cranial and spinal nerves lab

How many pairs of cranial nerves are there?

12 pairs

Cranial nerves arise from where?

The brain

Spinal nerves arise from where?

The spinal cord

What body region do cranial nerves primarily serve?

The head and neck

Which cranial nerve extends into the thorax and abdomen?

Vagus nerve (CN X)

Which two cranial nerves arise from the forebrain instead of the brainstem?

Olfactory (CN I) and Optic (CN II)

What does sensory (afferent) mean?

Body to brain

What does motor (efferent) mean?

Brain to body

Which cranial nerve is CN I?

Olfactory nerve

Function of the olfactory nerve (CN I)?

Smell

CN I is sensory, motor, or both?

Sensory

Damage to CN I causes what?

Loss of smell (anosmia)

Which cranial nerve is CN II?

Optic nerve

Function of the optic nerve (CN II)?

Vision

CN II is sensory, motor, or both?

Sensory

Damage to CN II causes what?

Blindness or vision loss

Which cranial nerve is CN III?

Oculomotor nerve

CN III is sensory, motor, or both?

Motor

Function of CN III?

Most eye movements and pupil constriction

Which cranial nerve is CN IV?

Trochlear nerve

CN IV is sensory, motor, or both?

Motor

Function of CN IV?

Moves the superior oblique muscle of the eye

Which cranial nerve is CN V?

Trigeminal nerve

CN V is sensory, motor, or both?

Both

Main sensory function of CN V?

Sensation of the face

Main motor function of CN V?

Chewing (mastication)

Three branches of the trigeminal nerve?

Ophthalmic, Maxillary, Mandibular

Which branch of CN V supplies the forehead and eye?

Ophthalmic (V1)

Which branch of CN V supplies the cheek?

Maxillary (V2)

Which branch of CN V supplies the jaw and chewing muscles?

Mandibular (V3)

Which cranial nerve is CN VI?

Abducens nerve

CN VI is sensory, motor, or both?

Motor

Function of CN VI?

Moves the eye laterally

Which cranial nerve is CN VII?

Facial nerve

CN VII is sensory, motor, or both?

Both

Functions of CN VII?

Facial expression, taste (anterior 2/3 of tongue), salivary and lacrimal glands

Which cranial nerve is CN VIII?

Vestibulocochlear nerve

CN VIII is sensory, motor, or both?

Sensory

Function of CN VIII?

Hearing and balance

Which cranial nerve is CN IX?

Glossopharyngeal nerve

CN IX is sensory, motor, or both?

Both

Functions of CN IX?

Taste (posterior 1/3 of tongue), swallowing, salivary gland

Which cranial nerve is CN X?

Vagus nerve

CN X is sensory, motor, or both?

Both

Functions of CN X?

Controls pharynx, larynx, and thoracic/abdominal organs

Which cranial nerve is CN XI?

Accessory nerve

CN XI is sensory, motor, or both?

Motor

Function of CN XI?

Controls sternocleidomastoid and trapezius muscles

Which cranial nerve is CN XII?

Hypoglossal nerve

CN XII is sensory, motor, or both?

Motor

Function of CN XII?

Tongue movement

What is a peripheral nerve?

A bundle of myelinated and unmyelinated axons surrounded by connective tissue

What connective tissue surrounds the entire peripheral nerve?

Epineurium

What connective tissue surrounds fascicles?

Perineurium

What connective tissue surrounds each axon?

Endoneurium

Cranial nerves arise from what?

Brain

Spinal nerves arise from what?

Spinal cord

Functional classification of peripheral nerves?

Mixed nerves (contain sensory and motor fibers)

What is a ganglion?

A cluster of neuron cell bodies in the PNS

What is the dorsal root ganglion?

Cluster of sensory neuron cell bodies

What is an autonomic ganglion?

Cluster of motor neuron cell bodies of the autonomic nervous system

How many pairs of spinal nerves are there?

31 pairs

Spinal nerves supply what?

Body except the head

How many cervical spinal nerves?

8 (C1-C8)

How many thoracic spinal nerves?

12 (T1-T12)

How many lumbar spinal nerves?

5 (L1-L5)

How many sacral spinal nerves?

5 (S1-S5)

How many coccygeal spinal nerves?

1 (Co1)

Which spinal root contains motor fibers?

Ventral root

Which spinal root contains sensory fibers?

Dorsal root

Where are sensory neuron cell bodies located?

Dorsal root ganglion

What is formed when dorsal and ventral roots join?

A mixed spinal nerve

What are the two branches of a spinal nerve?

Dorsal ramus and ventral ramus

What does the dorsal ramus supply?

Posterior body trunk

What does the ventral ramus supply?

Anterior/lateral trunk and limbs

What is a dermatome?

Area of skin supplied by one spinal nerve

Shingles commonly follows what pattern?

A dermatome

Thoracic ventral rami form what?

Intercostal nerves

Which ventral rami form plexuses?

All except T2-T12

Name the four nerve plexuses.

Cervical, Brachial, Lumbar, Sacral

Cervical plexus spinal levels?

C1-C4

Important nerve of the cervical plexus?

Phrenic nerve

What does the phrenic nerve innervate?

Diaphragm

Brachial plexus spinal levels?

C5-T1

Major nerves from the brachial plexus?

Axillary, Musculocutaneous, Median, Ulnar, Radial

What does the brachial plexus supply?

Upper limb

Lumbar plexus spinal levels?

L1-L4

Major nerves from the lumbar plexus?

Femoral and Obturator nerves

What does the lumbar plexus supply?

Anterior thigh, abdominal wall, psoas

Sacral plexus spinal levels?

L4-S4

Major nerve from the sacral plexus?

Sciatic nerve

What does the sacral plexus supply?

Buttock, lower limb, pelvis, and perineum