Anatomy and Physiology: Epithelial Tissue and Muscle Tissue

Different layers, functions, and locations of where these cells are found in body

The primary purpose of all epithelial tissue

provide protection (shield inner tissue from harmful chemicals), permeability (controls what substances enter the body), sensation (detects changes in the environment), and secretion (releases chemicals from glands)

Examples of different body surfaces that are exposed to the outside environment and need the lining of epithelium tissue

lungs, mouth, stomach, (anything in digestive tract that comes into contact with the outside world), etc. 

3 Different Types of Layers in Epithelial Tissue

simple, pseudostratified, and stratified 

3 Main Types of Epithelial Tissue

squamous, cubodial, and columnar 

simple

single layer of epithelium tissue

pseudostratified

appears as multiple layers of epithelium tissue, but is really single 

stratified

multiple layers of epithelium tissue

squamous

flat, thin, scale and “squashed” like cells, greater in width than height; form protective linings throughout the body, found in skin and inner lining of organs like bladder and blood vessels

cubodial

cube like shape of cells, roughly equal in width and height; function in secretion and protection, found in kidney tubules, salivary glands, sweat glands, and the linings of airways 

columnar

tall, rectangular shaped cells, height is larger than width, nuclei located near base of cell; found in the stomach, intestines, hasal cavity, tr

transitional

constantly changing shape and layers; found exclusively in the urinary system, like the uterus, ureters, urethra 

ciliated

cells with cilia found in respiratory tract, like the trachea and bronchi

endocrine

RELEASES chemicals into blood or lymphatic vessels; hormones, pituitary gland, thyroid gland, adrenal gland

exocrine

SECRETE into ducts that empty to apical lining or lumen of an organ; sweat, mucus, saliva, salivary glands, pancreas, ovaries, testes

lumen

white space found above apical surface of the cell

apical surface

surface directly exposed to the lumen

epithelium

contains the cells

basement membrane

consists of proteins and located below the epithelium

basal surface

located below the epithelium and above the basement membrane

skeletal muscle

striated and multi nucleated (multiple nuclei in cell); used for voluntary movements

smooth muscle

spindle shaped, narrow ends, not strained;used for involuntary movements