lecture 7 Flashcards
1
Q
neurons
A
- excitable cells
- carry electrical signals (fire action potentials or release neurotransmitters)
- several types
~ classified based on structure/function
2
Q
glial cells (neuroglia)
A
- non-excitable cells
- provide physical and biochemical support for neurons (act as a supporting cell)
- several types
~ classified based on location/function
3
Q
Glial cells (in CNS)
A
- ependymal cells (create barrier between carpartments)
- astrocytes (sweep up)
- microglia cells (act as immune cells)
- oligodendrocytes (form myelin)
4
Q
Glial cells (in PNS)
A
- satellite cells (provide physical support)
- schwann cells (form myelin)
5
Q
dendrites
A
receives incoming signals
6
Q
cell body (soma)
A
integrates information
7
Q
axon
A
carry outgoing information to the axon terminal
information is passed to the next (post synaptic) neuron or other target cell (e.g. muscle, gland)
8
Q
Neuron =
A
1cell
9
Q
Nerve=
A
a bundle of axons from multiple neurons
10
Q
Node of Ranvier
A
region of unmyelinated axon membrane between two schwann cells
—> action potentials are generated here
11
Q
diseases of demyelination include
A
- multiple sclerosis: autoimmune degeneration of myelin in CNS; progressive
- guillain-barré syndrome: autoimmune degeneration of myelin in PNS; sudden onset and usually temporary
demyelination causes impaired conduction of electrical signals along the axon
12
Q
graded potential
A
- depolarization or hyperpolarization
(excitatory (EPSP) vs inhibitory (IPSP) post-synaptic potential) - amplitude of response depends on strength of stimulus and density of receptor channels
- electrical signal travel in form of ionic charge (+ or -) diffuse through the cell
- response diminishes with distance
13
Q
action potential
A
- depolarization only
- all-or-none response depends on the membrane reaching threshold potential
- needs high density voltage gated Na+ channels for this type of signal
14
Q
explain how electrical signals are produced in neurons
A
- Signal input in dendrites
- change in ion permeability
- generation of graded potential - Graded potential spreads through soma and reaches axon hillock where there is a high density of voltage gated Na+ channels
—> if threshold is reached, initiates action potential - action potential is propagated along axon
- at axon terminal, action potential triggers neurotransmitter release
- Neurotransmitter binds to receptors on postsynaptic dendrites/membrane
15
Q
Ohms law equation
A
V=IR
