UWF NUR 3125 Patho - Module 4 - Full recap

Nervous system function

communication and control center; receives and interprets information to decide action

CNS parts

brain, spinal cord

CNS function

process and interpret information and decides what to do

PNS parts

nerves outside brain and spinal cord; sends sensory input to CNS and receives motor output from CNS

Neuron communication

using electrical signals (action potential) and chemical messengers (neurotransmitters)

action potential

electrical impulse along axon that triggers neurotransmitter release across synapse

EPSP

excitatory post-synaptic potential; encourages next neuron to fire

IPSP

inhibitory postsynaptic potential; stops or slows next neuron

resting potential

The neuron's inside is more negatively charged than the outside, creating a stable "ready" state before a signal is sent.

depolarization

The neuron's membrane becomes less negative as sodium ions rush in, starting an electrical signal

repolarization

The neuron returns to a negative internal charge as potassium ions exit, resetting after the signal passes

Brain need for oxygen and glucose

cannot store oxygen or glucose, so needs constant blood flow; if no o2 for 10 seconds, brain starts to fail (stroke and cardiac arrest)

frontal lobe

responsible for thinking and decision-making

parietal lobe

responsible for sensory perception (touch, pain, temperature)

temporal lobe

responsibe for hearing and memory

occipital lobe

responsible for vision

brainstem function

basic life function; breathing, heart rate, balance

midbrain function

relay station for sensory and motor messages

forebrain function

responsible for thinking, learning, emotions, and sensory interpretation

forebrain components

cerebrum, thalamus, hypothalamus

cerebellum function

Coordinates balance, posture, and smooth, precise movements

hypothalamus function

Regulates homeostasis (temperature, hunger, hormones) and links the nervous system with the endocrine system

thalamus function

Acts as the brain's relay station, sending sensory information to the correct areas of the cerebrum.

lobes of cerebrum

frontal, parietal, occipital, temporal

Cranial nerve I

olfactory (smell)

Cranial nerve II

optic nerve (vision)

Cranial Nerve III

oculomotor (most eye movements)

Cranial Nerve IV

trochlear (downward eye movements)

Cranial Nerve V

trigeminal nerve (facial sensation and chewing)

Cranial Nerve VI

abducens (lateral eye movement)

Cranial Nerve VII

facial (facial expressions/muscles)

Cranial Nerve VIII

vestibulocochlear nerve (hearing and balance)

Cranial Nerve IX

Glossopharyngeal (taste and swallowing)

Cranial Nerve X

vagus (breathing, heart rate)

Cranial Nerve XI

accessory nerve (neck and shoulder muscles)

Cranial Nerve XII

hypoglossal (tongue movement)

stretch reflexes

help keep muscle tone

withdrawl reflexes

protects from harm

autonomic nervous system

"automatic" division of PNS; has sympathetic and parasympathetic

Blood-brain barrier

protects brain by controlling what enters and exits the blood to keep brain environment stable

brain uses ____ of body oxygen and ___ of cardiac output

20%; 15%

movement pathway

Brain - UMN - LMN - NMJ - Muscle contraction

motor unit

one motor neuron and all the muscle fibers it innervates

neuron death

leads to denervation atrophy (muscle wasting)

UMN lesions

hyperreflexia, spastic, minimal atrophy (Ex. Stroke)

LMN lesions

hyporeflexia, flaccid, marked atrophy (ex. Guillain-barre syndrome)

Myasthenia Gravis

(NMJ disorder) antibodies destroy acetylcholine receptors → weaknessthat improves with rest

Parkinson's Disease

(basal ganglia disorder) decreased dopamine → resting tremor, slow movement(bradykinesia), rigidity

intention tremor

(cerebellar) rhythmic, involuntary shaking that becomes more pronounced as a person attempts to perform a purposeful, targeted movement

ataxia

(cerebellar) lack of muscle coordination

dysmetria

(cerebellar) overshoot movements; The inability to control the range of a movement and the force of muscular activity.

Peripheral neuropathy

numbness, burning pain

Radiculopathy

(nerve root compression): pain follows a dermatomal pattern

spinal cord injury effects

paralysis, respiratory compromise, unstable blood pressure,bladder/bowel dysfunction

Ischemia

reduced blood flow

Excitatory amino acid injury:

excess glutamate damages neurons

Cerebral edema

fluid accumulation (vasogenic or cytotoxic)

Increased Intracranial Pressure (ICP)

risk of brain herniation

Normal ICP

0-15 millimeters of mercury (mmHg)

Early Signs of Increased ICP

Headache• Vomiting without nausea• Decreased level of consciousness (earliest change)

Late Signs of increased ICP - Cushing's Triad

Increased systolic blood pressure• Decreased heart rate (bradycardia)• Irregular respirations

communicating hydrocephalus

impaired cerebrospinal fluid (CSF) absorption

non-communicating hydrocephalus

CSF flow obstruction

epidural hematoma

arterial bleed leading to rapid decline

subdural hematoma

venous bleed leading to slower symotoms

concussion

transient loss of consciousness and memory issues

Ischemic stroke:

blocked vessel (most common

hemorrhagic stroke

ruptured vessel

stroke risks

hypertension, atrial fibrillation, smoking, diabetes

Stroke Assessment

BEFAST - balance, eyes, face, arms, speech, time

Meningitis

Fever, headache, stiff neck (nuchal rigidity)• Positive Kernig and Brudzinski signs• Place on droplet precautions immediately

Encephalitis

Infection of brain tissue → altered mental status

Partial seziure

one brain region

Generalized seziures

both hemispheres

Status epilepticus:

prolonged seizure → emergency

Priority during seizure

protect airway, turn on side, do not restrain

Strain

injury to tendon

sprain

injury to ligament

dislocation

bones displaced from joint

loose bodies

fragments floating in joint space

fracture cause

sudden injury, stress, pathologic

greenstick fracture

one in which the bone is bent and only partially broken

comminuted fracture

fracture in which the bone is splintered or crushed

5 stages of bone healing

hematoma formation, cellular proliferation, callus formation, ossification, remodeling

fractures delayed healing

Infection• Poor blood flow• Malnutrition• Smoking• Corticosteroid use

compartment syndrome

involves the compression of nerves and blood vessels due to swelling within the enclosed space created by the fascia that separates groups of muscles

compartment syndrome symptoms

Hallmark: severe pain not relieved by opioid medications• Medical emergency → contact provider immediately• Do not elevate or apply ice (ATI emphasis)

rickets

Vitamin D deficiency in children

osteomalacia

disease marked by softening of the bone caused by calcium and vitamin D deficiency

osteomyelitis

infection of the bone; requires weeks of IV antibiotics

benign bone tumor

Osteochondroma

metastatic bone disease

most common bone cancer in adults

Growth plate injury

leads to risk of permanent limb shortening

internal/external toeing

A walking pattern where the feet point inward (intoeing) or outward (out-toeing), often due to rotational differences in the hips, legs, or feet.

Tibial Torsion

A twisting of the tibia (shinbone) that causes the feet to turn inward or outward during walking.

Femoral Torsion

An inward or outward twisting of the femur (thighbone) that affects hip rotation and foot alignment.

Bowlegs (Genu Varum)

A leg alignment where the knees stay apart when the ankles are together, creating a bowed appearance

Knock-Knees (Genu Valgum)

A leg alignment where the knees touch or angle inward while the ankles remain apart.

diagnostic test for developmental dysplasia of the hip

Signs:• Asymmetrical thigh folds• Limited abductionDiagnostic test: Ortolani maneuver

clubfoot

A congenital condition in which a baby’s foot is twisted inward and downward due to abnormal positioning of the bones, muscles, and tendons. corrected with serial casting