Stratified Epithelium

stratified cuboidal

lines salivary gland ducts/sweat glands

uncommon types of epithelium (has a very limited distribution)

only 2 layers with a basal layer of cells often appearing incomplete

salivary gland swelling

pathology associated with stratified cuboidal epithelium

clinical condition that can result from blockage of a duct/ducts, so that saliva is not able to exit into the mouth

causes: salivary stone (calculus)- forms from salts contained in the saliva

symptoms: pain when chewing, swelling that worsens just before mealtime, bacteria could grow

• sometimes, a small stone may be ejected into the mouth without medical intervention

• removal of a stone may require surgery or lithotripsy treatment by focused, high-intensity acoustic pulsing

stratified columnar

located in the posterior surface of the eyelid, that is in contact with the surface of the eyeball, is lined by stratified columnar epithelium

also in exocrine glands

not common

trachoma

type of pink eye, stratified columnar in the palpebral conjunctiva of the eyelid

chronic conjunctivitis where the conjunctival epithelium surface suffers from inflammatory granulation caused by bacteria. often presents with keratoconjunctivitis

symptoms: tearing, discharge, photophobia, pain, and swelling of the eyelids, can lead to eye deformities, turned in eyelashes that scrape the cornea. (untreated- ulceration and infection in the cornea may occur which can lead to loss of vision if scarring happens in the center of the cornea)

• lymphocytes and macrophages help with inflammatory process in the underlying connective tissue

transitional epithelium

has the characteristic of being able to change shape to accommodate a volume change in the organ it lines

relaxed state= 4-6 layers

each surface cell appears umbrella/dome shaped

when stretched, the top dome-shaped cells become flat (squamous) and the epithelium becomes thinner

urothelium

location: kidney renal calyces, bladder, urethra,

urothelium

the epithelium lining the urinary tract including the bladder, ureter, and major calyces of the kidney

urothelial carcinoma

90%+ of bladder cancers originate in the transitional epithelium in the urinary system (most common is urinary bladder carcinoma)

generally in older men but may occur at any age

risks factors: smoking, exposure to radiation, infection by the parasite (schistosoma haematobium)

symptoms: painless gross hematuria (blood in pee that doesn’t hurt), frequency, urgency, dysuria (pain/burning)

treatment: transurethral resection (through the urethra), chemo, immunotherapy, radical cystectomy (remove bladder completely)

*high reoccurrence rate

cancer

uncontrolled growth, disorganization, lots of mitosis

keratinized stratified squamous

skin

layers of the skin

epidermis

dermis-connective tissue

subcutaneous tissue (hypodermis)- fat cells

2 parts of the skin

skin of the palms and soles (thick skin)

skin on most other body surfaces (thin skin)

histology of the skin

• epidermis- stratified squamous

• dermis- connective tissue

• top layer consists of dead cells (corneocytes) which lack a nuclei

• the cells of outer layers of the epithelium are flattened

• the middle most basal layers of cells are polyhedral or cuboidal

• only cells in the deppest layer are in contact with the basement membrane

• the interference between the epithelium and the underlying connective tissue is expanded dermal papille and rete ridges throughout most of the epithelium

psoriasis

pathology of keratinized stratified squamous. common chronic inflammatory skin disease typically chracterized by pink-to salmon-colored plaques with silver scales and sharp margins

symptoms and signs: itching, joint pain, nail pitting, nail discoloration

cause: genetic component, immunologic reactions

pathology: thickened epidermis, extensive overlying parakeratontic scales (keratin on top of epidermis with nuclei), neutrophils may migrate into the epidermis to form microabscesses , neutrophils may also form micropustules

• remission, partial remission, chronic

• common (3% of population)

• can be anywhere

microabsscesses

within the parakeratotic area of the stratum corneum layer

micropustules

located in the stratum granulosum and spinosum layers

bullous pemphigoid (BP)

pathology of kertainized stratified squamous. rare autoimmune skin condition characterized by fluid-filled blisters (bulla). typically affects older individuals

may initially manifest as itchy, scaly lesions in the nonbulbous phase

in the bulbous phase, tense fluid-filled blisters form preferentially on the flexor forearms, inner thighs, and lower abdomen

causes: uncertain, but it appears to be related to radiation exposure, medications, vaccinations

histology: the blister is formed by separation of the epidermis at the subepidermal interface. immunoflourescence microsopy shows linear deposits of C3 and/or IgG in the basement membrane

nonkeratinized stratified squamous

usually wet on its surface

found in the mouth, the oropharynx, the vocal cords, the vagina, and the esophagus

barrett syndrome

condition characterized by the development of intestinal metaplasia where the stratified squamous epithelium is replaced by simple columnar epithelium

causes: patients with long histories of gastroesophageal reflux (GERD) and heartburn

histological features: goblet cells, plasma cells (pink, lots of mitochondria, excentric nucleus, inflammatory cells (lymphocytes and plasma cells))

complications: patients have a high risk of developing cancer of the esophagus

commonly seen in middle aged white men