Nervous Tissue Mediates Perception and Response Flashcards
1
Q
Nervous tissue is characterized by
A
- being excitable
- capable of sending and receiving electrochemical signals that provide the body with information
2
Q
what are 2 main classes of cells make up nervous tissue
A
1 neuron
Two neuroglia
3
Q
neurons
A
- propagate information via electrochemical impulses
- display distinctive morphology
- suited to their role as conducting cells with three parts: cytoplasm, organelles, nucleus
- cateogorized as multipolar neurons have dendrites and a single prominent axon
- biological neurons: single dendrite and axon with cell body
- unipolar neurons: only single process extending out from cell body, which divides into functional dendrite into functional axon
- when neuron is sufficiently stimulated, it generates an action potential that propagates down the axon towards the synapse
- if enough neurotransmitters are released at the synapse to stimulate the next neuron or target (response is generated)
4
Q
Neuroglica
A
- play an essential role in supporting neurons and modulating their information propagation
- simple support role
- word ‘glia’=glue
- recent research is shedding light on more complex role of neuroglia in the function of brain and nervous system
5
Q
Dendrites
A
- branch off cell body and appear as thin extensions
6
Q
myelin
A
- an insulating layer of the long tail axon extends from neuron body
7
Q
synapse
A
- gap between nerve cells
- between a nerve cell and its target (for example, a muscle or gland) across which the impulse is transmitted by chemical compounds known as neurotransmitters
8
Q
astrocyte
A
- named for distinctive star shape, abundant in CNS
- many functions: regulation of ion concentration in intercellular space, uptake/breakdown of some neurotransmitters, formation of blood-brain barrier, membrane that separates circulatory system from brain
- microglia: protects the nervous system against infection but are not nervous tissue because they are related to macrophages
9
Q
Oligodendrocyte cells
A
- produce myelin in CNS (brain and spinal cord)
10
Q
Schwann cell
A
produces myelin in PNS
11
Q
A
