exam 1 - chapter 11 - pain and sensory regulation + eyes and ears

what is the definition of pain?

an uncomfortable phenomenon where stimuli send signals from inside or outside the body along neural pathways from the PNS to the CNS

what is nociception?

the processes of receiving messages from noxious stimuli

what are the four processes of pain perception?

transduction, transmission, perception, and modulation

what are the most notable sites of pain perception?

thalamus and cortex

what is transduction?

stimuli damages the tissue which activates nerve endings, facilitated by nociceptors

what is neurogenic inflammation?

mast cells degenerate, releasing inflammatory chemical mediators, increasing the induction of the action potential from nociceptors inducing chemical changes

the ______ the AP, the ______ the pain

greater

what is transmission?

relaying the message from the stimuli to the brain

what are the fibers in transmission and what are they responsible for?

• myelinated A-delta fibers are fast causing sharp sensation at time of injury

• unmyelinated C fibers are slow causing dull, burning, or aching pain

what is first order transmission?

transduction nociceptors → dorsal horn of the spine

what is second order transmission?

spinal cord → brain stem; axons of some second-order cells cross over to the opposite side of the spinal cord and project for long distances into the brainstem

what is third order transmission?

brainstem → thalamus, somatosensory cortex, and limbic system

what is perception?

complex integration of several processes resulting in interpretation of pain; takes place in the cortex, limbic system, and reticular system

what happens when blood is seen during perception?

pain might be interpreted as worse

what is modulation?

modification of neurotransmission activity to decrease the intensity; endogenous opioids released to inhibit pain sensation, gate control theory

how is the electrical signal for pain created?

transfer of sodium and potassium ions between extracellular and intracellular fluid

what is gate theory?

“gates” are built into the normal pain pathway that can modify the pain impulse’s movement to the brain

what is the neuromatrix theory?

our perception of pain is the result of a broad network of impulses that trigger somatic, limbic, thalamic, and cortical areas of the brain, and with stimulation, pain perception utilizes cognitive, affective, and sensory components influenced by a persons genetics and past; helps explain phantom limb pain and pain tolerance

what is referred pain?

sensation of pain that is not where the noxious stimuli is located

where are half of our sensory receptors?

in the eyes, responsible for visual input based on detecting visible light

where is visual input processed?

cerebral cortex

what are the parts and functions of the eye?

• palpebrae: protection, lubrication

• lacrimal caruncle: small, pink, ball shaped structure in inner corner; contains oil and sweat glands

• conjunctiva: thin, protective mucous membrane that covers the sclera

• lacrimal apparatus: produces and drains tears

• lacrimal glands: secrete tears to the excretory ducts

• lacrimal punctum: two small openings in which tears enter to drain into the lacrimal canals

• lacrimal canals: lead fluid to lacrimal sac and then to the nasolacrimal duct

what muscles coordinate eye movements?

superior rectus, superior oblique, medial rectus, lateral rectus, inferior rectus, and inferior oblique

what are the three layers (tunics) of the eye?

fibrous tunic (sclera and cornea), vascular tunic (choroid, ciliary body, and iris), and inner retina

what is the macula?

responsible for central vision, color vision, and fine detail; contains fovea centralis

what is the pain pathway?

nociceptors stimulated → afferent fibers (a delta, C) → synapse → cross over spinal cord → ascending tract to brain → RAS → somatic sensory areas

what is the OPQRSTU pain assessment?

onset, provocation/palliation, quality, region/radiation, severity, timing, and understanding

what is stevens-johnson syndrome & toxic epidermal necrolysis? how do you treat it?

a violent immune response that is a severe adverse reaction to a drug that causes acute destruction of epithelium of skin and mucous membranes; identify and stop offending drug

what is myopia?

inability to see far away objects clearly; nearsightedness

what is hyperopia?

inability to see nearby objects clearly; farsightedness

what is presbyopia?

gradual decrease in the ability to see nearby; affected by age

what is conjunctivitis?

inflammation of the conjunctiva

what is conjunctivitis pathophysiology?

exposure to virus, bacteria, fungi, allergen, or other irritant causes inflammation → blood vessel dilation and migration of immune cells to combat infection or remove irritants

what are conjunctivitis clinical manifestations?

bacterial → purulent discharge

viral → watery discharge/cold-like symptoms

allergic → itching, tearing, clear discharge

conjunctivitis management

if mild, no treatment or topical antibiotic eye drops; may need systemic antibiotics if caused by STD

conjunctivitis nursing considerations

transmitted via direct contact, so wash hands and don’t share towels

cataracts definition

lens becomes cloudy and interferes with light transmission

cataracts epidemiology

affects more than 24.4 million americans over 40

cataracts pathophysiology

proteins in the lens break down and clump together, which blocks or scatters light passing through the lens, causing blurry vision

cataracts etiology

aging, genetics, nutrition, smoking, diabetes, medications, UV radiation

cataracts clinical manifestations

halos around lights, reading difficulty, and progressive blurred vision that darkens over time

cataracts management

surgical replacement of lens

diabetic retinopathy definition

damage to the retina due to hyperglycemia

diabetic retinopathy epidemiology

global prevalence predicted to be 700 million by 2045

diabetic retinopathy pathophysiology

hyperglycemia → chronic activation of inflammatory pathways → release of cytokines, fluid, and blood into retinal tissue → ischemia/hypoxia of the retina

diabetic retinopathy clinical manifestations

initially asymptomatic → floaters, distortions, blurred vision

ophthalmic exam: microaneurysms

diabetic retinopathy management

control blood glucose, BP, and lipid levels; regular eye exams; laser therapy, surgery; injection of steroids into the eye or use of immunosuppressants

age-related macular degeneration definition

progressive eye condition usually affecting older adults

age-related macular degeneration epidemiology

200 million people globally, leading cause of vision loss globally

age-related macular degeneration risk factors

age, smoking, high BMI, high HDL levels, history of cataract surgery, vascular disease, exposure to blue light

age-related macular degeneration pathophysiology

nonneovascular AMD: “early stage”, deposits build up under retina and retinal cells gradually thin nd atrophy

neovascular AMD: less common, abnormal “leaky” blood vessels damage retinal tissue

age-related macular degeneration clinical manifestations

nonneovascular: asymptomatic, loss in visual acuity and function, decreased reading speed

neovascular: abrupt vision loss, can be severe and irreversible

age-related macular degeneration management

annual visual exams, avoid smoking/sun/blue light exposure, prevent CV disease

for neovascular AMD, intravitreal injections of anti-VGEF meds to lower risk, as well as corticosteroids and NSAIDs to reduce angiogenesis and inflammation

glaucoma types

primary open-angle glaucoma**, secondary open-angle glaucoma, and primary angle-closure glaucoma

primary open-angle glaucoma (POAG) definition

90% of cases, exact cause unknown

POAG risk factors

increased IOP, family history, female sex, race, age over 40, myopia

glaucoma epidemiology

2nd leading cause of blindness globally

glaucoma pathophysiology

• complex with various factors leading to optic nerve damage

• vascular dysfunction → ischemia to the optic nerve

• compression of the axons → dysfunction of the optic nerve

glaucoma clinical manifestations

asymptomatic in early stages; eventually develop patchy loss of peripheral vision then loss of central vision later

glaucoma management

• prevention: avoid eye injury, manage chronic conditions, healthy lifestyle

• early detection: regular eye exams

• treatment: lower IOP through meds (latanoprost, timolol maleate), laser therapy, and surgery

what is conduction hearing loss?

sound cannot get in to make the vibrations to transmit sound waves to cochlear nerve

how do you treat conduction hearing loss?

remove/fix obstruction

what is sensorineural hearing loss?

a disconnect within the inner ear prohibits sounds from being transmitted to the brain

what are ototoxic drugs?

drugs that can cause temporary or permanent hearing loss; antibiotics, analgesics, diuretics

what is tinnitus?

ringing in the ears; early sign of toxicity

what are some interventions for all kinds of hearing loss?

hearing aids, lip reading, ASL, cochlear implants, therapy with SLP

definition of otitis externa

inflammatory condition of external ear canal

otitis externa pathophysiology

usually bacterial, can be fungal infection → inflammatory response

otitis externa clinical manifestations

erythema and edema of ear canal, ear pain, purulent discharge, increased pain with movement of pinna

otitis externa management

acetaminophen or NSAIDs, topical antibiotic

otitis media definition

inflammation of middle ear (behind tympanic membrane)

otitis media epidemiology

most common childhood PCP visit

otitis media pathophysiology

dysfunction of the eustachian tube → edema, accumulation of pathogens from nasopharynx

otitis media clinical manifestations

otalgia, fever, irritability, anorexia, rubbing of the ears, crying, otorrhea

otitis media treatment

antibiotics are questioned because resistance may occur, so insertion of drainage tubes through TM are used to facilitate drainage

when do you use antibiotics for otitis media?

bilateral, unilateral with severe symptoms, or take oral amoxicillin

otosclerosis definition

excess bone in middle ear → stapes becomes fixed and blocks sound conduction to the cochlea; genetic, primarily in young females

otosclerosis clinical manifestation

hearing loss

otosclerosis treatment

hearing aids, surgical removal of the stapes with prosthetic replacement

ménière disease definition

cyclical attacks with period of relief in between, exact cause is unknown

ménière disease pathophysiology

excessive endolymph stretches membrane and interferes with hair cells in cochlea and vestibule; perilymph and endolymph may mix

ménière disease clinical manifestations

vertigo, fluctuating hearing loss, tinnitus, ear fullness

ménière disease management

prevention: avoid triggers (chocolate, caffeine, smoking); manage symptoms (N/V, inflammation); take vestibuulosuppresants

how to install ear drops

• patient upright, tilt head toward unaffected side

• pull down and back for kids, up and out for adults

• drops should be aimed at the side of the ear: avoid dropping directly on TM

• avoid instilling medications that are cold