Nervous System Flashcards
return to resting potential
repolarization
membrane potential inside the cell increases (becomes more ++++)
depolarization
resting potential for neurons
-70mV (“polarized”)
Lack of pore between capillary cells in the brain, instead joined by tight joint junctions (and other channels/proteins, etc)
Blood-brain barrier
Major excitatory neurotransmitter, released from CNS axon terminals
glutamate
major inhibitory NT, made from glutamate
GABA
most abundant glial cell
influence interactions between neurons + between neurons and blood
astrocytes
form myelin sheaths around peripheral axons in the PNS
Schwann cells
support cell bodies within the ganglia of the PNS
Satellite cells
form myelin sheaths in the CNS
oligodendrocytes
migrate around CNS tissue + phagocytize foreign/degenerated material
microglia
line the ventricle’s central canal of spinal cord + secrete cerebrospinal fluid
Ependymal cells
single short process, branches like a T to form 2 longer processes
ie. sensory neurons
pseudounipolar neurons
2 processes, one on either end
ie retina of the eye
bipolar neurons
several dendrites and one axon
ie motor neurons
multipolar neurons
shuttle for second messengers, made of 3 subunits
G-proteins
second messenger to activate cell change, made from ATP
cAMP
cyclic adenosine monophosphate
cell signaling that involves glands secreting hormones into bloodstream
endocrine
cell signaling that involves neurons secreting neurotransmitters across a synapse
synaptic
cell signaling where cells within an organ secrete molecules to diffuse extracellularly to nearby target cells
paracrine
cell signaling where regulatory molecules act on the same cell that released the molecule
autocrine
resting potential of most cells is between:
-65mV — -85mV
Ek for K+
-90mV
Ek for Na+
+66mV
membrane potential inside the cell decreases (becomes more negative)
hyperpolarization
threshold voltage for Na+ channels
-55mV
Na+ channels deactivate at: (voltage)
+ 30mV
stronger stimuli activate more neurons
recruitment
after an action potential has been reached, neurons cannot become excited again
refractory period
during the action potential, Na+ channels are inactive (not just closed)
absolute refractory period
K+ channels are still open, but only a VERY strong stimulus can overcome and cause another action potential
relative refractory period
in myelinated neurons, action potentials “leap” from node to node
Saltatory conduction
functional connection between a neuron and the cell it is signaling
synapse
enclose neurotransmitters in the axon terminus before signaling
synaptic vesicles
Ca+ sensor in neuron
synaptotagmin
anchors synaptic vesicles to plasma mebrane
SNARE complex proteins
ACh receptor, ligand-gated for 2 ACh, creates an EPSP
nicotinic receptors
