The human body: tissue types

The human body

• primary tissues:musclenervousepithelialconnective

• organs:composed of at least two primary tissues

• systems:organs located in different regions of the body that perform related functions

Primary Tissues

• muscle– skeletal– cardiac– smooth

• nervous tissue– neurons– glial cells

• epithelial tissue– membranes– glands

Primary Tissues

• connective tissue– fat (adipose)– cartilage– bone– blood

Epithelial Tissue

• membranes - flat sheets of cells that cover and line body surfaces

• Functions: lines, covers, produces glands

• Cells are connected together• Have a basement layer of connective tissue

• Avascular• Layers:

– simple = 1 layer, regulates transport– stratified = many layers, acts as barrier

• shapes of cells in upper layer vary - squamous, cuboidal, columnar

Epithelial Tissue

Epithelial Tissue

columnar epithelium lining tubules of epididymis(male reproductive system)

Epithelial Tissue

stratified epithelium lining trachea (respiratory system)

Connective Tissue

• Connective tissue is found everywhere in the body

• Functions: binds (connects) body parts; supports organs and systems, provides protection from mechanical damage

• Has both living (cells) and matrix (nonliving) components

• Matrix: lots of extracellular material between cells that is not alive – fluid– proteins

Types of Connective Tissue

• Types of connective:- Adipose - Areolar- Cartilage - Reticular- Osseous- Blood

Osseous Tissue

• Function: support the body and protect body cavities; produces blood

• Composed of bones cells in cavities called osteocytes, have a very hard matrix, and collagen fibers

Dense Connective Tissue

• Composed of collagen fibers• Types:

– Tendons: attach muscle to muscle– Ligaments: connects bones to bone

Areolar Tissue

• Web-like matrix• Functions:

– Cushions, protects– Soaks up water to act like glue that holds other tissues together

Connective Tissue

cartilage bone blood

Adipose Tissue

• Contains lipids• Cushions organs and stores nutrients

Reticular Tissue• Composed of delicate woven fibers• Forms stroma• Found in lymphatic organs

Blood

• Composed of fluid matrix called plasma

• Clotting fibers visible during clotting

• Cary nutrients, gases, and wastes through out the body

Connective Tissue

fat (adipose)

Muscle• Function: specialized to

contract or shorten to produce movement

• skeletal muscle“voluntary”striatedmultiple nuclei per cell

• cardiac musclefound only in heartspecialized striated muscle - not “voluntary”has intercalated discsuninuclei per cell

• smooth muscle

“involuntary”

not striated1 nucleus per cellattached to hollow organs like the stomach, intestines, esophagus

Muscle

intercalated

discs

Nervous Tissue

• neurons (nerve cells)• Function: irritability and conduction of impulses- Dendrites - receive information- Cell body - contains nucleus, metabolic center, integrates input

- Axon - conducts nerve impulses

• glial cellsprovide support - enhance electrical activity of neurons

Nervous Tissue