Exam #2: Nerve Flashcards Preview

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Flashcards in Exam #2: Nerve Deck (64):
1

Neuron

Basic structural & functional unit of the nervous system

2

What type of neuron has an angular cell body?

Multipolar

3

What type of neuron has an ovoid cell body?

Bipolar

4

What type of neuron has a spherical cell body?

Pseudo-unipolar

5

Perikaryon

Cell body

6

Multipolar Neuron

- Most common type of neuron in the body
- Euchromatic nucleus (protein synthesis is constant)
- Dark nucleolus
- Nissil bodies

7

Nissil Bodies

Stacks of rER that look like clumps

8

Microtubules

Skeleton of the neuron

9

Neurofilaments

Muscles of the neuron b/c of contractile properties

10

Axon Hillock

- Proximal end of the axon
- Funnel-shaped
- Pale staining b/c lacking rER
- Contains microtubules & microfilaments

11

Lipofuscin

- Old degenerated plasma membrane that cannot be fully degraded by lysosomes & accumulates in the cytoplasm
- Accumulates with age

12

Neuromelanin

Byproduct of DA synthesis (Substantia Nigra)

13

Dendrites

Increase the receptive surface area of the neuron

14

Terminal Bouton

Swollen dilated portions of the axon in with presynaptic terminals

15

Initial Segment

Part of the axon where the nerve terminal is generated

16

Myelin

- Increases conduction velocity
- Insulates axons

17

Does the axon contain rER?

NO!

18

Anterograde Transport

- Flow of substances away from the cell body
- Kinesin micotubule motor protein
- Slow= No ATP
- Fast= ATP

19

What substances are transported via slow anterograde transport?

- Tubulin
- Actin
- Neurofilament proteins

20

Retrograde Transport

- Flow of substances from the axon terminal to the cell body
- Dynein mitrotubule motor protein
- Fast Transport only (ATP)
- Viruses & toxins

21

What substances are transported via fast retorgrade transport?

- sER
- Vesicles
- Mitochondria
- Amino Acids
- Sugars
- Nucleotides
- Ca++

22

Bipolar Neuron

- Associated with the special senses (vision, hearing, balance, smell)
- Dendrite in the periphery
- Axon terminates in brainstem

23

Pseudo-unipolar

- Cell body is located in sensory ganglia
- Axon terminal is in the brainstem
- E.g. Cranial Nerves

24

Afferent

Sensory (toward)

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Efferent

Motor (away)

26

Astrocytes

- Start shaped with astrocytic feet that cover the surface of capillaries
- Form the BBB
- Form scar tissue in response to a lesion
- Monitor ionic & chemical composition of the CSF

27

Microglia

- Phagocytic cells of the nervous system
- Derived from monocytes

28

Astrocytoma

- Most common type of brain tumor
- Arises from astrocytes
- Deforms ventricles

29

Ependymal Cells

Type of neuroglia that lines the ventricles

30

Ependymoma

- Tumor of the 4th ventricle that compresses the surrounding structures
- Rare type of tumor that arises from ependymal cells

31

Unmyelinated axon in the CNS

"naked"

32

Unmyelinated axon in the PNS

Sit in a Schwann cell groove

33

Oligodendrocytes

- Myelinate axons in the CNS
- 3 foot-like processes myeliante 3 axons

34

Schwann Cells

- Myelinate axons in the PNS
- Myelinate 1-to-1

35

Myelin

- Fatty & white b/c of lipid content (Lipoprotein)
- NOT secreted; rather, wraps around the axons

36

Internode

Myelinated portion of an axons

37

Node of Ranvier

Gap between two internodes

38

Clefts of Schmidt-Lanterman

Schwann cell cytoplasm that gets trapped in the concentric layers of the call membrane myelinating the axon

39

Endoneurium

- Connective tissue surrounding individual axons in the PNS
- Contains collagen

40

Perineurium

Connective tissue surrounding a fascile in the PNS

41

Epineurium

- Connective tissue surrounding an entire nerve in the PNS
- Dense irregular collagenous tissue sleeve
- Contains blood & lymphatic vessels

42

Papilledema

Swelling of the optic disc

43

Optic Neuritis

Inflammation of the optic nerve

- Presents with papilledema
- Most common cause is MS

44

Multiple Sclerosis

- Autoantibodies generated against oligodendrocytes
- Triggered by oligodendrogliopathy

45

Nucleus

Collection of nerve cell bodies within the CNS

46

Gray Matter

- Cerebellar Cortex & Cerebral Cortex
- Nuclei deep to Cerebral Cortex
- Nerve cell bodies

47

White Matter

- Myelinated axons
- Tracts
- Nerve cell axons

48

How many pairs of cranial nerves are there?

12

49

How many pairs of spinal nerves are there?

31

50

Voluntary Nervous System

Brain, spinal cord, motor neurons in peripheral nerves

51

Involuntary Nervous System

ANS

52

Sympathetic Nervous System

- Thoracolumbar outflow
- T1-->L2-3

53

Parasympathetic Nervous System

- Craniosacral outflow

54

Axodendritic

- most common type of synapse
- axon terminal & dendrite

55

Axosomatic

Synapse between an axon terminal & membrane of a cell body

56

Axoaxonic

- Least frequent type of synapse
- Synapse between two axon terminals

57

Kiss & Run

Brief attachment & release of only a portion of the contents of a vesicle

58

Collapse

Vesicle attaches & completely empties all of its contents into the synaptic cleft

59

Describe the flow of CSF

1) Choroid Plexus
2) 2x lateral ventricles
3) 3rd Ventricle
4) Cerebral Aqueduct of Sylvius
5) 4th Ventricle
6) Most leaks into the subarachnoid space
7) Remainder goes into the central canal of the spinal cord

60

Arachnoid Granulation

Many arachnoid villi

61

Anterograde Changes in Response to Injury

- Distal segment of axon degenerates
- Elimination of debris by phagocytic cells (Schwann cells & macrophages)
- Schwann cells form tunnels for the axon sprouts to go through

62

Retrograde Changes in Response to Injury

- Swelling of the cell body
- Chromatolysis (Nissil bodies & rER breakdown/ nucleus moves aside)
- Protein synthesis
- Nucleus moves back
- Axon sprouts

63

Fibrous Astrocytes

White Matter

64

Protoplasmic Astrocytes

Gray Matter