Basics Of Epithelium PDF

BASICS OF EPITHELIUM DIMARUN HANEF D. MACABUNBUN JR. SIMPLE EPITHILIA Thin, scale like Alveoli, endothelium of the heart and blood vessels Lymphatic and thyroid Diffusion, secretion, lubrication and filtration STRATIFIED SQUAMOUS Multiple scale like Skin, oral cavity, esophagu...

BASICS OF EPITHELIUM DIMARUN HANEF D. MACABUNBUN JR. SIMPLE EPITHILIA Thin, scale like Alveoli, endothelium of the heart and blood vessels Lymphatic and thyroid Diffusion, secretion, lubrication and filtration STRATIFIED SQUAMOUS Multiple scale like Skin, oral cavity, esophagus, vagina Against abrasion SIMPLE CUBOIDAL Square, equal H and W, Nucleus is at center Kidney tubules and glands Absorbs and secretes substances Transport with no leakage Stratified Cuboidal Salivary glands, sweat gland ducts, mammary gland and prostate gland. To transport and protect it Simple Columnar Rectangular, H>W, with or without cila Ciliated is the uterine (ft) Bronchi and uterus Non ciliated is the digestive tract. Absorption, secretion of mucous and enzymes, duodenum, Stratified Columnar Conjunctivae of eye, uterus, pharynx Secretes chemical for protection Protection and transport. Pseudostratified Columnar It looks stratified but all cell contacts with BM Trachea and upper respiratory tracts Secrets and moves mucus Stratified Squamous 1. keratinized stratified squamous 2. Non – Keratinized stratified squamous When there is a lot of abrasion like the skin and gums. Transitional (Urothelium) Dome shaped Urethra and ureter Specialized for stretching, expand Looks stratified Epithelium specialization Epithelium must adhere and communicate Leak proof, attach BM, Flexible They need to communicate to control the transport of ion, water, and proteins Tight Junction (Zonula) It completely encircles the cell. To seal between cells Allow transcellular instead of paracellular. More in bladder, less permeability in contrast with kidney. It set up the apical and basal layer. Occludens, ZO proteins Sjorgrens syndrome/ clastrodium perfringens Adherens junction Zonula adherens (anchors cells to neighbors) Like TJ with belt Stabilized and strengthen the bond to hold cells Cadherens bind to catenin link to actin Desmosomes (Maculla adherens) Structure in one cell is identical in the other cell side With extending filamments Large cadherens (Desmogleins, Desmoplakin) Keratin intermediate filaments Mechanical stress (heart) Hemidesmosomes Half desmosomes (integrins) keratin ( not same w/ D) Focal adhesion junction (direct link to actin) Gap Junction Communicate cells Exchange of nutrients and signal molecules Connexons (connexin) For a highly coordinated manner like heart contraction Heartache, calloused skin, tooth Transcellular vs Paracellular Simple diffusion Aquaporin Gated ion Antiporter Symporter (O2 CO2 and NA/K ATPase) Aquaporins Water pass and determined by the relative amount Transcellular (passive) Parascellular (ion channel) Absorption (Na+ absorption) Apical 1. ENacC Na Channel Basal 2. Na+/K+ ATPase 3. K+ Channel *Cl V PC *H2O v TC/PC Na+ low in Na+ High EX K+ High in Secretion Blood/ Basal layer/ Out of the lumens Cl- secretion Apical pole 1. CFTR channel 2. Other Cl- channel Basal layer 1. NKCCT 2. Ion exchanger 3. Na+/HCO3 Exchanger Na paracellular CFTR and fluid export