Anatomy and Physiology Final Review

carries both sensory and motor neurons

What does it mean for a nerve to be mixed?

Dorsal rami and ventral rami

For spinal nerves, which parts are mixed?

mixed

Almost all peripheral nerves are ___; carry both sensory and motor nerve fibers

very short

sensory nerves are

spinal nerves and rami

are mixed; only spinal roots are unmixed

I

olfactory

II

optic

III

oculomotor

IV

Trochlear

V

Trigeminal

VI

Abducens

VII

Facial

VIII

Vestibulocochlear

IX

Glossopharyngeal

X

Vagus

XI

Accessory

XII

Hypoglossal

triceps brachii and posterior extensor

The radial nerve innervates ___ and ___ muscles of the forearm and hand

wrist drop

- Damage to the radial nerve (e.g. due to improper use of crutches or cut or stab wound) result in
- unable to extend hand at the wrist

radial nerve

Based on its location in the axilla (armpit), which nerve is most likely to be compressed by improper use of crutches or falling asleep in the bathtub with one arm hanging over the side of the tub?

endoneurium

loose areolar CT; encloses axons and their myelin sheaths

perineurium

coarse CT, bundles the nerve fibers into fascicles

epineurium

though fibrous CT that surrounds entire nerve

1st order neurons

- unipolar sensory neurons attached to sensory receptors in the periphery

dorsal

1st order neurons enter the spinal cord via the ___ roots

white, medulla

- 1st order neurons ascend in the dorsal ____ matter (dorsal columns) to the ____
- synapse with 2nd order neurons

decussate

2nd order neurons ____ (cross over to opposite side) and ascend

thalamus

2nd order interneurons ascend to the ____ and synapse with 3rd order neurons

primary somatosensory cortex

3rd order interneurons project from the thalamus to the ____ _____ _____ in the postcentral gyrus for conscious touch and proprioception

ventral roots

motor neurons exit the spinal cord via

somatic motor neurons

travel to skeletal muscles for voluntary movement

autonomic motor neurons

innervate smooth muscle, cardiac muscle, and glands

descend

motor tracts ____ to carry motor output from the primary motor cortex

ascend

sensory tracts ___ to carry sensory input to the primary somatosensory cortex

cerebral cortex - gray matter

thin outer region on the surface; appears gray

cerebral white matter

deeper part of the hemispheres; appears white

unmyelinated

gray matter (cerebral cortex) appears gray because it consists of ____ parts of multipolar neurons

myelinated

white matter appears white because it consists mostly of ___ (and some unmyelinated) axons

axon

only the ___ of a neuron is myelinated. Myelin appears white, but the rest of the neuron is not myelinated

dendrites, cell bodies, and axon terminals

in the cerebral cortex thin outer layer of gray matter consist of

carpal tunnel, pincer grip

- The median nerve passes anteriorly down arm and forearm
- Passes through ___ ____
- Innervates flexor muscles in forearm, palm and fingers 1-3, and part of 4
- Is compressed in __*_ __*__
- Damage causes loss of " ____ ____"
Damage to the median nerve is common in wrist-slashing

flexor retinaculum

-may need to be cut to relieve nerve compression for carpal tunnel syndrome
- repetitive overuse of flexors causes inflammation of the sheaths that enclose each tendon; they swell, press on median nerve; cause pain, numbness

dorsal rami, posterior

(the smaller branches of the spinal nerves) innervate the _____ trunk
- Sensory neurons come from skin and proprioceptors
- Motor neurons course to skeletal muscles along the back

ventral rami, lateral and anterior, entire

- ___ ____ innervate the ____ and ____ neck and trunk
- innervate the ____ upper and lower limbs

plexuses

all ventral rami (except T2 - T12) form ____ (networks of nerves)

intercoastal nerves

In thoracic region ventral rami form the ____ _____ instead of forming a plexus

C1 - C4

cervical plexus formed by ventral rami of

C5 - C8 and T1

brachial plexus formed by ventral rami of ___ - ____and ___

L1 - L4

lumbar plexus formed by ventral rami of

L4 - S4

sacral plexus formed by ventral rami of

post central

The primary somatosensory cortex is located in the ___ ___ gyrus

conscious touch

The primary somatosensory cortex receives sensory information from the skin for ____ (includes pain, itch, vibration, pressure, temp.)

proprioception

The primary somatosensory cortex receives sensory information from the skeletal muscles and joints for ___ (awareness of limb position, joint movement, muscle stretch)

spatial discrimination

The primary somatosensory cortex is capable of ___ ___ - localizes the body region being stimulated

left, right, greatest

- the primary somatosensory cortex (postcentral gyrus) of the __ hemisphere receives sensory input from the __ side of the body
- enlarged areas of the postcentral gyrus receive the ____ amount of input for conscious touch and proprioception and are the most sensitive body areas
- Note: the postcentral gyrus does not receive input for vision, hearing, smell, or taste

sensory tracts

ascend to the primary somatosensory cortex for conscious touch and proprioception

excitable

motor neurons become more ___; spontaneously fire APs that set off muscle contractions

Excitation-contraction coupling

the sequence of events by which an AP (an electrical event) in the sarcolemma of the muscle cell initiates the sliding of the myofilaments, resulting in contraction (a mechanical event).

5

the brachial plexus form __ major nerves that innervate the upper limb

median nerve, ulnar nerve, and radial nerve

brachial plexus nerves of clinical significance

ulnar

- the ___ nerve passes anteriorly along the arm and parallel to ulna
- superficially exposed as it passes over the distal end of the humerous

flexors, 4-5

the ulnar nerve innervates the forearm ___ and fingers __ - ___

claw hand

damage to the ulnar nerve causes "___ ____" (fingers 4-5 become flexed at distal interphalangeal joints, but hyperextended at the knuckle joints)

radial, posterior

the ___ nerve descends ____ to humerus; then anterior then __*__ and parallel to radius

optic nerves (CN II)

what nerve signals partially cross over (decussate) at the optic chiasma and continue to the thalamus

nasal mucosa

olfactory nerves sensory receptors are located in the ___ ___ (olfactory nerves CN I)

bipolar sensory neurons

form olfactory nerves that pass through olfactory foramina of the cribriform plate of the ethmoid bone (an inside cranial bone) (olfactory nerves CN I)

ethmoid

cribriform plate of the ___ bone (olfactory nerves CN I)

olfactory bulbs

fibers synapse with neurons in the ____ (olfactory nerves CN I)

primary olfactory cortex

olfactory signals are carried to the ____ (olfactory nerves CN I)

forebrain

olfactory nerves enter the ___ (frontal lobes of the cerebral hemispheres) (olfactory nerves CN I)

olfaction

Olfactory nerves is purely sensory for sense of ______(smell) (olfactory nerves CN I)

anterior two-thirds of the tounge

sensory function (taste) from the _____ __-__ ___ ___ ____(facial nerves CN VII)

skeletal

somatic motor neurons to _____ muscles of facial expression (facial nerves CN VII)

lacrimal glands, salivary glands

parasympathetic motor neurons to
1.) ____ ____ for tear production
2.) ____ ____ (sublingual and submandibular glands) for salivation (facial nerves CN VII)

bell's palsy

inflammation of the facial nerves may result in ____ ___ - paralysis of facial muscles and partial loss of taste sensation (facial nerves CN VII)

medulla, pharynx

fibers emerge from ____ and leave skull via jugular foramen towards the _____(glossopharyngeal nerves CN IX)

facial nerves (CN VII)

functions overlap somewhat with ____ _____(glossopharyngeal nerves CN IX)

posterior one-third of the tongue

sensory fibers from the ___ ___ ___ ___ ___ and pharynx for taste, touch and pressure (glossopharyngeal nerves CN IX)

tongue and pharynx

somatic motor neurons to some muscles in ___ and ____ for swallowing (glossopharyngeal nerves CN IX)

salivary glands

parasympathetic motor neurons to ____ ___ (parotid glands) for salivation (glossopharyngeal nerves CN IX)

face and teeth

sensory fibers innervate ___ and ___ for touch, pain and temperature (trigeminal nerves CN V)

chewing

Somatic motor fibers innervate ____ muscles (temporalis masseter muscles) (trigeminal nerves CN V)

sensory

functions are general ____ for all 3 divisions (trigeminal nerves CN V)

mandibular

the _____ division also carries somatic motor neurons to skeletal muscles (trigeminal nerves CN V)

largest

the trigeminal nerves is the _____ of the cranial nerves (trigeminal nerves CN V)

medulla oblongata, thorax and abdomen

fibers emerge from ___ ___ and leave skull via jugular foramen and descend towards ___ and ___ (vagus nerves CN X)

heart, lungs, digestive, taste buds

sensory fibers come from ____, ____, ____ organs (stretch receptors, chemoreceptors) and ____ ___ on the epiglottis (extralingual) (vagus nerves CN X)

swallowing

somatic motor neurons project to pharyngeal constrictor muscles for ____ (vagus nerves CN X)

muscles for swallowing

superior pharyngeal constrictor, middle pharyngeal constrictor, and interior pharyngeal constrictor (vagus nerves CN X)

heart, lungs, abdominal

most fibers in vagus are parasympathetic motor neurons to
1.) ___ (slows the _*__)
2.) ____ (constricts smooth muscle in bronchioles
3.) ___ organs to promote digestion
(vagus nerves CN X)

90

___% of all parasympathetic fibers are carried in the vagus nerves (CN X) (vagus nerves CN X)

rest and digest

the vagus nerve is involved in " ____ and ____" functions (vagus nerves CN X)

only

vagus nerve is the ____ pair of cranial nerves that extends beyond the head and neck region (vagus nerves CN X)

thoracic and abdominal

the vagus nerve innervate organs in ____ and ____ cavities (vagus nerves CN X)

buttock

the sacral plexus serves the ___, lower limb

sciatic nerve

nerve of clinical significance in sacral plexus

longest and thickest

the sciatic nerve is the ____ and thickest nerve of the body

extension and leg flexion

the sciatic nerve innervates the hamstring muscles in posterior thigh for thigh ___ and leg ____

muscles

the sciatic nerve innervates most ___ in the leg and foot