epithelial tissue + fun facts

the most common skin condition

acne

how many skin cells do you lose every minute

30,000-40,000

how much of your body weight is muscle

40-50%

how long can nervous tissue last without oxygen

3-5 minutes

how long without oxygen until you faint

8-10 seconds

most common tissue injuries

contusion, sprains, strains

tissue

groups of cells with similar structure and function

histology

the study of tissues

organ

two or more types of tissues

et location

• body coverings

• body linings

• glandular tissues

et function

• protection

• absorption and filtration

• secretion

et characteristics

• cells fit closely together

• tissue layer always has one free surface

• lower surface is bound by basement membrane

• avascular (no blood supply)

• regenerates easily if well nourished

simple squamos

• single layer of flat cells

• usually forms membranes

  • lines body cavities

  • lines lungs (alveoli)

simple cuboidal

• single layer of cube like cells

• common in glands and their ducts

• covers ovaries and forms wall of kidney tubules

simple columnar

• single layer of tall cells

• called goblet cells (produce mucus)

• lines digestive tract

psuedo-stratified columnar

• single layer, but looks like two

• ciliated; found in trachea

stratified squamos

• cells at free end are flattened

• found as a protective covering where friction is common

  • skin, mouth, esophagus

stratified cuboidal

• two layers of cuboidal cells

• rare in human body

• found mainly in the ducts of large glands

stratified columnar

• surface cells are columnar, cells underneath vary in size and shape

• rare in human body

• found mainly in ducts of large glands

transitional epithelium

• shape of cells depend on the amount of stretching

• lines organs of the urinary system (bladder)

glandular epithelium (endocrine)

• ductless

• secretions are hormones

glands

one or more cells that secretes a particular product

glandular epithelium (exocrine)

• empty through ducts to epithelial surface

• sweat and oil glands