Lecture 1 Intro to NS

Question 1

The spinal nerve splits into what?

Answer 1

Rami

1. Posterior Ramus
2. Anterior Ramus

Question 2

Which Ramus is smaller?

Answer 2

• The posterior (dorsal) ramus

Reason: the posterior ramus only supplies the deep muscles of the back and the skin on top

Question 3

Which Ramus is larger?

Answer 3

• The anterior (ventral) ramus

Reason: because it has more axons and supplies and receives information from the entire body

Question 4

A collection of cell bodies in the PNS

Answer 4

Ganglia

Question 5

Where do we find the majority of our cell bodies?

Answer 5

Grey matter

Note: you also have some in the PNS (called dorsal root ganglion)

Question 6

Organization of the spinal cord roots

Answer 6

rootlets converge –> dorsal root and ventral root converge –>spinal nerve (exit spinal column)–> split tinto dorsal and ventral ramus

Question 7

what kind of information does the dorsal root carry?

Answer 7

only sensory information

Question 8

what kind of information does the ventral root carry?

Answer 8

only motor information

Question 9

The roots carry only sensory or motor…

Answer 9

Always one or other, not both
Dorsal - sensory
Ventral - motor

Important!!!

Question 10

Where does the dorsal root ganglion reside?

Answer 10

on the dorsal root

Question 11

where are your sensory neuron cell bodies located? and what kind of neurons are they?

Answer 11

dorsal root ganglion

unipolar neurons (1 process off the cell body that splits)

Question 12

which NS is the dorsal root ganglion associated with?

Answer 12

The somatic nervous system

Important!!

Question 13

What carries both sensory and motor information?

Answer 13

Spinal nerve
Dorsal and ventral rami

Question 14

Rami are essentially…

Answer 14

nerves

Question 15

What converges to form spinal nerve?

Answer 15

dorsal and ventral roots

Question 16

where do we exit the spinal cord?

Answer 16

the spinal nerve and it travels to the periphery

Question 17

What are the 3 layers of the meninges?

Answer 17

1. Dura mater
2. Arachnoid mater
3. Pia mater

Question 18

Pia mater

Answer 18

• deepest layer
• sits on surface of spinal cord

Question 19

Arachnoid mater

Answer 19

• middle layer

Question 20

What sits below the arachnoid mater and contains CSF?

Answer 20

Subarachnoid space

Question 21

Toughest and most superficial layer of meninges that surrounds spinal cord and protects it?

Answer 21

Dura mater

Question 22

What is in the extradural space? and what is its purpose?

Answer 22

blood vessels and fat
- insulates/ protects spinal cord in vertebral canal

Question 23

How many spinal nerves do we have? Breakdown

Answer 23

31

8 Cervical (in neck) -
but only have 7 cervical vertebrae
12 Thoracic
5 lumbar
5 sacral
1 coccygeal

Question 24

all the cervical spinal nerves exit above or below there same named bone?

Answer 24

above
EX: C4 exits above bone C4
so it exits between C3 and C4

Question 25

Where does C8 exit?

Answer 25

**between bone C7 and T1**

Question 26

Where do the majority of spinal nerves exit above or below there same named bone?

Answer 26

**below** EX: T5 exits below T5 so it exits between T5 and T6 bone

Question 27

Where does L1 exit?

Answer 27

below L1 so between bone L1 and L2

Question 28

Function of Nervous system?

Answer 28

- Receive sensory input from body > send to CNS to interpret and integrate it > send out a motor response

Question 29

Voluntary output refers to

Answer 29

Skeletal muscles and our **Somatic NS**

Question 30

Involuntary output refers to

Answer 30

smooth muscles and glands **Autonomic NS**

Question 31

What does the Peripheral NS consist of?

Answer 31

1. Cranial Nerves 2. Spinal Nerves

Question 32

afferent means

Answer 32

going toward the CNS - Think arriving

Question 33

efferent means

Answer 33

going away from the CNS - Think exiting

Question 34

How do we divide the PNS?

Answer 34

Somatic (voluntary) Autonomic (involuntary)

Question 35

how many neurons is the somatic motor pathway associated with?

Answer 35

a **single motor neuron** located in the **ventral** horn a single long axon

Question 36

how many neurons is the visceral motor pathway associated with?

Answer 36

**2** neuron chain from the **lateral horn** has a pre and post ganglionic axon

Question 37

Preganglionic neurons of the autonomic NS originate from the

Answer 37

CNS and travel to a ganglion

Question 38

Postganglionic neurons of the autonomic NS originate from the

Answer 38

PNS and travel away from ganglion

Question 39

Sympathetic preganglionic fibers are ------ and postganglionic are -------

Answer 39

pre - short post - long

Question 40

parasympathetic preganglionic fibers are ------ and postganglionic are -----

Answer 40

pre- long post - short

Question 41

Sympathic originate

Answer 41

between T1 and L2 called the racholumbar

Question 42

Parasympathetic originate

Answer 42

from the cranial nerves and sacral region "craniosacral"

Question 43

The nerves coming from the sacral region called the pelvic splanchnic nerves are associated with

Answer 43

parasympathetic

Question 44

Major contribution of the PNS innervation to visceral organs comes from

Answer 44

vagus nerve (cranial nerve 10)

Question 45

what does the Vagus nerve do?

Answer 45

slow down heart rate and slow down breathing

Question 46

Major contribution of the PNS innervation pelvic organs is from the

Answer 46

pelvic splanchnics

Question 47

we enter the sympathetic trunk via the ..... and exit via the ......

Answer 47

Enter via the white ramus communicans exit via the grey ramus communicans

Question 48

Innervation of the gut and ** sympathetic NS** you think of the

Answer 48

Splanchnics

Question 49

What are the three thoracic Splanchnics?

Answer 49

1. Greater 2. Lesser 3. Least

Question 50

Where does the **greater** splanchnic originate and what does it supply?

Answer 50

around T5-T9/T10 supplies upper digestive tract

Question 51

Where does the **lesser** splanchnic originate and what does it supply?

Answer 51

around T9-T11 supplies the middle digestive tract

Question 52

Where does the **least** splanchnic originate and what does it supply?

Answer 52

around T12 supplies the lower digestive tract