Anatomy Ch. 4
4 types of tissue
1. Epithelial 2. Connective 3. Muscle 4. Neural
4 functions of epithelial tissue
1. Provide Physical Protection 2. Control Permeability 3. Provide Sensation 4. Produce Specialized Secretions (glandular epithelium)
What are the 2 layers of Epithelia
1. simple 2. startified
What are the 3 shapes of epithelia
1. squamous 2. cuboidal 3. columnar
Simple Cuboidal Epithelium Locations
: Glands; ducts; portions of kidney tubules; thyroid gland
Epithelia are replaced by division of germinative cells (stem cells) Near basement membrane
Epithelial Maintenance and Repair
Produce secretions Onto epithelial surfaces Through *ducts* Release chemical substances through ducts to outside the body or onto another surface within the body
Exocrine glands
True or false, unicellular glands have ducts?
False
Structures that produce secretions
Glands
Attach cells to the basal lamina Half a desmosomes
Hemidesmosomes
Entire cell is lost, continual regeneration of cells
Holocrine secretion
Help cells stick together, secretions, Glycosaminoglycans
Hyaluronan (hyaluronic acid)
Secretions of Proteoglycans
Intercellular cement
Simple Cuboidal Epithelium Functions
Limited protection, secretion, absorption
Pseudostratified Ciliated Columnar Epithelium Locations
Lining of nasal cavity, trachea, and bronchi; portions of male reproductive tract
Stratified Cuboidal Epithelium Location
Lining of some ducts (rare)
Simple Columnar Epithelium Locations
Lining of stomach, intestine, gallbladder, uterine tubes, and collecting ducts of kidneys
Producing secretions in a vesicular format, and they transport the secretion to the surface of the cells, and release them by exocytosis
Merocrine secretion
Stratified Columnar Epithelium Locations
Small areas of the pharynx, epiglottis, anus, mammary glands, salivary gland ducts, and urethra
thin and flat
Squamous epithelia
several layers of cells
Stratified epithelium
Stratified Squamous Epithelium Locations
Surface of skin; lining of mouth, throat, esophagus, rectum, anus, and vagina
Why are there so many types of tissues
Tissue structure is adapted to the function of their region
Branched multicellular glands
several secretory areas sharing one duct
Epithelia is classified by ___ and ___
shape, layers
How much ___ is applied to the epithelium depends on how the transitional epithelium looks
stress/stretch
The duct structure of multicellular glands is either Simple (___) or Compound (___)
undivided-straight, divided-branched
Mucous (goblet) cells are the only ___
unicellular exocrine glands
Transitional Epithelium Locations
Urinary bladder; renal pelvis; ureters
Allow rapid communication Are held together by channel proteins (junctional proteins, connexons) Allow ions to pass Coordinate contractions in heart muscle
gap junctions
The types of secretions are based on their
method of secretion
Unicellular exocrine glands secrete ___
mucus
Layers of cells covering internal or external surfaces
Epithelia
Nonattached surface of Epithelial tissue
apical
square shaped
Cuboidal epithelia
Vesicles accumulate near the appical surface of the cell, as they gather the appical portion of the cell is pinched off, exocytosisportion of the cell is damaged and needs to regenerate
Apocrine secretion
proetins that cross cell membrane and hook to proteins of other cells, transmembrane proteins
CAMs (cell adhesion molecules)
Form bonds with other cells or extracellular material
Cell junctions
another name for mixed exocrine glands
Cerro mucinous glands
Cellularity (cell junctions) Polarity (apical and basal surfaces) Attachment (basement membrane or basal lamina) Avascularity Innervate Regeneration
Characteristics of Epithelia
Thin layer Secreted by epithelia Barrier to proteins (attachment to basement membrane)
Clear layer (lamina lucida)
tall, slender rectangles
Columnar epithelia
________ are proteins that connect adjacent cells at a gap junction
Connexins
Thick fibers Produced by connective tissue Strength and filtration (attachment to basement membrane)
Dense layer (lamina densa)
CAMs, dense areas, and intercellular cement Tie cells together, allow bending and twisting Found in small localized areas Tissues under stress i.e. skin
Desmosomes
Release hormones Into interstitial fluid No ducts Release chemical substances directly into the bloodstream or tissues of the body; surrounding tissue
Endocrine glands
Simple Squamous Epithelium Locations
Mesothelia lining ventral body cavities; endothelia lining heart; and blood vessels; portions of kidney tubules (thin sections of nephron loops); inner lining of cornea; alveoli of lungs
Both serous and mucous
Mixed exocrine glands
Thick ,slippery, secrete mucins
Mucous glands
Transitional Epithelium Functions
Permits expansion and recoil after stretching
Stratified Columnar Epithelium Functions
Protection
Simple Columnar Epithelium Functions
Protection, secretion, absorption
Stratified Cuboidal Epithelium Function
Protection, secretion, absorption
Pseudostratified Ciliated Columnar Epithelium Functions
Protection, secretion, move mucus with cilia
Stratified Squamous Epithelium Functions
Provides physical protection against abrasion, pathogens, and chemical attack
Made up on a single layer of cells, all cells reach the basement membrane
Pseudostratified
Simple Squamous Epithelium Functions
Reduces friction; controls vessel permeability; performs; absorption and secretion
Thin, watery secretions, enzyme rich
Serous glands
3 exocrine glands
Serous, Mucous, Mixed exocrine
single layer of cells
Simple epithelium
Attached surface of Epithelial tissue
basal
Germinative cells
divide continually to produce new epithelial cells
The tissue that always has an apical and a basal surface is ________ tissue.
epithelial
Pseudo
false
Glands that secrete their product by the bursting of cells are ________ glands
holocrine
The basal layer is broken up into two parts the ___ (closer to the epithelium), and the ___ (closer to the connective tissue)
lamina lucida, lamina densa
the body's most delicate type of epithelium is
simple squamous
Between two plasma membranes Adhesion belt attaches to terminal web Prevents passage of water and solutes (water tight barrier) Isolates wastes in the lumen Made up of row proteins within one cell membrane that line up with adjacent row proteins thus limiting intercellular movement
tight junctions
Are collections of cells and cell products that perform specific, limited functions
tissue
For multishaped cells, whichever cell shape is on the ___ determines its shape type
top/closest to the surface
The shape of secretory portion of the f multicellular glands is either Tubular (___) or Alveolar/acinar (___)
tube shaped, round blind pockets