensory neuron may fire onto a motor neuron as well as interneurons that fire onto other motor neurons. Ex. withdrawal reflex |
