Nervous Tissue Anatomy Flashcards Preview

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Flashcards in Nervous Tissue Anatomy Deck (63):
1

what is the enteric neural system?

innervation of the gut

2

what is the autonomic nervous system?

having to do with the sympathetic and parasympathetic system

3

what is the somatic nervous system?

having to do with the somatic motor neurons

4

what is the soma?

cell body of the neuron

5

what is the telodendria?

branching of the axon with the end-bulb

6

what is an axon collateral?

axon that juts off the major axon

7

what is the axon helliock, initial segment or trigger zone?

area where the first action potential will be generated
-where body of neuron and axon meet

8

what is the graded potential?

areas on the dendrites

9

what is the myelin sheath?

surrounds the axon

10

what do Schwann cells do?

lay down myelin only located in the peripheral nervous system
-one Schwann cell: one node of myelin

11

what do oligodendrocytes do?

lay down myelin in CNS
-can coat many cells

12

what are the nodes of Ranvier

spaces in between Schwann cells where action potentials jump to
-sodium and potassium voltage gated channels are here (not underneath the myelin)

13

what kind of ion channels do nerve cells have?

voltage-gated sodium and potassium channels

14

what is the axolemma?

the plasma membrane of an axon

15

what is the neurolemma?

the plasma membrane of the Schwann cells

16

what are missile substance?

ribosomes within neuron cells

17

do CNS neurons regrow?

no other cells have to take over their function
-don't have centrioles (they don't divide)

18

what is a neuroglial cell?

small, tiny cell, more abundant

19

what are the 4 types of CNS neural cells?

astrocytes
oligodendrocyte
ependymal
microglial

20

what are the 2 types of PNS neural cells?

Schwann cell
satellite cell

21

what are the 3 types of ligands in the body? (substance that binds to a receptor to initiate change)

neurotransmitters
hormones
drugs

22

what kind of ion channels do dendrites have?

ligand (chemically) gated

23

what kind of ion channels do axons have?

voltage gated

24

what is special about neurons?

multitude of neuron transmitters
multitude of ion channels

25

what ion channels are present on the axon?

sodium and potassium exlusively

26

what is the normal picture of neurons

hundreds and thousands of neural cells touching one another

27

what is the main purpose of the dendrite?

increase receptive surface area of the neural cell

28

what does anterograde mean?

moving neurotransmitter from cell body to synaptic end ball
-uses kinesin
-nutrients
-enzymes
-mitochondria

29

which type of protein moves neurotransmitter from synaptic ball to cell body (retrograde)?

dynein
-may send recycled membrane vesicles
-growth factors
-other chemicals
-some diseases

30

alzheimers mechanism

microtubules within neurons get tangles up and stop working

31

what is afferent?

into the CNS (sensory)

32

what is efferent?

away from the CNS (motor)

33

what type of neurons are unipolar?

sensory neurons (most sensory are unipolar)
-cell body is offset from axon

34

what are interneurons?

transfer sensory information to CNS (have short axons)

35

what is important about motor neurons?

cell body is located inside the CNS
usually multipolar

36

where are bipolar neurons?

special senses (retina, olfactory)

37

where in the brain are the Purkinge cells?

cerebellum
largest neuron in the entire CNS

38

where are pyramidal cells found?

frontal lobe of brain in the precentral gyrus

39

corticospinal pathway

from frontal lobe to body

40

nociceptor

pain sensor

41

spinothalamic track

in spinal cord, cross and receives information on the opposite side of brain where injury occurs
-parietal, post sensory cortex

42

what does the astrocyte do?

it is the most abundant of the glial cells
helps the neuron get the nutrients that it needs
-good extracellular environment
-remove waste
-caretaker
-BBB
-fetal development

43

components of BBB

1.tight junctions
2.thick basement membrane in capillaries
3.foot processes of astrocytes sitting on top of the capillaries

44

BBB works against us in which situations?

chemo
antibiotics

45

where do primary brain tumors originate from?

glial cells (neurons can't divide)

46

most common type of brain tumor

astrocytoma

47

what are the two types of astrocytes?

protoplasmic
-present in gray matter
-many short branching processes
fibrous
-present in white matter
-many long unbranched processes

48

what is the pia mater?

inner layer of meninges sitting right on the brain

49

what does a microglia do (spider-like cells)?

phagocytic function (remove cellular debris)
(brain has no lymphatic system other than these cells)

50

what do ependymal cells do?

line the ventricular system of brain and central canal of the spinal cord
-cuboidal/columnar have microvilli, cilia and tight junctions
-produces and maintain the circulation of the CSF

51

what do oligodendrocytes do?

synthesize and maintain the myelin sheath of axons in the CNS

52

what is white matter?

nervous tissue that is myelinated

53

what is gray matter?

nervous tissue that is non-myelinated

54

how does myelin impact speed of conduction?

unmyelinated = slower
myelinated = faster

55

how does size of neural cell impact speed?

wider = faster
thinner = slower

56

ganglion

collection of nerve cell bodies in the PNS

57

what type of cell sits on top of the ganglion?

satellite cells

58

what do satellite cells do?

regulate the exchange of materials between the neurons and the interstital fluid

59

how much myelin do Schwann cells lay down?

specific ratio of axon diameter: myelin diameter

60

how much do axons regrow if peripheral nerve is damaged?

1mm/day

61

how many neurons are killed off when a fetus develops?

50-70% of the original ones

62

where do motor neurons exit SC?

ventral root

63

where do sensory neurons enter SC?

dorsal root

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