Epithelium and Glands (PPT based) Part II Flashcards
Nexus or communicating junctions
GAP JUNCTION
Couple adjacent cells metabolically and electrically
GAP JUNCTION
Common in certain tissues like CNS, cardiac and smooth muscles
GAP JUNCTION
Gap junction is composed of a channel-forming proteins (connexins) that assemble to form _______
connexons
Extracellular supporting structure
BASAL LAMINA
Produce by epithelium
BASAL LAMINA
Composed of type IV collagen, laminin, entacin, proteoglycans (mostly heparin sulfate)
BASAL LAMINA
Located at the boundary between epithelial cells and the underlying connective tissue
BASAL LAMINA
Specialized junctions that resemble ½ of the macula adherens
HEMIDESMOSOMES
Mediate adhesion of basal cell membrane to basal lamina
HEMIDESMOSOMES
Integrins on one side is attached to the plaque with keratin tonofilaments and on the other side attaches to laminin and collagen IV of BL
HEMIDESMOSOMES
Finger-like enfoldings functions to increase the surface area available for transport
BASAL PLASMA-MEMBRANE ENFOLDINGS
Common in ion-transporting epithelia
BASAL PLASMA-MEMBRANE ENFOLDINGS
Examples of basal plasma-membrane enfoldings:
Distal convoluted tubules, ducts in salivary glands
Compartmentalize mitochondria
BASAL PLASMA-MEMBRANE ENFOLDINGS
Function to bring ion pumps close to their energy supply (mitochondria)
BASAL PLASMA-MEMBRANE ENFOLDINGS
CLASSIFICATION OF EPITHELIA:
based on cell layer
Simple (one layer)
Stratified (more than one cell layer)
Classification of epithelia:
Based on cell morphology
Squamous
Cuboidal
Columnar
Other classification of epithelia:
Pseudostratified
Transitional
Shape of surface cells: flattened
SIMPLE SQUAMOUS
Sample locations: pulmonary alveoli, loop of Henle, parietal layer of Bowman’s capsule, inner and middle ears, blood and lymphatic vessels, pleural and peritoneal cavities
SIMPLE SQUAMOUS
Shape of surface cells: cuboidal
SIMPLE CUBOIDAL
Locations: ducts of many glands, covering of ovary, form kidney tubules
SIMPLE CUBOIDAL
Shape of surface cells: columnar
SIMPLE COLUMNAR
Locations: lining of oviducts, ductuli efferentes of testis, uterus, small bronchi, much of digestive tract, gallbladder, large ducts of some gland, Digestive tubes (STOMACH)
SIMPLE COLUMNAR
striated border; narrow finger-like cytoplasmic process
Microvilli
hair-like structure seen in uterus, oviducts, ductuli efferentes and small bronchi
Cilia
Shape of surface cells: all cells rest on basal lamina but not all reach epithelial surface; surface cells are columnar
PSEUDOSTRATIFIED
Locations: lining of most of trachea, primary bronchi, epididymis and ductus deferens, auditory tube, tympanic cavity, nasal cavity, lacrimal sac, male urethra, large excretory ducts
PSEUDOSTRATIFIED
Most type of pseudostratified columnar epithelium is ______ seen on the apical surface of the cells that reach the epithelial surface
ciliated
Shape of surface cells: flattened with nuclei
STRATIFIED SQUAMOUS, NONKERATINIZED
Locations: lining of mouth, epiglottis, esophagus, vocal folds, vagina
STRATIFIED SQUAMOUS, NONKERATINIZED
Shape of surface cells: flattened without nuclei
STRATIFIED SQUAMOUS, KERATINIZED
Locations: epidermis of skin
STRATIFIED SQUAMOUS, KERATINIZED
Shape of surface cells: cuboidal
Locations: ducts of sweat glands, Seminiferous tubules of Testes
STRATIFIED CUBOIDAL
Shape of surface cells: columnar
Locations: conjunctiva of eye, some large excretory ducts, portions of male urethra
STRATIFIED COLUMNAR
Shape of surface cells: dome-shaped (relaxed) flattened (distended)
Locations: lining of urinary tract from renal calyces to urethra
TRANSITIONAL
Specialized as organ of secretion or excretion
GLANDS
Formed when epithelial tissues grow down into the underlying connective tissue
GLANDS
ACCORDING TO SITE OF SECRETION:
Secrete into a duct or onto a surface
Exocrine
ACCORDING TO SITE OF SECRETION:
Most glands are of this type
Exocrine
ACCORDING TO SITE OF SECRETION:
Ductless; secrete into the blood
Endocrine
ACCORDING TO SITE OF SECRETION:
Examples are Thyroid gland, pituitary gland, testes, parathyroid, adrenal
Endocrine
ACCORDING TO MORPHOLOGY (based on duct branching):
Crypts of Lieberkuhn
Simple straight tubular
ACCORDING TO MORPHOLOGY (based on duct branching):
Sweat glands
Simple coiled tubular
ACCORDING TO MORPHOLOGY (based on duct branching):
Gastric glands, uterine glands
Simple branched tubular
ACCORDING TO MORPHOLOGY (based on duct branching):
Tarsal glands
Simple branched alveolar
ACCORDING TO MORPHOLOGY (based on duct branching):
Sebaceous gland
simple branched saccular
