lecture exam 2 Flashcards
the thin tissue forming the outer layer of a body’s surface and lining the alimentary canal and other hollow structures
epithelium
characteristics of epithelium
widespread- covers most of the body, inside and out.
- always has a free surface
- epithelial tissues usually lack a direct blood supply
- capable of mitosis
- cells usually packed tight, little intercellular material
- function in abosrption, secretion, and/or protecyion; usually highly inverted
membraneous epithelium are classified by _______,______,_____
shape, arrangement, function
singe layer of thin skin, flattened cells.
found where substaces need to move easily across a membrane (air sacs of lungs, walls of capallaries, bowmans capsule of kidneys)
simple squamos epithelium
single layer of cube-shaped cells.
found lining small ducts/tubeles that may have excretory, secretory, or absorptive functions (surface of ovaries, lining of smaller salivary gland, and sweat glands)
simple cubodial epithlium
single layer of elongated cells, with nucleus usually deep in the cell, near basement membrane
simple columnar epithelium
Found in the linings of uterus and uterine tubes and various organs of thedigestive tract (i.e., stomach, intestines, gall bladder), collecting ducts of kidneys
simple columnar epithelium
May be equipped with microvilli on free surface to increase absorptive properties, plus goblet cells, which secrete mucus onto free surface; or, with goblet cells and cilia on free surface to move fluids or particles along a passageway
simple columnar epithelium
A: Single layer of columnar epithelium in which cell nucleus is located at any level within the cell, not necessarily next to the basement membrane; all cells are anchored to thebasement membrane, but not all reach the free surface
b. Found in linings of upper respiratory system and lining some tubes of the male reproductive tract
c. May possess cilia and mucus-secreting goblet cells which facilitatetransport of material from one place to another
pseudostratified epithelium
a. Multiple layers of epithelial cells, of which the cells near the free surface are squamosal (i.e., thin and flattened); deeper layers tend to be cuboidal or columnar
b. Keratinized vs. non-keratinized
c. Makes upthe epidermis of the skin (keratinized), lines oral cavity, throat, esophagus, vagina, and anal canal (non-keratinized); mainly protective in function
startified squamos epithelium
a. Two-to-three layers of cuboidal epithelial cells, forming lining around a lumen
b. Limited to linings of larger glandular ducts (i.e., sweat glands, salivary glands, and pancreas); mainly protective in function
staratified cubodial epithelium
a. Several layers of cells, with columnar cells atthe free surface and cuboidal cells at the basement membrane
b. Found in parts of the pharynx and parts of the male urethra and ductusdeferens; mainly protective in function
stratified columnar epithelium
a. Consists of several layers of cuboidal cells, specialized to permit stretching and recoil
b. Forms inner lining of urinary bladder and part of ureters and urethra,adjacent to bladder
transitional epithellium
composed of epithelial cells specialized to produce and secrete substances into ducts or body fluids; usually located within, or composed of,columnar or cuboidal epithelium
glandular epithelium
secrete products (i.e., hormones) directly into tissue fluid; highly vascularized
endocrine glands
secrete products into ducts that open onto internal or external surfaces
Exocrine glands:
Unicellular (e.g., goblet cells)
ii.Multicellular
a.Duct shape: simple or compound
b’.Secretory structure shape: tubular or alveolar (i.e., sac-like)
types of exocrine glands
Merocrine: releases fluid cellular products through cell membranes without loss of cytoplasm (e.g., salivary glands)
a. Mucous membranes and mucus fluid
b. Serous membranes and serous fluid
types of secretions
ii. Apocrine: loses small portions of cell bodies during secretion (e.g., mammary glands)
iii. Holocrine: releases contents of entire cells filled with secretory products (e.g., sebaceous glands of skin)
types of secretions
A.Function: support/bind/protect other tissues/structures
B.General characteristics
1.Highly vascularized (except cartilageand dense regular connective tissue)
2.Cells capable of replication
3.Is not found on the free surfaces of body cavities or on body surface
4.Cells typically spaced far apart, with intervening space filled by an extracellular matrix
connective tissue
and osteocytes: responsible for secretion and maintenance of bone tissue matrix
Osteoblasts
secrete fibrous proteins into surrounding intercellular ground substance
Fibroblasts
specialized for fat storage
Adipocytes
responsible for secretion and maintenance of cartilage matrix
Chondroblasts and chondrocytes: