Nervous System Flashcards
1
Q
Neurons
A
Specialized cells that transmit electrical signals and transduce them into chemicla signasl.
2
Q
Soma
A
- Cell body
- Location of ER and nucleus
3
Q
Dendrites
A
Receive incoming signals from other cells
4
Q
Axon hillock
A
Integrates incoming signals. If signal is excitatory enough, it will initiate an action potential.
5
Q
Myelin
A
- Insulation that covers the axon to prevent signal loss or crossing of signals between adjacent neurons.
- Schawnn Cells: PNS
- Oligodendrocytes: CNS
- Spaces in myelin sheath are called nodes of Ranvier
6
Q
Axon terminal
A
- Increased surface area to maximize neurotransmission.
7
Q
Synapse
A
- nerve terminal, synaptic cleft, and postsynaptic membrane
8
Q
Astrocytes
A
- nourish neurons and form blood-brain barrier, which controls the transmission of solutes from the bloodstream into nervous tissue
9
Q
Ependymal cells
A
- Line ventricles of brain and produces csf
10
Q
Microglia
A
- phagocytic cels that ingest and break down waste and pathogens in CNS
11
Q
Oligodendrocytes and schwann cells
A
- Produce myelin around axons
- Oligodendrocytes: myelinate many neurons
- Schwann cells: myelinate one cell
12
Q
Action potential
A
13
Q
Absolute refractory
A
- Cell is repolarizing
- VG Na+ channels have not reset
- No AP can be generated
14
Q
Relative refractory
A
- VG Na+ Channels have reset
- AP can be generated but stimulus must be stronger because membrane is hyperpolarized
15
Q
Neurotransmitter release
A
- AP causes influx of Ca2+
- Ca2+ surrounds NTv, which allows the binding to the terminal membrane
- NT release via exocytosis
17
Q
Spinal Cord
A
18
Q
A
- somatic motor neurons synapse directly upon effects.
- Para and Symp NS neurons synapse upon other neurons with ganglia
- Ganglia: collection of cell bodies in PNS
