pain
an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
gate-control theory of pain
developed to explain the complexities of the pain phenomenon: different pain is transmitted via different nerves
nociceptors
Pain receptors
tonic receptors
bare nerve endings in skin, muscle, joints, arteries. Responds to chemical, mechanical, and thermal stimuli. Activated by abnormal stimulus.
endogenous opioids
chemicals produced naturally within the body that decreases or eliminate pain they closely resemble the actions of morphine
prostaglandins
produced in minute amounts in body tissues, behave differently in different tissues, have an imediate, short-term localiszed effect, involved in inflammation and pain, reproduction, changes in blood vessels, and blood clotting
bradykinins
polypeptides secreted by various body tissues that cause blood vessels to dilate when secreted by sweat glands to radiate excess heat, and dissolve blood clots (counter prostaglandins), responsible for inflammation and pain
histamine
a chemical released by basophil which plays an important role in inflammation. It increases the blood flow to the inflammed area and produces the cardinal signs of inflammation (heat, swelling, and redness)
direct excitation of nociceptors
Threshold depolarization from inflammatory mediators after tissue injury
Indirect excitation of nociceptors
threshold depolarization from inflammatory mediators after tissue injury
pain threshold
The lowest intensity of a stimulus that causes the subject to recognize pain.
perceptual dominance
intense pain at one location may increase pain threshold at another location
pain tolerance
amount of time or intensity of pain that an individual will endure before initiating overt pain responses
nociceptive pain
pain which is caused by damage to visceral or somatic tissue.
non-nociceptive pain
neuropathic pain (peripheral and central), pain that is elicited by damage to the peripheral or central nervous system. pain is described as burning, tingling, shooting, electric-like, and lightning-like.
neuropathic pain
elicited by damage to the peripheral or central nervous system. pain is described as burning, tingling, shooting, electric-like, and lightning-like.
acute pain
arises from sudden injury to the structures of the body- skin, muscles, viscera, bone and connective tissue. Includes type alpha-beta fibers, alpha-delta fibers, and type C fibers
alpha-beta fibers
normal, mechanical stimuli (fastest)
Alpha-delta fiber
myelinated (Fast) & carry sharp pain and cold stimuli
Type C fibers
unmyelinated and carry dull pain and heat/cold stimuli, histamine sensitive (itching)
Acute visceral
pain in the internal organs and abdomen. poorly localized due to lesser numbers of nociceptors
referred pain
pain that is present in an area removed or distant from its point of origin (visceral pain is poorly localized)
myofascial pain
in the fascia of the muscle (a very real pain) most common example-- fibromyalgia, occurs for a lot of different reasons.
complex regional pain syndrome
pain that develops 1-2 weeks after an injury to an arm or a leg, a heart attack, stroke, or other medical problem. involves inflammatory cytokine response
phantom limb pain
Perceived sensation of pain from an amputated limb; overactivity of the dorsal horn neurons on the side of the amputated limb may create a false feeling that the pain is emanating from the amputated limb.
blepharitis
inflammation of the eyelid
hordeolum (stye)
small purulent inflammatory infection of a sebaceous gland of the eyelid
chalazion
chronic nodular inflammation of a meibomian gland, usually the result of a blocked duct; commonly presents as a swelling on the upper or lower eyelid
keratitis
infection of the cornea, inflammation of the cornea causing watery painful eyes and blurred vision
acute bacterial conjunctivitis
pink eye" mucopurulent drainage from one or both eyes, Acute minimal pain of eye with copious purulent discharge
allergic conjunctivitis
AN ACUTE INTERMITTENT OR CHRONIC INFLAMMATION THAT MAY BE ASSOCIATED WITH ASTHMA AND ATOPIC DERMATITIS WITH SYMPTOMS OF TEARING ITCHING REDNESS AND STRINGY DISCHARGE (watery discharge)
viral conjunctivitis
eye irritations due to Herpes simplex types 1 & 2, Adenovirus, or viruses affecting upper respiratory tract
strabismus
crossed eyes; a condition of eye misalignment caused by intraocular muscle imbalance
diplopia
double vision
nystagmus
an involuntary, constant, rhythmic movement of the eyeball that can be congenital or caused by a neurological injury(pendular- caused by CNS lesions)
jerk nystagmus
eye drift followed by fast corrections
amblyopia
reduced vision in one eye caused by disuse or misuse associated with strabismus, unequal refractive errors, or otherwise impaired vision; also called lazy eye
scotoma
an isolated area of diminished vision within the visual field
retrobulbar neuritis
inflammation of the optic nerve behind the eye: common in MS
cataract
clouding of the natural lens of the eye
retinitis pigmentosa
hereditary, progressive disease marked by night blindness with atrophy and retinal pigment changes
papilledema
swelling of the optic disc from increased intracranial pressure; seen in Guillain-Barre syndrome, brain tumor, intracerebral hemorrhage
dark adaptation
the process by which visual receptors become as sharp as they can in darkness. both rods and cones adjust but ultimately rods are more effective in darkness
glaucoma
disease of the eye characterized by increased intraocular pressure that results in damage to the optic nerve, producing defects in vision
age-related macular degeneration
breakdown or thinning of the tissues in the macula, resulting in partial or complete loss of central vision