Nervous Tissue Histology Flashcards Preview

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Flashcards in Nervous Tissue Histology Deck (42):
1

what are the 3 functions of the nervous system

1 - sensory input
2 - motor output
3 - processing and integration

2

what is a collection of axons called in the nervous system

nerve

3

what are the 2 basic types of cells found in nervous tissue

-neurons/nerve cells
-glia/neuroglia/supporting cells

4

which basic cells of the nervous system are the excitable cells

neurons

5

which are more abundant in the nervous system, neurons or glia cells

glia cells (can divide/multiply)

6

what are the 3 special characteritics of neurons

longevity
amitotic
high metabolic rate

7

clumps of rough ER and ribosomes found in the cell body

Nissl bodies

8

what is a perikaryon and what is its main function

neuron cell body, its the biosynthetic control center of nuueron

9

in a neuron, what parts of the basic structure is/are myelinated

axon =myelin
dentrite and cell body = unmyelinated

10

what is a axon terminal

storage area of nerve transmitters, its the secretory portion of the cell that can then signal the next neuron

11

where is the AP generated in a neuron

axon hillock

12

difference b/w anterograde and retrograde movement in a neuron

anterograde - AP goes from cell body to axon terminal
retrograde - AP goes form axon terminal to cell body

13

what are the 3 types of neurons based upon structure

Multipolar(most) , bipolar (rare) , unipolar

14

what are the 3 types of neurons based on function

afferent (sensory), efferent (motor), interneurons

15

multipolar neurons carry out what neuron function

motor(efferent) or internuerons

16

bipolar neurons carry out what function

special sensory neurons

17

unipolar neurons carry out what function

general sensory neurons

18

what are the 2 most common types of synapses

axodentritic (axon terminal and dendrite)
axosomatic (axon terminal and cell body)

19

what is the difference b/w presynaptic and postsynaptic neurons

pre is signal carrier before synapse
post is carrying signal after synapse

20

what is the difference b/w electrical and chemical synapses

electrical - neurons can touch and exchange AP via gap junctions, rapid communication
chemical - slower cuz must transfer AP to a chemical signal to diffuse across synaptic cleft, then back to electrical AP

21

explain the process of transferring information across a chemical synapse

1- impulse arrives at synaptic cleft
2- depolarization opens voltage gated Ca channels
3 - Ca signals release of neurotransmitter
4- neurotransmitter diffuses across synaptic cleft
5-neurotransmitter binds and opens ligand gate channel
6 - ions flow across postsynaptic membrane = AP

22

what are the 3 ways a neurotransmitter can be removed from a postsynaptic receptor in a chemical synapse

1 - enzymatic degradation
2 - recycled by presynaptic terminal for later use
3 - diffusion out

23

what are the 4 neuroglia cells found in the CNS

astrocyte, microglial, ependymal, oligodendrocyte

24

what are the 2 neuroglia cells found in the PNS

schwann cells, satellite cells

25

what neuroglia cells in the CNS are predominant in the white matter

oligodendrocytes

26

what neuroglial cell in CNS is predominant in the gray matter ?

astrocytes (largest of all glial cells)

27

what is the difference b/w oligodendrocytes and schwann cells

oligodendrocytes - in CNS, wrap many axons
schwann cells - in PNS, wrap 1 axon

28

what neuroglia cells would be found lining ventricular spaces of the brain, and what are their function

ependymal cells - regulate blood-CSF barrier of choroid plexus

29

which glial cell can be recognized by its elongated nucleus, what is the cells role ?

microgli cells - immune defense for CNS (originate from monocytes)

30

what makes the white matter in the CNS white ?

myelin sheath made form oligodendrocytes

31

what makes the gray matter in the CNS actually gray

lack of myelin and numerous Nissl bodies

32

what is a cluster of nerve cell bodies in the CNS called

nucleus

33

what is a cluster of nerve cell bodies found in the PNS called

ganglion

34

what is a bundle of neuronal axons in the CNS called

tract

35

what is a bundle of neuronal cell bodies found in the PNS called

nerve

36

what are the 3 connective tissue coverings around nerve from largest to smallest

epineurium, perineurium, endoneurium

37

how many pairs of cranial nerves are there and where do the originate from

12 pairs at the brain

38

how many pairs of spinal nerves are there and where do they originate from

31 and originate at the spinal cord

39

what is the function of a myelin sheath

protect and insulate axons from others
increase speed (more myelin=faster impulse conduction)

40

what is the neurilemma in PNS

area outside of myelin sheath in a nerve fibers that contains the organellses and nucleus of schwann cells

41

the rate of impulse propagation down an axon depends on what two things

axon diameter, presence of myelin

42

what is the difference b/w continuous vs. salutatory conduction

continuous is for unmyelinated axons
salutatory is for myelinated axons and regenerates AP at every node of ranvier