Histology - ANS and PNS

Question 1

Answer 1

Question 2

What parts of the neuron receive the excitatory and inhibitory signals?

Answer 2

Soma and dendrites

Question 3

If cell body receives enough excitatory signals, it will approach threshold.

True/False

Answer 3

True

Question 4

Where on a neuron are the highest density of Na+ channels?

Answer 4

Nodes of ranvier

Question 5

What is the ion channel profile like at the axon hillock?

Answer 5

Transitioning from ligand gated / GPCR to voltage gated Na+ and K+

Question 6

In […] syndrome, anitbodies against schwann cells are produced which causes the schwann cells to be opsonized by the host’s own immune system and the result is unmyelinated neurons.

Answer 6

Guillain-Barré syndrome

Question 7

Answer 7

Question 8

What are nissl bodies?

Answer 8

Rough endoplasmic reticulum with a rosette of ribosomes

Question 9

Answer 9

Question 10

Answer 10

Question 11

When referring to a multipolar, unipolar, or bipolar neuron, what is the “polar” portion?

Answer 11

The number of sensory poles

Question 12

Answer 12

Question 13

What is the difference between a schwann cell and an oligodendrocyte?

Answer 13

Schwann cells myelinate only 1 portion of 1 axon in PNS

Oligodendrocytes can myelinate multiple portions of the same axon or multiple portions of different axons in CNS

Question 14

[…] myelinate axons in PNS

Answer 14

Schwann cells

Question 15

[…] myelinate cells in CNS

Answer 15

Oligodendrocytes

Question 16

Answer 16

Question 17

Describe the process of myelin sheath forming in the PNS.

Answer 17

The schwann cells wraps itself around the axon multiple times folding its cytoplasm over itself for many turns

Question 18

Answer 18

Question 19

Answer 19

Question 20

Answer 20

Question 21

What is this structure and how do you know?

Answer 21

Dorsal root ganglia –> indicated by central nucleus that has an “owl’s eye” appearance

Question 22

Answer 22

Question 23

The myelinated axons are located in the […] matter

Answer 23

White

Question 24

The cell bodies and dendrites are located in the […] matter

Answer 24

Grey

Question 25

The [...] carries efferent signals away from the spinal cord

Answer 25

Ventral nerve

Question 26

The [...] is the site in the spinal cord where efferent signals are generated.

Answer 26

Ventral horn

Question 27

The [...] carries signals from the body to the spinal cord.

Answer 27

Dorsal nerve

Question 28

Sensory signals from the body terminate at the [...] in the spinal cord

Answer 28

Dorsal horn

Question 29

Where are the alpha motor neurons of the spinal cord located? What is unique about these neurons?

Answer 29

Ventral horn They are the largest cells in the CNS

Question 30

Answer 30

Question 31

Are unmyelinated cells truly unmyelinated?

Answer 31

No - they are loosely myelinated. They possess a single concentric layer of myelin around the axon.

Question 32

* Unmyelinated cells are also called [...] * They transmit [...] signals * Their conduction speed is [...] * Their diameter is [...]

Answer 32

* C-fibers * Pain * Slow * Small

Question 33

Neurons with their cell bodies in the brain that are part of the corticospinal tract have their synapse in the [...] of the spinal cord.

Answer 33

Ventral horn

Question 34

What is the structure that is boxed? What are they?

Answer 34

Schmidt - Lanternman Incisures These arise from a build up of cytoplasm when the schwann cell is wrapping itself around the axon

Question 35

What is the boxed structure and what does it contain?

Answer 35

Question 36

Can you tell the difference between sympathetic and parasympathetic nerves on a histology slide?

Answer 36

No

Question 37

In the sympathetic nervous system, the preganglionic nerves originate in the [...] and they are [...] in length. They synapse on postganglionic nerves that are located [...] the spine and are [...] in length.

Answer 37

* Thoracic and lumbar division of the spinal cord * Short * Near * Long

Question 38

In the parasympathetic nervous system, the preganglionic nerves originate in the [...] and they are [...] in length. They synapse on postganglionic nerves that are located [...] and are [...] in length.

Answer 38

* Brain (they are cranial nerves) and sacral spinal nerves * Long * near the tissues they innervate * Short

Question 39

What are the vertebral column levels that correspond to sympathetic preganglionic nerves?

Answer 39

T1 - L2

Question 40

What are the parasympathetic cranial nerves?

Answer 40

3, 7, 9, 10

Question 41

What regions of the sacral spine contain parasympathetic preganglionic nervs?

Answer 41

S2 - S4

Question 42

What is the general role of the sympathetic NS?

Answer 42

Fight or flight

Question 43

What is the general role of the parasympathetic NS?

Answer 43

Rest and digest

Question 44

All [...] nerves are myelinated. All [...] nerves are unmyelinated.

Answer 44

Preganglionic Postganglionic

Question 45

What are chromaffin cells?

Answer 45

Cells that are located in the adrenal medulla that produce epinephrine and norepinephrine and release them into the blood vessels

Question 46

Answer 46

Question 47

Answer 47

Question 48

Answer 48

Question 49

Label these structures.

Answer 49

Green = epineurium Blue = perineurium

Question 50

Answer 50

Blue = perineurium Green = epineurium