Epithelium and Glands Flashcards
4 Basic Tissue Types
- Epithelium
- Connective
- muscle
- Nervous
Functions of Epithelia
- Primary Function is a boundary layer through which movement of substances can be regulated; cover or line all body surfaces, except joint cavities
- protection
- line blood vessels
- absorption
- secretion
- sensation
- contractility
Avascular
Epithelia is not innervated by blood vessels
- all nutrients must pass from blood vessels through underlying connective tissue, or lamina propria
simple squamous
- Endothelium
- mesothelium
- parietal layer of bowmans capsule
- thin segment of loop of henle
- rete testis
- pulmonary alveoli
Simple cuboidal
- Thyroid
- choriod plexus
- ducts of many glands
- inner surace of the capsule of the lens
- covering surface of ovary
Simple Columnar
- surface epithelium of the stomach
- small and large intestine
- Gallbladder, excretory ducts of glands
- Uterus, oviducts
- Small bronchi of the lungs
- some paransal sinuses
Pseudostratified columnar
- Falsely stratified
- Large excretory ducts of glands, portions of male urethra
- epididymis
- Trachea, bronchi
- Eustachian Tube
Stratified squamous
- Based upon uppermost layer of cells
- Portions of tympanic cavity
- Buccal surface, esophagus, epiglotis, conjuctiva, cornea, vagine
- Epidermis of skin
- Gingiva, hard palate
Stratified cuboidal
- Ducts of sweat glands
Stratifed columnar
- cavernous urethra, fornix of conjunctiva, large excretory ducts of glands
- salivary gland duct
Transitional Epithelium
- Uppermost layer can change shape
- Urinary system - Bladder
Glandular epithelia
- Specialized function is secretion
- Parenchyma- The secretory cells of the gland
- Stroma- The connective tissue within the gland
Endocrine
- Secretory product passes directly into blood stream
- ex. hormones
exocrine
- Possess duct that convey the secretory product to the surface of the body or into the cavity of a hollow organ
Acinus and Duct of Exocrine Glands
- Acinus- secretory portion
- Duct- conducting portion
Classification of Exocrine Glands by Duct
- Simple- One unbranched duct
- Compound- Ducts Branch
Classification of Exocrine Glands by Secretory Portion
Simple - Tubular - Branched Tubular - Coiled Tubular - Acinar - Branched Acinar Compund - Tubular - Acinar - Tubuloacinar
Serous vs Mucous
- Serous - Aqueous
- Mucous- mucinous glycoproteins
- Serous stains darker than mucous
Merocrine Gland
Secretory vesicles bulge off
- most common
Apocrine Glands
- Portion of the cell breaks off and is secreted
- mammary glands
Holocrine Glands
- Whole cell is secreted, ruptures and releases contents
- Sebaceous glands of skin
Microvilli
- Brush Border
- Filled with actin filaments
- Has a terminal end of actin
- Glycocalyx- cell coat
Cilia
- Thicker brush appearance
- Longer than microvilli
- axoneme- made of microtubules, connected to basal body
- 9+2 arrangement of microtubules in axoneme
Stereocilia
- in Ductus epididymis
- Long Skinny microvilli
- Have actin like microvilli
- no axoneme structure
Microplicae
- help retain mucous in GI tract and other places
