Tissue

Groups of cells similar in structure and function

FFF

Nervous tissue: Internal communication • Brain, spinal cord, and nerves

Muscle tissue: Contracts to cause movement • Muscles attached to

• Muscles of heart ( ) • Muscles of walls of hollow organs (smooth)

Epithelial tissue: Forms boundaries between different environments, protects, secretes, absorbs, filters • Skin surface ( ) • Lining of GI tract organs and other hollow organs

Connective tissue:

• Bones • Tendons • Fat and other soft padding tissue

*Epithelial Tissue (Epithelium)

Two main types (by location): 1.

On external and internal surfaces 2.

Secretory tissue in glands

Characteristics

Cells have polarity—upper and lower surfaces Are composed of closely packed cells Continuous sheets held together by tight

junctions and Supported by a connective tissue reticular

lamina (under the basal lamina) Avascular but High rate of regeneration

Classification

Ask two questions: 1. ?

1 = simple epithelium / pseudostratified >1 = stratified epithelium

2. ? Squamous Cuboidal Columnar

(If stratified, name according to upper layer of cells)

Simple

Stratified

Apical surface

Apical surface

Basal surface

Basal surface

Squamous

Cuboidal

Columnar

Simple Squamous Substances easily pass through Lines blood vessels and lymphatic vessels Lines (alveoli) Function:

Simple Cuboidal Single layer of Lines kidney tubules Covers ovaries Lines ducts of some glands Function:

Simple Columnar Single layer of May have cilia May contain microvilli Often have Lines the

Function:

Pseudostratified Columnar Single layer of cells that

Usually contain cillia and goblet cells Lines the

Stratified Squamous Epithelium Many cell layers Top cells

shaped Can accumulate Makes up the outer skin layer (Epidermis) Lines oral cavity (think gums), vagina, and

anal canal Function:

Transitional Epithelium Many cell layers Changes thickness Lines the urinary bladder, ureters and part of

urethra

*Connective tissues 3 Types:

Fibroblasts: Large, star shaped Fixed cells

Macrophages Wandering cell

Mast cells Fixed Release heparin – Release histamine – promotes reactions of

Major Fiber Types Fiber

Thick with great strength Composed of Abundant in dense connective Found in tendons and ligaments

Fiber Types Fiber

Composed of Fibers are branched and flexible Found in

Fiber Types fibers

Very thin collagenous fibers Highly branched Forms supportive network

Loose Fibrous Connective Contains many Fluid to gel like matrix Collagenous and elastic fibers Binds skin to Found beneath most epithelia Found

Adipose Connective Has specialized cells called

Cushions, insulates, and stores fat Found under the skin Found

Connective Compose of Provides Forms the framework for liver, spleen, and

other lymphatic organs

Dense fibrous connective Packed with Has only a few Poor blood supply Binds body parts together Forms tendons and ligaments Found in

Elastic Connective Abundant with elastic fibers Few Contains fibroblasts Found as attachment between

Found in the walls of large arteries, airways and the heart

Bone Connective Solid matrix Cells called osteocytes Cells found in (chambers) Supports and protects Provides attachment for Produces blood cells

Blood Connective Fluid matrix called Red blood cells, white blood cells and

Function: Defends against infection Aids in Contained within blood vessels

*Cartilage Rigid Matrix (cells) in lacunae

(chambers) Poor blood supply

3 Types:

Hyaline Cartilage Connective Most type Found on the Forms part of the rib cage Located on the tip of the nose & in resp.

passages Forms the

Elastic Cartilage Connective Forms external ear Found within the

Fibrocartilage Connective Very tough Acts as a Forms Pads within the knee and pelvic girdle

*Muscle Tissue Skeletal

Attached to bones

Smooth muscle Not Found in the walls of internal organs & blood

vessels Located in the

Cardiac muscle Contains intercalated discs Found in the walls of the heart

* Nerve Tissue

• Cells are called

• Function in

*Membranes Serous

Lines body cavities that Contains serous fluid Composed of epithelial and connective tissue Inner lining of the thoracic and abdominal cavities

membranes Mucous

Lines tubes and organs Secretes Composed of epithelial and connective tissue Lines oral and nasal passageways, digestive tract,

respiratory tract, urinary & Reproductive tract

membranes Cutaneous

Covers Composed of epithelial and connective tissue Skin!

membranes Synovial

May contain Secretes Composed of connective tissue Inner lining of joints