02 NPTE Neuromuscular and Nervous Systems Review

Central Nervous System

Brain, Brainstem, Spinal Cord

Brain Divisions

Forebrain (prosencephalon)

Midbrain (mesencephalon)

Hindbrain (Rhombencephalon)

Brainstem Sections

Midbrain

Pons

Medulla Oblongata

Forebrain (Prosencephalon)

Contains:

Telencephalon

-Cerebrum

-Hippocampus

-Basal Ganglia

-Amygdala

Diencephalon:

-Thalamus

-Hypothalamus

-Subthalamus

-Epithalamus

Midbrain (Mesencephalon)

Tectum:

-Superior and inferior Colliculi

Tegmentum:

-Cerebral Aquedut

-Periaqueductal Gray

-Reticular Formation

-Substantia Nigra

-Red Nucleus

Hindbrain (Rhombencephalon)

Metencephalon

-Cerebellum, Pons

Myelencephalon

-Medulla Oblongata

Gray Matter

Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.

White matter

Myelinated axons, nerve fibers without dendrites

Lobes of the brain

Frontal, Parietal, Occipital, Temporal

Peripheral Nervous System

the sensory and motor neurons that connect the central nervous system to the rest of the body.

Made up of Autonomic Nervous System and the Somatic Nervous System

-12 Cranial Nerves and Ganglia

-31 pairs of spinal nerves exit vertebral column through intervertebral foramina:

8 Cervical

12 Thoracic

5 lumbar

5 Sacral

1 Coccygeal

Efferent Fibers

Carry motor signals from CNS to effectors

Afferent Fibers

Carry sensory signals from receptors to CNS

Ganglia

clusters of cell bodies in the PNS. They give rise to peripheral and central nerve fibers.

Autonomic Nervous System

Division of PNS that controls glands and muscles of internal organs. Largely automatic responses that don't reach consciousness and emphasize homeostasis and stress response. Contains two divisions:

Sympathetic: Emergency response, Norepinephrine transmission, stimulating response. "Fight or flight"

Parasympathetic: Conserving/restoring energy, ACh transmittion, inhibitory response. "Feed and breed"

Somatic Nervous System

Division of PNS that controls muscles.

Voluntary movements, ability to touch, smell, see, taste, and hear.

Limbic System

A doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; involved in control/expression of moddoand emotion, processing recent memory, olfaction, appetite, and emotional responses to food.

Lesions here can result in aggression, fearfulness, altered sexual behavior, or motivation

ANS Dysfunction

ANS influences all internal organs, blood vessels, and glands, controlling BP, HR, RR, Temp, metabolism, etc.

Constipation, erectile dysfunction, Horner's syndrome, vasovagal syncope, orthostatic hypotension, and postural tachycardia are all ANS dysfunctions that can be caused by outside pathology or primary damage.

Treated with pharmacological interventions.

Telencephalon

Cerebrum

Hippocampus

Basal Ganglia

Amygdala

Cerebrum

Area of the brain responsible for all voluntary activities of the body. Two hemispheres joined by corpus callosum.

Left Cerebral Hemisphere

Dominates in speech sounds & in understanding sequential, rational & analytical concepts

Right Cerebral Hemisphere

Controls left body,

Creative, Visual, facial recognition, visual, and musical traits, nonverbal communication, negative emotions, and concept comprehension

Frontal Lobe Functions

*Voluntary movement (primary cortex/precentral gyrus)

*Intellect

*Orientation

*Broca's area: Speech and concentration

*Personality, temper, judgment, reasoning, behavior, self-awareness, executive functions

Frontal Lobe Impairment

Contralateral weakness

Perseveration/inattention

Personality changes/antisocial behavior

Broca's Aphasia (expressive deficits)

Delayed/Poor intiation

Emotional Lability

Parietal Function

Sensory

Touch, kinesthesia, vibration, temp

Receives info from other areas of brain regarding senses and memory

Provides meaning or objects, interprets language and words, spatial/visual perception

Parietal Impairment

Dominant hemisphere (usually left): Agraphia, alexia, agnosia

Non-dominant hemisphere: Dressing apraxia, contstructional apraxia, anosognosia (unaware of deficit)

Contralateral sensory deficits

Impaired language comprehension and impaired taste

Temporal Function

-Hearing and smell

-Wernicke's area (ability to understand/produce meaningful speech, verbal and general memory)

Temporal Dysfunction

Learning deficits

Wernicke's Aphasia (receptive deficits)

Antisocial/aggressive behavior

Difficulty with facial recognition, memory loss, inability to categorize

Occipital Function

Visual processing--colors, light, shapes, 3D, judging distance

Occipital Impairment

-homonymous hemianopsia

-impaired extra ocular mvmt

-reading and writing impairment

-cortical blindness with bilat lobe involvement

Hippocampus

Responsible for forming/storing new memories and important to learning language. Embedded in lower temporal lobe.

Basal Ganglia

Gray matter masses in the white matter of cerebrum:

-Caudate

-Putamen

-Globus Pallidus

-Substantia Nigra

-Subthalamic Nuclei

Responsible for voluntary movement, regulation of autonomic movement, posture, tone, and motor responses.

Basal Ganglia Dysfunction

-Difficulty starting, stopping or sustaining movement

-Uncontrollable, repeated movements (shaking)

-Muscle spasms and muscle rigidity

-Parkinson's/Huntington's, Tourette's, ADD, OCD, addiction

Amygdala

Emotional and social processing. Processing of memory and formation of emotional memeory.

Thalamus

the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla and appropriate association cortex.

Coordinates sensory perception and movement.

Thalamic Pain Syndrome

a condition caused by damage to the thalamus resulting in burning or tingling sensations and possibly hypersensitivity to things that would not normally be painful such as light touch or temperature change.

Contralateral to thalamic lesion

Hypothalamus

Regulates homeostasis using hormones, controlling hunger, thirst, sexual behavior, sleeping, body temp.

Lesions produce impairments based on area of damage (obesity, sexual disinterest, poor temp control, diabetes insipidus)

Subthalamus

Regulates movements by skeletal muscles, associated with basal ganglia and substantia nigra.

Epithalamus

Contains pineal gland, which secretes melatonin and regulates internal clock.

Cerebellum

Control of finely coordinated movements. Coordination center, voluntary movement and balance. "Small brain."

Rapid alternating movements.

Damage to one side of cerebellum will produce ipsilateral impairment.

Lesions produce ataxia, nystagmus, tremors, hypermetria, poor coordination, and deficits in postural reflexes.

Pons

Regulates RR and associated with orientation of head in relation to auditory/visual stimuli.

Cranial nerves V-VIII originate from pons.

Medulla Oblongata

Connects to pons superiorly and spinal cord inferiorly.

Influences autonomic nervous activity and regulation of RR and HR. Reflex centers for vomiting, coughing, and sneezing.

Damage produces contralateral impairment.

Cranial nerves IX-XII originate from this structure.

Anterior Cerebral Artery

Supplies frontal lobe, and medial surface of frontal and parietal lobes.

Occlusion results in:

-Paraplegia

-Incontinence

-Personality changes

-Aphasia, Apraxia, Agraphia

-Perseveration

-Akinetic Mutism (mimicks catatonia)

Middle Cerebral Artery

Supplies most of outer cerebrum, basal ganglia

Most common site of CVA

Occlusion results in:

-Contralateral hemiplegia

-Global, Wernicke's, or Broca's Aphasia

-Homonymous Hemianopsia

-Apraxia

-Contralateral weakness and sensory loss of face/lower extremity

Posterior Cerebral Artery (PCA)

Supplies Occipital and inferior temporal lobes, subthalamic and basal nucleus, thalamus, and portion of midbrain.

Occlusion results in:

-Thalamic Pain syndrome

-Hemiballismus, ataxia, athetosis, choreiform movement

-Homonymous Hemianopsia

-Visual agnosia

-Cortical blindness

-Memory impairment

Vertebral-Basilar Artery

Supplies Cerebellum, medulla, pons, occipital cortex, and midbrain.

Occlusion results in:

-Locked-in syndrome, coma, vegetative state

-Wallenberg syndrome (secondary to lat medullary infarct) results in ataxia, verigo, ipsilateral facial pain/temp impairment and contralateral pain/temp impairment

-vertigo, nystagmus

-Dysphagia, Dysarthria, Syncope

Meningitis

Inflammation of the meninges. Bacterial meningitis is fatal in hours.

Sxs:

-Fever, headache, vomiting

-Complaints of stiff/painful neck

-Pain in lumbar area and posterior thigh

-Brudzinski's sign: flexion of neck facilitates flexion of hips and knees

-Kernig's sign: Pain with hip flexion combined with knee extension

-Sensitivity to light

Treatment with antibiotics and steroids, lumbar puncture for diagnosis

Hydrocephalus

Increase of CSF in ventricles of brain due to poor resorption, obstructed flow, or excessive CSF production. Can be congen, acquired, or idiopathic. Can be caused by spina bifida, choroid plexus neoplasm, cerebral palsy, tumor, meningitis, or encephalocele.

Sxs:

-Enlarged head or bulging fontanelles in infants

-Headache

-Vision and behavioral changes

-Seizures, altered appetite or vomiting

-Downward deviation of eyes ("sun-setting")

-Incontinence

Fasciculus cuneatus

Trunk, neck, and UE: Proprioception, 2 pt disc, graphesthesia

Fasciculus Gracilis

Trunk, LE: Proprioception, 2 pt disc, vibration, graphesthesia

Gracilis like the leg muscle

Spinocerebellar tract

Ipsilateral subconcious proprioception

Spinoreticular tract

Afferent pathway for reticular formation, influences level of consciousness.

Spinotectal tract

Afferent info for spinovisual reflexes, movement of eyes and head towards stimulus

Spinothalamic tract

pain and temperature

Corticospinal tract

Voluntary refined movements of distal extremities. Pyramidal. Damage to this tract results in positive Babinski sign, absent cremasteric reflex, and loss of fine motor skills

Reticulospinal tract

extrapyramidal motor tract responsible for facilitation or inhibition of voluntary and reflex activity through the influence on alpha and gamma motor neurons

Rubrospinal tract

Extrapyramidal motor tract responsible for motor input of gross postural tone, facilitating activity of flexor muscles, and inhibiting the activity of extensor muscles

Tectospinal tract

extrapyramidal motor tract responsible for contralateral postural muscle tone associated with auditory/visual stimuli

Vestibulospinal tract

Extrapyramidal tract for ipsilateral postural adjustments after head movements, extensor activation and flexor inhibition.

Damage to extrapyramidal tracts results in paralysis, hypertonicity, exaggerated DTRs, and clasp-knife reaction

Brown-Sequard Syndrome

Hemi-section of the cord

- ipsilateral (same side) spastic paralysis and loss of position sense

- contralateral (opposite side) loss of pain and thermal sense

A fibers

Peripheral nerve fibers.

Large size, myelinated with high conduction rates.

Sensory components:

-Primary muscle spindle endings (low threshold stretch)

-Secondary muscle spindle endings (change in length facilitates muscle contraction)

-GTOs: (interrupt muscle contractions on stretch of tendon)

Alpha: alpha motor neurons, muscle spindle primary endings, GTOs, touch

Beta: Touch, kinesthesia, muscle spindle secondary endings

Gamma: Touch, pressure, gamma motor neurons

Delta: Pain, Touch, pressure, temp

B Fibers

Peripheral nerve fiber

Medium diameter, myelinated, reasonably fast

Preganglionic fibers of autonomic nervous system

C fibers

Peripheral Nerve Fibers

Small diameter, unmyelinated, slow conduction rate. Postganglionic fibers.

C1

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Vertex of skull

Muscles innervated: None

Reflexes (if any): None

Paresthesias: None

C2 dermatome

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Temple/forehead/occiput

Muscles innervated: Longus colli, SCM, rectus capitis

Reflexes (if any): None

Paresthesias: None

C3

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Neck, posterior cheek, temporal area, mandible

Muscles innervated: Trap, Splenius capitis

Reflexes (if any): None

Paresthesias: Cheek, side of neck

C4

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Shoulder, clavicle, upper scap

Muscles innervated: Trap, Levator Scap

Reflexes (if any): None

Paresthesias: Clavicle and upper scap

C5

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Delt, Anterior arm to base of thumb

Muscles innervated: Supraspinatus, infraspinatus, delt, biceps

Reflexes (if any): Biceps, brachioradialis

Paresthesias: None

C6

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Anterior arm, radial side of hand to thumb and index finger

Muscles innervated: Biceps, supinator, wrist extensors

Reflexes (if any): Biceps, brachioradialis

Paresthesias: Thumb and index finger

C7

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Lateral arm/forearm to index, long and ring fingers

Muscles innervated: Triceps, wrist flexors

Reflexes (if any): Triceps

Paresthesias: Index, long, and ring fingers

C8

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Medial arm and forearm to long, ring, and middle fingers

Muscles innervated: Ulnar deviators, thumb EXT, thumb adductors

Reflexes (if any): None

Paresthesias: Little finger

T1

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Medial side of forearm to base of little finger

Muscles innervated: Finger abductors

Reflexes (if any): None

Paresthesias: None

T2

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Medial upper arm to medial elbow, pec and midscap areas

T3-T-12

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome:

-T3-6: upper thorax

-T5-7: Costal margin

-T8-T12: Abdomen and lumbar region

Muscles innervated: None

Reflexes (if any): None

Paresthesias: None

L1

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Back, over trochanter and groin

Muscles innervated: None

Reflexes (if any): None

Paresthesias: Groin

L2

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Front of thigh and knee

Muscles innervated: Psoas, hip adductors

Reflexes (if any): None

Paresthesias: Anterior thigh

L3

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Back, upper buttock, anterior thigh/knee, medial lower leg

Muscles innervated: Psoas, quads, thighs

Reflexes (if any): Knee jerk, prone knebend positive, pain on full SLR

Paresthesias: Medial knee, anterior lower leg

L4

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Medial buttock, lateral thigh, medial leg, dorsum of foot, big toe

Muscles innervated: Tibialis anterior, extensor hallucis

Reflexes (if any): Weak or absent knee jerk, SLR limited, side flexion limited

Paresthesias: Medial aspect of calf and ankle

L5

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Buttock, posterior/lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes

Muscles innervated: Extensor hallucis, peroneals, glute med, DFs

Reflexes (if any): SLR limited one side, neck flexion painful

Paresthesias:

S1

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Lateral and plantar aspect of foot

Muscles innervated: Calf and hamstrings, glute wasting, PFs

Reflexes (if any): Achilles reflex wek or absent

Paresthesias:

S2

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Buttock, thigh, posterior leg

Muscles innervated: Same as S1 +peroneals

Reflexes (if any): Achilles

Paresthesias: Lateral leg, knee, and heel

S3 dermatome

Dermatome: Groin, medial thigh to knee

S4

Dermatome:

Muscles innervated:

Reflexes (if any):

Paresthesias:

Dermatome: Perineum, genitals, lower sacrum

Muscles innervated: Bladder, rectum

Reflexes (if any): None

Paresthesias: Saddle area, genitals, anus, impotence, posterior herniation

Cranial Nerves

CN I: Olfactory (Sensory)

CN II: Optic (Sensory)

CN III: Oculomotor (Motor)

CN IV: Trochlear (Motor)

CN V: Trigeminal (Both)

CN VI: Abducens (Motor)

CN VII: Facial (Both)

CN VIII: Vestibulocochlear (Sensory)

CN IX: Glossopharyngeal (Both)

CN X: Vagus (Both)

CN XI: Accessory (Motor)

CN XII: Hypoglossal (Motor)

OOOTTAFVGVAH "Oh oh oh, to touch and feel"

SSMMBMBSBBMM "Some say marry money..."

CN I

Olfactory

Sensory: Smel

Test: Familiar odors (chocolate, coffee)

CN II

Optic

Sensory: Vision (central and peripheral vision)

Test: Visual fields

Common pathologies: Multiple sclerosis, Posterior CVA

CN III

Oculomotor

Motor: Levator of eyelid, superior/inferior/medial recti, inferior oblique

Test: Visual tracking (up, down, and medial gaze), and reaction to light

Common Pathologies: MS and Horner's

CN IV

Trochlear

Motor: Superior oblique

Test: Visual tracking (down and in)

CN V

Trigeminal

Sensory: Touch/pain on face, membranes of nose, sinuses, mouth and tongue

Motor: Mastication

Test: Corneal reflex, facial sensation, push down on chin

Common Pathologies: ALS, Trigeminal Neuralgia

CN VI

Abducens

Motor: Lateral rectus of eyeball

Test: Lateral gaze

CN VII

Facial

Sensory: Taste on anterior tongue

Motor: Facial muscles, lacrimal and sublingual glands

Test: Facial expressions, taste

Common Pathologies: ALS, Bell's Palsy, GB

CN VIII

Vestibulocochlear

Sensory: Hearing and balance

Test: Hear watch ticking, hearing tests, balance and coordination test

CN IX

Glossopharyngeal

Sensory: Posterior tongue sensation and taste, pharynx

Motor: Pharynx

Test: Gag reflex, swallowing

Common Pathologies: ALS, GB , Medullary Stroke

CN X

Vagus

Sensory: Pharynx, larynx, bronchi, taste in tongue/epiglottus

Motor: Muscles of palate, pharynx, larynx. Thoracic and ab viscera

Test: Gag reflex, ability to swallow, "Say ahhhhh"

CN XI

Accessory

Motor: SCM and Trap

Test: Resisted Shoulder shrug

CN XII

Hypoglossal

Motor: Muscles of tongue

Test: Tongue protrusion (if injured, tongue deviates towards injured side)

Muscle innervated by Lumbar Plexus

Psoas major, minor

Quadratus Lumborum

Muscles innervated by Sacral Plexus

Piriformis

Superior and inferior gemelli

Obturator Internus

Quadratus Femoris

Muscles innervated by tibial division of Sciatic Nerve

Semitendinosus

Semimembranosus

Biceps Femoris (long head)

Muscles innervated by Common Peroneal division of Sciatic Nerve

Biceps Femoris (short head)

Muscle innervated by Inferior Gluteal Nerve

Glute Max