Tissue
One or more similar cells having a specific function
Epithelial
Tissue that covers surfaces and line cavities
Epithelial tissue structure
- stratification/ stratified
- 1 layer= simple
- 2 or more layers= stratified
Epithelial tissue function
To cover a surface or line a cavity
Epithelial tissue types
- simple/stratified squamous
- simple/stratified cuboidal
- simple/stratified columnar
- pseudostratified columnar
Simple squamous
- scale like, flat, 1 layer
- involved with diffusion (high concentration to low concentration until everything is even), and filtration
- air sacs of the lungs, line blood vessels
- flexible for blood can flow through
Simple cuboidal
- square like, round neuclei in center, 1 layer
- filtration
-kidney tubules, surface of ovaries
Simple columnar
- column, elongated nuclei, 1 layer
- absorption of nutrients, excretion of mucus
- microvilli of digestive tract (lining), trachea
Pseudostratified columnar
- looks like multiple layers it is actually 1
- all cells attached to basement membrane
-secretion, movement across a surface
-lungs (moves debris out)
Stratification
Many layers, look at the surface
Stratified squamous
- more than one layer
-nuclei squished/flat
-protection - skin, lines mouth and throat
Stratified cuboidal
- more than 1 layer
- round nuclei
- protection
- sweat glands, memory glands, saliva
Stratified columnar
- more than 1 layer
-elongated nuclei - rare in humans
-parts of male urethra
Transitional
- could have 6-10 layers
- stretched = 3 layers
- at surface cells are dome shaped
- bladder, urethra and utterers
Connective tissue (CT) function
- connects tissue
- protection
-everywhere in the body
Connective Tissue (CT) structure
- Everywhere in the body
- cells
-fibroblasts, osteoblasts, hematopoietic
Connective Tissue (CT) fibers
Collagen- adds strength
Elastic fibers- elastin; stretch & recoil
Reticular fibers- collagen; provide a framework for soft organs
Connective Tissue (CT) Ground Substance
-fills space between cells and fibers
-help in diffusion of nutrients (especially O & CO2)
Loose CT
- not as dense
1. Areolar CT
2. Reticular CT
3. Adipose CT
Adipose CT
- fibroblasts (collect fat for protection/insulation
-found around kidneys & breasts - looks squamous
Dense/fibrous CT Structure
-can see a lot of fibers
-mostly collagen
Regular Dense CT
-collagen fibers are densely packed and parallel
- mainly in tendons
Irregular Dense CT
-Collagen fibers are random
- able to withstand stretching & Pressure.
- found in epidermis
-ligaments
Muscle tissue structure
-highly cellular
- actin/myosin filaments
