epithelial tissue

What are the four types of tissue?

1. epithelial tissue

2. Nervous tissue

3. Connective tissue

4. Muscle tissue

Tissue is composed of what?

Cell + ECM

What are the rules of a tissue?

1. Cell type = tissue function

2. Shape of ECM= tissue function

3. Ratio of cell and ECM depends on function

CELL,SHAPE,RATIO ALL DEPEND ON FUNCTION!!!

1. epithelial are…

Sheets of packed cells

What are the two types of epithelial tissue

1. Membranous membrane: lining/covering

Glandular Membrane:

glands

What is membranous membrane?

Lining/covering

What is Glandular membrane?

> GLANDS

> Two types exocrine & endocrine

Endocrine function of Glandular membrane?

Secretion via hormones → blood

Exocrine function of Glandular membrane?

secretion via ducts (Sweating saliva)

exocrine multicellular?

(Glandular membrane)

Invaginates into connective tissue

exocrine unicellular?

(Glandular membrane)

goblet cells: mucin prouder + water = mucus

Apical surface?

-top surface

-faces lumen or open environment

-used 2 indentify cell shape and type

Basal surface

-deeper layer

-connects to basement membrane

epithelial tissue characteristics

-avascular(no blood supply)

>AS RESULT: HIGH REGEN/DEATH

-cells connected via intercellular junctions

Why must an epithelial tissue must be with a Connective tissue?

-epithelial tissue is avascular, as result connective tissue need to be there to support nutrients

Stratified

1 layer and up

>Not all cells touch basement membrane

pseudostratified

• appear to be more than layer but

• ALL CELLS MUST TOUCH BASEMENT MEMBRANE

• not all cells touch Apical surface

Columnar

Secretion/ absorption

> W < H

cuboidal

Secretion/ absorption

> W ~ H

Squamous

Diffusion/Protection

>W > H

Transitional(umbrella)

Stretch, change shape

Simple squamous

Location: kidney glomeruli, air sac of lungs, lining of heart and vessels, serous membrane

Function: Diffusion/ Protection

> Secretes lubricants fluids in serous membrane

Simple cuboidal

Location: kidney tubules, ducts, ovary

Function: Absorption/ Secretion

>absorb substances and excrete waste

Simple columnar

Location: digestive tract, gallbladder, small bronchi

Function: Absorption/ Secretion

>absorb substances and excrete waste

Stratified squamous:

Location: epidermis of skin, lining of esophagus, mouth, vagina, anus

Function: protection

>Limits the substance that enters the body

pseudostratified

Location: respiratory tract, part of penile reproductive tract

Function: produce mucus and protect from antigen/ foreign cells

GOBLET CELLS AND CILLIA

What are the two cells that do Surface specialization?

1. CILLIA CELLS

2. GOBLET CELLS

Goblet cells

Mucus producer

>lubricates: protect

Cillia cells

Move mucus across cell

epithelial tissue Func?

Lining, covering, secretion

nervous tissue func?

Commutation center

Muscle tissue func

Movement

Connective tissue func?

ACTS LIKE A FRIEND

> support and protect