Lecture 7 - neuroanatomy intro Flashcards
Exam 2
Differentiate between classifications of neurons based on myelination
A - myelinated (motor functions)
B - lightly myelinated (slower, pressure, cold)
C - no myelination
Motor neurons are type ___ neurons
A
How are A-type neurons subdivided?
Size: alpha > beta > gamma > delta
Cell body
Soma (nucleus)
Dendrites
- receiving ends; project from soma
- can be excitatory or inhibitory
Dendrites are not _____
myelinated
Differentiate between EPSP and IPSP
ESPS - excitatory post-synaptic potential; more positive than average Vrm (-20mV) → depolarization
IPSP - inhibitory post-synaptic potential; more negative than average Vrm (-70mV) → hyperpolarization
**If cell Vrm is -60mV
Neurons can have _______ connections with their neighbors
10,000+ (especially decision makers) → takes a lot of info and decides if to act with AP
______ is the sending end of the neuron; send AP quickly (usually myelinated)
Axon
The end of the axon is the ______ and releases _______
presynaptic terminal; neurotransmitters
______ is the beginning part of the axon that is connected to the soma
Axon hillock
Inputs coming from the nervous system that tend to suppress activity in the neuron occur at the ______
Axon hillock - brakes for the nervous system
The neurotransmitter that typically acts at the axon hillock is _____
GABA
GABA receptors on the axon hillock increase ________ permeability
chloride
The more chloride permeability, the more _____ of cell
inhibition
_______ is GABA receptor agonist
Alcohol - the body doesn’t produce much of its own GABA with chronic alcohol use → seizures and overactivity in CNS
Natural inhibition of HR is mediated by ______, while natural inhibition of the nervous system is mediated by _____
mACh receptors linked to K+ channels
GABA at the axon hillock
Why are there no excitatory connections at the axon hillock?
it would bypass the rest of the neuron (dendrites and soma) - cell would no longer be the decision maker for all the connections from the rest of the nervous system
Glial cells are much more _______ than neurons
proliferative
A brain tumor is probably a ______ tumor instead of a neuron tumor
glial
The smallest of the glial cells are the ______
microglia
What are the 3 types of macroglia?
Astrocytes, Ependymal cells, Schwann cells/Oligodendrocytes
_______ are a big part of the BBB. How?
Astrocytes - wrap themselves around capillaries
The walls of astrocytes don’t directly constitute the BBB
The BBB is found inside the capillaries of endothelial cells (tight junctions)
Astrocytes are named because they look like a _____
star - appendages connect to the outside of the endothelial cells