Chapter 14- Peripheral Nervous System

Question 1

Peripheral Nervous system made of?

Answer 1

Mixed nerves (contain afferent and efferent axons)- all spinal nerves are mixed nerves
Motor nerves (only efferent axons)
Sensory nerves (only afferent axons)

Question 2

How many pairs of cranial nerves are there?

Answer 2

12

Question 3

Cranial nerves are…

Answer 3

Attached to the brain and pass through the skull foramina; numbered with roman numerals from rostral to caudal; each nerve is either motor, sensory or mixed

Question 4

Identify all 12 cranial nerves from top view of brain

Answer 4

:(

Question 5

CN I: Olfactory

Answer 5

Composed of very short fibers; sensory; doesn’t form tight nerve; bipolar neurons that are olfactory neurons; olfactory bulb is not cranial nerve I it is where olfactory nerve synapses

Question 6

CN II: Optic

Answer 6

Axons of the retina converge to form the optic nerve; passes through the optic foramen into the brain; from eye to chiasma; sensory- vision

Question 7

CN III: oculomotor

Answer 7

Motor- moves the eyeball and eyelid; parasympathetic; activates skeletal muscles that move eyeball

Question 8

Palpebrae=

Answer 8

eyelid

Question 9

CN IV: trochlear

Answer 9

Motor- moves the eyeball; smallest CN; only cn from DORSAL brainstem; innervates the superior oblique muscle and that’s all

Question 10

CN V: trigeminal

Answer 10

MIXED

• Motor: muscles of mastication (chewing only)
• Sensory: All facial sensations

Question 11

CN VI: Abducens

Answer 11

Motor- moves the eyeball

runs along the middle of pons; activates lateral rectus muscles (ABDUCTS the eyeball)

Question 12

CN VII: facial

Answer 12

MIXED

• Motor: Facial expression
• Sensory: taste in anterior 2/3rds of tongue

NOT FOR CHEWING

Question 13

CN VIII: Vestibulocochlear

Answer 13

Sensory- equilibrium and audition

Question 14

CN IX: Glossopharyngeal

Answer 14

MIXED

• Sensory: taste for the posterior 1/3 of the tongue
• Motor: swallowing muscles

Question 15

CN X: Vagus

Answer 15

BIGGEST CN Nerve; only one that goes past the neck (fibers innervate most organs of ventral body cavity); MIXED

• Sensory: visceral sensation and taste from throat region
• Motor: supplies muscles of the pharynx, larynx and soft palate that are involved in swallowing and vocalization

Question 16

Effector tissues of the Vagus Nerve

Answer 16

Lung, heart, spleen, liver, stomach, kidney, small intestine, colon

Question 17

CN XI: Accessory

Answer 17

MOTOR- coordinates head movements

activates sternocleidomastoid and trapezius; through foramen magnum, exit out jugular foramen

Question 18

CN XII: Hypoglossal

Answer 18

Underneath tongue, activates tongue; motor tongue movement

Internal muscles change shape of tongue; external muscles are skeletal muscles

Question 19

Mnemonic

Answer 19

Oh Oh Oh To Touch And Feel Very Good Velvet Ah

Functions: Some Say Marry Money But My Brother Says Big Brains Matter More

Question 20

Is cranial nerve XI attached to the brain?

Answer 20

NO

Question 21

How many pairs of MIXED nerves are attached to the spinal cord?

Answer 21

31

Question 22

How are spinal nerves named?

Answer 22

For their point of issue from the vertebral column

Question 23

of spinal nerves at each segment corresponds to the number of vertebra except

Answer 23

Cervical

Question 24

Below cervical region, all spinal nerves exit ___ their respective vertebra

Answer 24

Below

Question 25

If coming from your limbs it will follow what route?

Answer 25

Ventral Ramus

Question 26

If coming from your back it follows what route?

Answer 26

Dorsal route; sensory must go in dorsal route

Question 27

The _____ of all spinal nerves (except ___) branch and join one another forming an interlacing network of axons

Answer 27

Ventral rami; T2-T12

Question 28

The ventral rami primarily serve...

Answer 28

the limbs

Question 29

Because of the arrangement of the ventral rami, if a single spinal nerve is damaged does it completely paralyze the limb muscle?

Answer 29

NO

Question 30

Back and thorax innervation=

Answer 30

Spinal nerves T2-T12 The dorsal rami supply the back of the trunk in a segmented fashion; The ventral rami of the thorax supplies the remainder of the thorax in a segmented fashion via the intercostal nerves

Question 31

Cervical plexus=

Answer 31

C1-C5 spinal nerves; located deep in the neck under the SCM muscle; phrenic nerve (innervation of the diaphragm)

Question 32

What does spinal cord damage superior to C3 to C5 result in?

Answer 32

respiratory arrest

Question 33

The brachial plexus

Answer 33

Arises from C4-T1; located in neck and axilla region; innervates the shoulders and arms; Ulnar nerve

Question 34

The lumbar plexus

Answer 34

Femoral nerve supplies the anterior thigh; obturator nerve supplies the medial thigh (adductors) Arises from L1-L4; located in psoas major

Question 35

The sacral plexus

Answer 35

Arises from L4-S4 spinal nerves; supplies buttocks, hamstrings, and leg; Sciatic nerve= largest in the body, innervates all of lower limb except anterior and medial thigh

Question 36

Coronial is also known as...

Answer 36

Fibular

Question 37

What are dermatomes?

Answer 37

An area of the skin that provides sensory input to the CNS via one pair of spinal nerves; Clinical relevance? Nerve blocks, localization of injuries