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Flashcards in Nervous Tissue Deck (52):
1

Functional categories of neurons

Sensory, Interneurons, Motor

2

Prominent organelles in neurons

RER, Golgi body, Euchromatin, large nucleolus, mitochondria, Nissl Bodies

3

Perikaryon

Cell body of a neuron, 5-135 µm

4

Only neurons that are replaced regularly in the body

olfactory neurons

5

Axon cell structure

Can have myelin sheath, no nissl bodies, well-developed SER, microtubules & neurofilaments make up the cytoskeleton

6

Off of what structure does the axon arise from off of the perikaryon?

Axon hillock

7

Anterograde flow

Uses kinesin to transport things from the perikaryon to the axon

8

Slow axonal transport

Moves tubular molecules, actin molecules, proteins (things that form neurofilaments)

9

Fast axon transport

Moves membrane-bound organelles (SER, synaptic vesicles, mitochondria)

10

Fast retrograde transport

Moves endocytosed things to the perikaryon, uses *dynein*

11

Dendritic spines

Where synapses with axonal processes of other neurons are formed

12

Are dendrites myelinated?

dendrites are NOT myelinated

13

Dendrite cell structure

Nissl bodies, tapered, branches profusely, rough surface, no myelin sheaths

14

Types of neurons

Pseudounipolar, Bipolar, multipolar

15

Pseudopolar neurons

Primary sensory neurons, peripheral and central processes
Typically in dorsal root ganglia and cranial nerve ganglia

16

Peripheral processes of pseudounipolar neurons

Reaches into the sensory area and transmits its information

17

Central process of pseudounipolar neurons

Delivers info to the CNS

18

Bipolar neurons

sensory neurons to major sense organs
Have 2 processes: dendrite and axon

19

Multipolar neurons

Most common type of neurons, both motor and interneurons
One axon and many dendrites

20

Golgi type I cells

Long axon multipolar neurons
Large motor neurons in the CNS

21

Golgi type II cells

Short axon multipolar neurons
Smaller interneurons in the CNS

22

What ion creates the negative cell membrane potential?

Na+

23

How do excitatory chemical synapses affect the postsynaptic membrane?

depolarizes the membrane

24

How do inhibitory chemical synapses affect the postsynaptic membrane?

hyperpolarize the membrane

25

Presynaptic knob

Contains synaptic vesicles about 40-60nm in diamete w/ neurotransmitters, has Ca++ channels that initiate the movement of synaptic vesicles to the membrane

26

Synaptic cleft

Space between pre and postsynaptic membrane

27

Postsynaptic membrane

Receptor sites for the neurotransmitters

28

High-affinity reuptake

Extra neurotransmitters are endocytosed back into the presynaptic membrane

29

Degradation of neurotransmitters

Enzymes breakdown neurotransmitters left in the synaptic cleft

30

What treatment involving neurotransmitters has been shown to help with depression?

Inhibition of the enzyme that breaks down norepinephrine/ inhibition of high-affinity reuptake

31

Motor-end plate

Neuromuscular junction that uses acetylcholine

32

Junctional folds

In the sarcolemma of a muscle cells that contain the receptor sites for acetylcholine

33

Curare toxin

Binds to acetylcholine receptor and acts as a muscle relaxant

34

Botulinum toxin

Aka Botox, prevents the release of acetylcholine from synaptic vesicles, relaxes the muscle

35

Myasthenia gravis

Antibodies attack the acetylcholine receptors, weakening the response to stimuli, characterized by extreme muscle weakness

36

What area does the rabies virus affect?

The virus enters the CNS via synaptic terminals, causing serve inflammation, seizures, and death

37

Peripheral Nervous System support cell types

Schwann cells and satellite cells

38

Which cells form the myelin sheaths in the PNS?

Schwann cells

39

How do the action potentials travel in myelin?

Saltatory conduction

40

What is present in high numbers in the nodes of Ranvier that perpetuate the action potential?

Na+ channels

41

How are unmyelinated nerve fibers packed in the PNS?

Multiple nerve fibers surround one Schwann cell

42

Where are satellite cells mainly found?

Ganglia of PNS surrounding individual cells

43

What do satellite cells do for neurons?

Create microenvironments, provide electrical insulation/metabolic exchange necessary for neurons

44

Neuroglia

Forms the intermediate filament cytoskeleton for the cells

45

Astrocytes

Largest neuronal cell (8-10µm), supports the neuron/vascular structures of the CNS, gradual cytoplasm/large nuclei/numerous mitochondria, processes extend between neurons and blood vessels, forms the blood-brain barrier

46

Types of astrocytes

Protoplasmic and Fibrous

47

Protoplasmic astrocytes

Found in grey matter, have perivascular feet along blood capillaries

48

Fibrous astrocytes

Have more prominent cytoskeletons, are primarily found in white matter

49

Astrocytomas

Tumors from astrocytes, 20% of all brain tumors, 80% of tumors that originate in the brain

50

Glial Scar

Formed by astrocytes after brain tissue damage has been done

51

Oliodendrocysts

The most common neuroglia (6-8µm), Small nuclei/abundant SER/prominent Golgi, form myelin sheaths in the CNS

52

Multiple Sclerosis

Damage to CNS myelin sheaths via the immune system