pathology final 2

vision

detection of light by the eye and integration into consciousness of sensory signals produces

retina

innermost layer of the globe, light sensing

photoreceptors

structures within the retina that sense light and color wavelengths and translate them into electrical signals to be transmitted to the brain

rods

photoreceptors in the retina that discriminate light from dark

cones

photoreceptors in the retina that sense color (red, blue, green)

fovea

center of the macula in the retina, densely packed with cones, responsible for sharpest vision

macula

small and highly sensitive part of the retina responsible for details and central vision

visual pathway

nerve connections between photoreceptors and the brain (retina -\> optic nerve -\> optic chiasm -\> optic tracts -\> thalamus -\> visual cortex of occipital lobe)

orbit

the bony socket in the skull, protects the eyeball on all sides but the anterior

cornea

the transparent layer forming the front of the eye, turns into the sclera as you move internally around the eye

conjunctiva

Delicate membrane lining the eyelids and covering the anterior/superior portion of the eye

extraocular muscles

6 muscles that control the movement of the eye (superior rectus, inferior rectus, lateral rectus, medial rectus, superior oblique, inferior oblique)

strabismus

abnormal alignment of one eye - can be caused by neurologic disease or by weakness and shortening of an ocular muscle --\> can result in diplopia (double vision)

nystagmus

rapid, involuntary, rhythmic, repetitive motion of one or both eyes - can be caused by neurologic disease, disease of the inner ear, or drug toxicity

4 steps of normal vision

(1) light passes uninterrupted from the cornea to the retina, (2) the cornea and lens refract (bend) light to focus images on the retina (3) nerve signals pass along optic nerve and optic tracts in the brain to the visual cortex, (4) the visual cortex receives the image and (with other parts of the brain) assimilates it into a perception

myopia

globe is elongated --\> focal point is in front of the retina --\> nearsightedness

hyperopia

globe is foreshortened --\> focal point is behind the retina --\> farsightedness

presbyopia

with age, the lens stiffens and can no longer change shape --\> only distant rays focus on the retina --\> farsightedness

astigmatism

irregular curvature of the cornea --\> only some rays focus on the retina --\> misfocused images

cataract

clouded lens, major cause of poor vision and blindness around the world (can be caused by diabetes - hyperglycemia --\> sugar seeps into lens --\> converted to sorbitol --\> high osmotic pressure --\> attracts water)

hypertensive retinopathy

retinal arteriosclerosis --\> vessels become stiff and hard --\> can cause hemorrhage, blurred vision, blindness, etc

diabetic retinopathy

diabetes --\> hyperglycemia --\> inflammation, vessel thickening, hypoxia --\> macular edema (swelling of the retina) and retinal neovascularization (new vessels created because so many are dysfunctional) --\> gradually worsening vision --\> blindness - most common retinal vascular disease, found in 1/2 of pts with diabetes

glaucoma

a group of (preventable) eye conditions that can cause blindness - damaged optic nerve causes progressive vision loss, usually associated with increased intraocular pressure (ocular hypertension), there are 4 types

4 types of glaucoma

open-angle (idiopathic - drainage is normal, most common form, slow increase in pressure over time), closed-angle (drainage is blocked by inflammation, particles, etc - common), secondary (result of other conditions, many subtypes), congenital (present at birth)

conjunctivitis (pink eye)

inflammation of the conjunctiva - common in children, mild, contagious, can be caused by viral or bacterial infection

keratitis

inflammation of the cornea (caused by any infectious agent)

inner ear

contains cochlea for hearing and vestibular apparatus (semicircular canals and otolithic organs) for vestibular functions

semicircular canals

vestibular apparatus of the inner ear that is sensitive to rotational acceleration - contains endolymph (fluid) and ampulla (cartilage that contains crista - cupula (gelatinous membrane), hair cells, and supporting cells) - head movement --\> endolymph moves --\> cupula moves --\> hair cells move --\> vestibular signals generated

otolithic organs

vestibular apparatus of the inner ear that is sensitive to head position relative to gravity and to linear acceleration/deceleration - contains macula (otoliths, hair cells, gelatinous membrane, and supporting cells) - movement of gelatinous membrane and otoliths --\> moves hairs --\> vestibular signal generated

hair cells

receptors of the inner ear - bending determined the frequency of signals conveyed by the vestibular nerve

vertigo

internal or external spinning sensation (symptom, not a disease/diagnosis)

dizziness

imprecise term that could mean vertigo (internal or external spinning sensation), disequilibrium (feeling off balance/wobbly), lightheadedness (woozy, disconnected), or presyncope (about to faint)

Meniere's disease

increased fluid filling the vestibular apparatus AND cochlea --\> vertigo, fluctuating hearing loss, tinnitus (ringing) - idiopathic

conductive hearing loss

fluid in the middle ear, ear infections, etc --\> sounds cannot get through the outer and middle ear

sensorineural hearing loss

exposure to loud sounds, genetic factors, natural aging process, etc --\> damaged nerve pathways from the inner ear to the brain (90% of the hearing loss in adults)

epidermis

outermost layer of skin - basal cells on the bottom (can differentiate into melanocytes that produce skin pigment or keratinocytes), squamous cells (squashed keratinocytes), and dead keratin on top/exterior

dermis

middle layer of skin, includes papillary dermis (contains papules, looser) and reticular dermis (much larger, denser, contains glands/collagen fibers/other structures)

hypodermis

innermost layer of skin, aka subcutis/subcutaneous fat layer because it contains adipose tissue as well as nerves, veins, and arteries

fungal infections

diabetes --\> hyperglycemia --\> poor circulation (less nutrients, blood, water to skin) --\> dry, itchy, cracked skin --\> increased susceptibility to pathogens

ulcers

diabetes --\> hyperglycemia --\> poor circulation (less immune cells to site of injury) + diabetic neuropathy (decreased sensation) --\> this pathology forms over pressure areas (ex. heel of foot)

diabetic dermopathy

diabetes --\> hyperglycemia --\> poor circulation --\> brown scaly patches on the skin of the legs - goes away without treatment with proper control of blood glucose

AIDS (acquired immune deficiency syndrome)

causes measles-like rash in acute stage OR opportunistic infections such as kaposi sarcoma (opportunistic vascular neoplasm caused by a type of herpes virus) or general dermatitis

SLE (systemic lupus erthematosus)

autoimmune condition that causes lymphocyte (B-cell/T-cell) infiltration into the skin and inflammation of dermal-epidermal area - can cause the photosensitive skin (butterfly skin lesions), fatigue, joint pain, and fever

systemic sclerosis (scleroderma)

skin progressively becomes waxy, stiff, and shiny due to overproduction of collagen --\> skin thickness and tightness, other symptoms include joint pain or Raynaud's phenomenon

eczema

general term for an acute inflammatory reaction in the skin (descriptive term) - often used clinically interchangeably with atopic dermatitis

Atopic dermatitis (atopic eczema, eczema)

itchy inflammation of the skin caused by type 1 hypersensitivity, often associated with asthma and/or hay fever disorders, may be induced by drug and chemical allergens, symptoms include red swollen papules w/ crusting/scaling, skin thickening, variable dry patchy eruptions, and pruritus (itching)

contact dermatitis

skin inflammation caused by cosmetics, detergents, new clothes, jewelry, plants (poison ivy), etc - can be IRRITANT (most common, due to toxic material) or ALLERGIC (type IV hypersensitivity --\> itchy and irritated skin)

Seborrheic dermatitis (seborrheic eczema)

inflammatory skin condition that causes scaly patches and red skin, mainly on the scalp - dandruff (white flakes of dead skin) - also occurs on oily areas of the body (ex. face, upper chest, back) - idiopathic

psoriasis

immune system problem that triggers fast skin cells replacement (normal skin cells are replaced every 10-30 days --\> turns into every 3-4 days) - epidermal layer proliferation and chronic inflammation --\> red rash, scaly plaques, variable eruptions, etc - idiopathic

viral skin infections

warts (verruca vulgaris - caused by HPV) or cold sores (caused by HSV)

impetigo

common, highly contagious, superficial bacterial (staphylococcus or streptococcus) skin infection in kids --\> patches of red vesicles (small blisters or sores) --\> develop honey-colored crusts after burst

acne (propionibacterium acnes)

plugging of hair follicles with oil and dead skin cells --\> inflammation of sebaceous gland (the plugs themselves are NOT inflammatory) --\> whiteheads (pores have small, tight openings) and blackheads (large opening, revealing a surface layer of dark, oxidized melanin - not dirt!)

elastosis

degenerative changes in the dermal tissue with increased deposition of elastin material (can be due to age or excessive UV exposure)

solar elastosis (actinic elastosis)

photoaging due to excessive exposure to sunlight (UV radiation), new elastic materials form thick, dry, wrinkled skin

skin neoplasms

caused by prolonged chronic exposure to sunlight OR sometimes following burns or skin ulcers - types include malignant melanoma (MM), basal cell carcinoma (BCC), and squamous cell carcinoma (SCC)

malignant melanoma (MM)

begins as a proliferation of melanocytes in the basal cell layer of the epidermis (melanoma in situ - growth is confined to the epidermis only) --\> starts to spread by lymphatic and vascular invasion - first is RADIAL (HORIZONTAL) GROWTH (superficial spreading melanoma) followed by VERTICAL GROWTH (nodular melanoma) \-- most dangerous skin cancer

basal cell carcinoma (BCC)

begins in the basal cells (undifferentiated skin cells) - most common skin cancer

squamous cell carcinoma (SCC)

begins in the squamous cells (flattened surface cells) - second most common skin cancer, more aggressive

false

True or false: Severe symptoms are associated with melanoma.

b) congenital melanocytic nevi

Which of the following is not a major form of melanoma? a) nodular, b) congenital melanocytic nevi, c) superficial spreading, d) acral lentiginous

functions of the GI tract

ingestion (eating), secretion (release of enzymes, acids, etc), digestion (mechanical, chemical), motility (muscular contraction), absorption (uptake of nutrients), defecation (waste excretion)

signs/symptoms of GI disorder

anorexia, nausea, vomiting (emesis), dysphagia (difficulty swallowing), belching, flatulence, diarrhea (dysentery or steatorrhea), constipation

dysentery

low-volume, bloody, painful diarrhea

steatorrhea

type of diarrhea with fatty stool

upper GI (esophagus, stomach, upper intestine) hemorrhage

symptom is hematemesis (vomit with blood) that is red with fresh blood

stomach hemorrhage

symptoms are coffee ground-like hematemesis (vomit with blood) that is black due to gastric acid AND melena (black tarry stool with partially digested blood)

lower GI hemorrhage

symptom is hematochezia (red stool with fresh blood)

reflux esophagitis (gastroesophageal reflux disease/GERD)

inflammatory disease where stomach acid is in the esophagus due to an incompetent sphincter, hiatal hernia, or infection (AIDS) --\> esophagus inflammation, ulceration, and scarring --\> heartburn, dysphagia, hemorrhage

gastritis

inflammatory disease of the stomach - injurious agent (aspirin, ethanol), H. pylori, or fungal infection (in AIDS/immunocompromised) --\> inflammation/destruction of stomach secretory cells --\> ulcer of the stomach wall --\> loss of appetite, abnormal pain, hemorrhage, pernicious anemia due to Vitamin B12 deficiency

Gastric/Duodenal (peptic) ulcer

H. pylori, chronic NSAID use --\> erosion of stomach or duodenum mucosa epithelium with fibrosis and perforation --\> pain, hemorrhage, obstruction, carcinoma (if severe)

appendicitis

inflammation, ulceration, potential rupture of the appendix --\> pain, fever, perforation with peritonitis (inflammation of peritoneum --\> rupture), abscess or sepsis if rupture occurs

inflammatory bowel disease (IBD)

a general term for chronic inflammation of the digestive tract (ulcerative colitis and Crohn's disease) - symptoms include pain, diarrhea, weight loss, hemorrhage, exacerbation and remissions, and cancer (if severe) - idiopathic, may be autoimmune

ulcerative colitis

IBD limited to the colon, continuous inflammation, only occurs in the lining of the colon

Crohn's disease

IBD of the whole digestive tract, patchy inflammation, can occur in all the layers of the bowel walls

cirrhosis (liver disease)

hepatitis, alcohol abuse, nonalcoholic fatty liver disease --\> scarring (fibrosis) --\> liver dysfunction and failure --\> weakness, tiredness and weight loss in early stage --\> edema, ascites (fluid buildup in spaces within the abdominal region), and jaundice (too much bilirubin in the blood) in late stage

colon cancer

epithelial proliferation with invasion of colon wall and eventual metastasis --\> altered bowel movement, bleeding and fecal blood, iron-deficiency anemia - early is asymptomatic (most go undetected for a long time) - idiopathic, but risk factors include high-fat/low-fiber diet, genetics, chronic inflammation, etc

renal failure

ischemia, toxic injuries, chronic glomerulonephritis --\> degeneration/necrosis of renal tubule epithelial cells --\> oliguria (abnormally small amounts of urine), uremia (increased urea and waste in blood), and electrolyte imbalance

glomerulonephritis

inflammatory disease of the glomerulus - autoimmunity, toxins, metabolic waste --\> inflamed glomeruli with scarring in chronic cases --\> hematuria, proteinuria, hypertension, edema

cystitis

inflammatory disease of the bladder - urinary tract infection (UTI) usually --\> inflammation of the bladder mucosa wall --\> dysuria, urgency, frequency (more common in women)

renal calculi (kidney stones, nephrolithiasis, urolithiasis)

abnormal Ca2+ metabolism, dehydration, immobilization --\> mass in calyx, renal pelvis, upper ureter --\> intense pain, hematuria - treated by laser therapy or surgery

prostate cancer

increased androgens, genetics, etc --\> malignancy of prostate gland epithelial cells --\> hematuria, difficulty with urination

cervical cancer

HPV (main cause), STI --\> malignant tumor of the cervix --\> can be asymptomatic (pap test is important!), can cause irregular bleeding and pain

False

True or false: Occasionally having a drink of alcohol will put you at risk for developing liver cirrhosis.

D) x-ray

Which is NOT an appropriate test for liver cirrhosis? a) liver biopsy b) complete blood test c) liver function test d) x-ray

stem cell

an unspecialized/undifferentiated cell, no specific function yet - special properties: can divide over and over to produce new cells (self-renewable) AND can change into a specialized cell

labile tissue

tissue with short lifecycle, abundant stem cells, and high continuous regeneration activity (ex. bone marrow, epidermis, GI epithelium bronchial epithelium)

stable tissues

tissue with long lifecycle, abundant stem cells, and high regenerative activity with injury (default state of stem cells \= inactive until injury occurs) (ex. liver, kidney)

permanent tissues

tissues with no regeneration, fibrous repair (scarring) only, and very few stem cells (ex. brain, heart muscle, skeletal muscle)

atrophy

decreased size and function of a cell, tissue, organ, or body part - physiologic (due to AGE) or pathologic (result of disease of lack of normal physiologic support)

hypertrophy

increased size and function due to increased size of individual cells

hyperplasia

enlargement of tissue or organ due to increased number of cells

metaplasia

reversible change of one cell type into another due to chronic injury, adaptation to a new environment - generally benign

dysplasia

disordered cell growth, premalignant (precancerous) cell adaptation, increase amount of immature cells - 4 unusual properties \= abnormal cell shape, abnormal nucleus, increased chromatin, increased mitotic figures

acute inflammatory process

injury and vasodilation --\> mast cells and macrophages move to the site of injury --\> neutrophil adherence to vessel wall --\> neutrophil migration out of blood vessel to site of injury --\> exudate (mess of fluid that oozes out from blood vessel) and edema

vascular response to inflamation

initial inflammatory response - injury --\> temporary contraction of local arterioles (few seconds) --\> dilation --\> hyperemia (tissue becomes red and warm) --\> edema (plasma leaks from the blood into tissue)

mast cells

Cells found throughout the body that release chemicals (such as histamine) that promote inflammation

innate immunity

immunity present at birth, ability to attack any non-self substances, does not require prior exposure to non-self material, fast and broad

adaptive immunity

slow, programmable immunity - interacts with invading non-self material, learns its characteristics, manufactures a targeted, highly specific response (B-cell and T-cell immunity) - primary immune response is milder, about one week --\> secondary immune response is quicker with more antibodies and more cytotoxic T cells

natural killer (NK) cells

type of lymphocytes, innate capacity to recognize, attack, and kill virus-infected cells, no programming required, also has the ability to formulate immunological memory (adaptive) - play a role in both innate AND adaptive immunity

B-lymphocyte-mediated immunity

free antigen interacts with b-lymphocytes --\> produce plasma cells and memory B cells --\> plasma cells secrete Abs that attack and neutralize non-self antigens + memory B cells preprogrammed, ready to quickly multiple and release Abs (produced through clonal expression)