Lecture 7 part one (SECOND MIDTERM)

Question 1

In an adult, one mesentery “goes away.” Which one is it?

Answer 1

Ventral mesentery

Question 2

How many collections of axons?

Answer 2

2, and they go out into the peripheral nervous system

Question 3

What is the “hole” inside of your spinal cord?

Answer 3

the central canal

Question 4

Gray matter:

White matter:

Answer 4

Gray matter: gray because it contains bundles of cell bodies (nuclei) and they aren’t wrapped in myelin!
White matter: the area with bundles of axons (tracts)

Question 5

Remember…
Bundles of cell bodies in the CNS:
Bundles of axons in the CNS:

Answer 5

cell bodies: nuclei

axons: tracts

Question 6

Bundles of axons in the PNS:

Answer 6

nerves

Question 7

When does it become a “nerve?”

Answer 7

When the dorsal portion and the ventral portion come together into a single bundle

Question 8

What is the portion called that isn’t yet a nerve?

Answer 8

a root
(dorsal root and ventral root)

Question 9

Sensory information is brought into the spinal cord via what?

Answer 9

Dorsal roots

Question 10

What contains the axons of motor neurons that extend into the periphery to control somatic and visceral effectors?

Answer 10

Ventral roots

Question 11

Both of the sensory nuclei are inside of what?

Answer 11

both somatic and visceral are in the dorsal (posterior) gray horn

Question 12

Where are the motor nuclei located?

Answer 12

in their OWN horns!

visceral: lateral gray horn
somatic: ventral (anterior) gray horn

Question 13

What do the motor and sensory nuclei have in common?

Answer 13

The somatic nuclei are the most superficial compared to the motor nuclei

Question 14

The only cells that are going to contribute to the ventral root are the ones that are in the ______________.

Answer 14

motor nuclei

*so you will only have motor or efferent axons in the ventral root!

Question 15

The only ones communicating with the sensory nuclei are the axons traveling in the _____________.

Answer 15

dorsal root

*that means the dorsal root is only carrying sensory information by afferent axons!

Question 16

What is a ganglion? Where?

Answer 16

collection/bundle of cell bodies in the PNS

Question 17

What do the dorsal root ganglia contain?

Answer 17

cell bodies of sensory neurons

Question 18

Dorsal root ganglion is a result of having what kind of neuron morphology?

Answer 18

(pseudo)unipolar neurons

Question 19

A “mixed” spinal nerve is what?

Answer 19

They are spinal nerves that contain both afferent (sensory) and efferent (motor) fibers

Question 20

The roots come together and form a ________, which then splits into a ____________ and a __________.

Answer 20

trunk

dorsal ramus and ventral ramus

Question 21

In the adult cross-section, there is no longer a __________!!

Answer 21

Notochord (intervertebral discs)

Question 22

What does the coelom separate?

Answer 22

visceral serosa from parietal serosa

Question 23

Dorsal ramus division:

Ventral ramus division:

Answer 23

Dorsal: epaxial
Ventral: hypaxial

Question 24

What root is associated with sensory and where are the cell bodies?

Answer 24

• Dorsal root

- Cell bodies are inside the dorsal root ganglia

Question 25

What did Noriega say “fiber type” means?

Answer 25

Somatic afferent
Visceral afferent
Somatic efferent
Visceral efferent

Question 26

Inside of the dorsal root, different ______ can be carried.

Answer 26

fibers

Question 27

Autonomic nervous system is only to be considered…

Answer 27

motor

Question 28

From the ventral ramus, what kind of information is going to be returned?

Answer 28

visceral sensory information; vessels and other unconscious structures of hypaxial region

Question 29

From the dorsal ramus, what kind of information is going to be returned?

Answer 29

somatic sensory information; vessels, glands of epaxial region

Question 30

Upper motor neurons are referring to:

Answer 30

CNS neurons; coming down from brain, running through spinal tracts, going into motor nuclei, synapse onto lower motor neurons

Question 31

Lower motor neurons are referring to:

Answer 31

cell bodies in the CNS with axons that extend into PNS

Question 32

For somatic efferent…

Answer 32

Upper motor neuron comes down into somatic efferent nucleus > synapse onto cell body > somatic efferent sends single out through ventral root (somatic efferent fiber) > into mixed spinal nerve > has access to epaxial or hypaxial regions

Question 33

For visceral efferent…

Answer 33

AUTONOMIC NERVOUS SYSTEM!

-basically forget about upper motor neurons and refers to ANS as a 2 motor neuron system

Question 34

The visceral efferent goes where?

Answer 34

Goes through the ventral root but goes DOWN through the “white communicating ramus” that communicated with an autonomic ganglion.

Question 35

The autonomic ganglia are located…

Answer 35

near your vertebral bodies (actually form a pair of structures that go up and down your vertebral column) and its only for the SYMPATHETIC NERVOUS SYSTEM

Question 36

What do we call the autonomic ganglia?

Answer 36

Sympathetic ganglia

Question 37

Preganglionic:
Postganglionic:

Answer 37

Pre: white ramus
Post: gray ramus

Question 38

The signal that goes to the sympathetic ganglia via the white ramus goes back to the mixed nerve via what?

Answer 38

the gray ramus

Question 39

Where does the grey ramus go?

Answer 39

If it goes..
dorsal ramus: epaxial (unconscious)
ventral ramus: hypaxial (unconscious)

Question 40

What happens if you send a signal to the sympathetic ganglion and it does NOT go to the hypaxial or epaxial regions?

Answer 40

The postganglionic neuron can go deeper inside the body and provide visceral efferent innervation to your thoracic organs (lungs, heart)

Question 41

What happens if a preganglionic neuron travels through the ventral root, mixed spinal nerve, down the white communicating ramus and does NOT synapse inside of the sympathetic ganglion?

Answer 41

It will completely pass it and go all the way to a completely different sympathetic ganglion located inside of your abdominal cavity