Nervous Tissue

Question 1

Functional categories of neurons

Answer 1

Sensory, Interneurons, Motor

Question 2

Prominent organelles in neurons

Answer 2

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

Question 3

Perikaryon

Answer 3

Cell body of a neuron, 5-135 µm

Question 4

Only neurons that are replaced regularly in the body

Answer 4

olfactory neurons

Question 5

Axon cell structure

Answer 5

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

Question 6

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

Answer 6

Axon hillock

Question 7

Anterograde flow

Answer 7

Uses kinesin to transport things from the perikaryon to the axon

Question 8

Slow axonal transport

Answer 8

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

Question 9

Fast axon transport

Answer 9

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

Question 10

Fast retrograde transport

Answer 10

Moves endocytosed things to the perikaryon, uses dynein

Question 11

Dendritic spines

Answer 11

Where synapses with axonal processes of other neurons are formed

Question 12

Are dendrites myelinated?

Answer 12

dendrites are NOT myelinated

Question 13

Dendrite cell structure

Answer 13

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

Question 14

Types of neurons

Answer 14

Pseudounipolar, Bipolar, multipolar

Question 15

Pseudopolar neurons

Answer 15

Primary sensory neurons, peripheral and central processes

Typically in dorsal root ganglia and cranial nerve ganglia

Question 16

Peripheral processes of pseudounipolar neurons

Answer 16

Reaches into the sensory area and transmits its information

Question 17

Central process of pseudounipolar neurons

Answer 17

Delivers info to the CNS

Question 18

Bipolar neurons

Answer 18

sensory neurons to major sense organs

Have 2 processes: dendrite and axon

Question 19

Multipolar neurons

Answer 19

Most common type of neurons, both motor and interneurons

One axon and many dendrites

Question 20

Golgi type I cells

Answer 20

Long axon multipolar neurons

Large motor neurons in the CNS

Question 21

Golgi type II cells

Answer 21

Short axon multipolar neurons

Smaller interneurons in the CNS

Question 22

What ion creates the negative cell membrane potential?

Answer 22

Na+

Question 23

How do excitatory chemical synapses affect the postsynaptic membrane?

Answer 23

depolarizes the membrane

Question 24

How do inhibitory chemical synapses affect the postsynaptic membrane?

Answer 24

hyperpolarize the membrane

Question 25

Presynaptic knob

Answer 25

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

Question 26

Synaptic cleft

Answer 26

Space between pre and postsynaptic membrane

Question 27

Postsynaptic membrane

Answer 27

Receptor sites for the neurotransmitters

Question 28

High-affinity reuptake

Answer 28

Extra neurotransmitters are endocytosed back into the presynaptic membrane

Question 29

Degradation of neurotransmitters

Answer 29

Enzymes breakdown neurotransmitters left in the synaptic cleft

Question 30

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

Answer 30

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

Question 31

Motor-end plate

Answer 31

Neuromuscular junction that uses acetylcholine

Question 32

Junctional folds

Answer 32

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

Question 33

Curare toxin

Answer 33

Binds to acetylcholine receptor and acts as a muscle relaxant

Question 34

Botulinum toxin

Answer 34

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

Question 35

Myasthenia gravis

Answer 35

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

Question 36

What area does the rabies virus affect?

Answer 36

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

Question 37

Peripheral Nervous System support cell types

Answer 37

Schwann cells and satellite cells

Question 38

Which cells form the myelin sheaths in the PNS?

Answer 38

Schwann cells

Question 39

How do the action potentials travel in myelin?

Answer 39

Saltatory conduction

Question 40

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

Answer 40

Na+ channels

Question 41

How are unmyelinated nerve fibers packed in the PNS?

Answer 41

Multiple nerve fibers surround one Schwann cell

Question 42

Where are satellite cells mainly found?

Answer 42

Ganglia of PNS surrounding individual cells

Question 43

What do satellite cells do for neurons?

Answer 43

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

Question 44

Neuroglia

Answer 44

Forms the intermediate filament cytoskeleton for the cells

Question 45

Astrocytes

Answer 45

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

Question 46

Types of astrocytes

Answer 46

Protoplasmic and Fibrous

Question 47

Protoplasmic astrocytes

Answer 47

Found in grey matter, have perivascular feet along blood capillaries

Question 48

Fibrous astrocytes

Answer 48

Have more prominent cytoskeletons, are primarily found in white matter

Question 49

Astrocytomas

Answer 49

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

Question 50

Glial Scar

Answer 50

Formed by astrocytes after brain tissue damage has been done

Question 51

Oliodendrocysts

Answer 51

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

Question 52

Multiple Sclerosis

Answer 52

Damage to CNS myelin sheaths via the immune system