Tissues

• Group of cells similar in structure and function

• 4 types:

- epithelial (covering)

-connective(support)

-muscle (movement)

-nerve (control)

Epithelia connective muscle nerve

Epithelia Tissue

• Composed entirely of cells• Sheets of cells held together by tight

junctions and desemomes• Form boundaries between environments• Regenerative-rapidly replace lost cells• Avascular but intervated-contains no

blood vessels but supplied by nerve fibers• 6 functions:

- protection, absorption, filtration, excretion, secretion, sensory reception

• classifications:

-#of layers-simple or squamos

-shape- squamos, cuboidal, columnar

Simple stratified tissues

Like epithelia tissue, a brick wall forms a boundary between two different environments

Epithelia Simple

• Main jobs:

-secretion, absorption, filtration

• Single layer

• Very thin=little protection

• 3 types:

-simple squamos, simple cuboidal, simple columnar

Simple squamos simple cuboidal simple columnar epithelia tissues

Simple Squamos Epithelium

• Single layer of flattened cells w/ discs shaped nuclei (resembles fried egg)

• Functions:

-diffusion and filtration• Allows passage of material where

protection not needed• Special types :

-Endothelium “inner covering”

*Provide slick, friction reducing lining in vessel and heart

-Mesothelium “middle covering”

*found in serous membranes of ventral body cavity

Simple cuboidal simple columnar epithelia simple epithelia tissue

Simple Cuboidal Epithelium

• Single layer of cells tall as they are wide

• Look like string of dark beads

• Functions:

- secretion and absorption

• Forms walls on small duct glands and kidney tubules

Simple squamos simple columnar epithelia simple epithelia tissues

Simple Coulumnar Epithelium

• align like soldiers to form single layer of tall, closely packed cells

• Lines digestive tract from stomach through rectum

• Two main functions:

-absorption and secretion• Dual functions ideal for digestive tract

-dense microvilli on apical surface of absorptive cells and goblet cells which separate lubricating mucus

• Cilia on free surface allow substance to move through passageways

• Special type:

-pseudostratified columnar

* vary in height

* nuclei lie at different layers = false impression of several layers

*same functions as simple columnar and line respitory tract

Simple squamos simpe cuboidal epithelia simple epithelia tissues

Simple columnar

Psuedostratified epithelium

Stratified epithelia

• Contains two or more layers• Regenerate from below:

-basal cells divide and push to replace• More durable than simple epithelia• Major role is protection• 4 types:

- stratified squamos

- stratified cuboidal

- stratified columnar

- transitional epithelium

Stratified cuboidal stratified columnar transitional stratified squamos epithelia tissue

Stratified Squamos Epithelium

• Most wide spread of 4 types• Several thick layers=perfect for

protection• Found areas subject to wear and

tear• Depends on diffusion of nutrients• Forms external part of skin to

every body opening connected to skin

• Outer layer of skin keratinized

-tough protective protien

Stratified cuboidal stratified columnar transitional epithelia stratified epithelia tissue

Stratified Cuboidal Epithelium

• Very rare

• Found in large ducts

• Usually has two layers

Stratified columnar stratified squamos transitional stratified epithelia epithelia tissues

Stratified columnar epithelium

• Not common

• Found in pharynx, male urethra, and glandular ducts

• Only apical layer is columnar

Stratified cuboidal stratified squamos transitional stratified epithelia epithelia tissues

Transitional Epithelium

• Forms lining in urinary organs• Basal layer cells:

- cuboidal or columnar• Apical layer cells:

- vary depending on degree of distention

• Cells change shape to allow urine to be stored

Stratified squamos stratified cuboidal stratified columnar stratified epithelium epithelia tissues

Connective Tissue

• Found everywhere in body• Most abundent and distributed of primary

tissues• Functions:

- binding and support, protection, insulation, and transportation

• Characteristics:

- common orgin, degrees of vascularity, extracellular matrix,

• Main elements:

-ground substance

*fills space between cells

-fibers

*provide support

-cells

*fundamental in connective tissue• 4 types

- proper, cartilage, bone tissue, and blodd

proper catilage bone tissue blood tissues

Like connective tissue, chain links are used to bind and support

Connective Tissue Proper

• 2 subclasses

-loose connective tissue

-dense connective tissue

• Except for bone, cartilage, and blood, all connective tissue belongs in this class

Loose tissue dense tissue connective tissues

Loose Connective Tissues

• 3 types

- areolar

-adipose

-reticular

Areolar adipose reticular connective tissues

open handcuffs are like loose connective tissue as the bind and hold

Areolar Connective Tissues

• 4 functions:

- support/binds tissues

-holds body fluids

-defends against infection

-stores nutrients• Loose arrangment of fibers, thus the

name areola, which means “small open space”

• Soaks up excess fluid when body inflamed

• Most widely distributed connective tissue

• Binds body parts together• Present in all mucus membranes

Adipose reticular loose connective tissue

Adipose Connective Tissue

• Similar to areolar tissue in structure and function

• Nutrient storing capacity much greater

• Also known as fat tissues because adipocytes(fat cells) take up 90% of tissue’s mass

• Highly vascularized • High metabolic activity• Makes up 18% f human’s body weight• Functions:

- shock absorber, insulator, stores energy

Areolar reticular loose connective tissue