TISSUES There are different types of tissues classified according to their function. Epithelial...

TISSUES• There are different types of tissues

classified according to their function.• Epithelial forms the linings of

passageways and glands• Connective tissue forms the framework

of the body• Muscle tissue is for movement and

forms organs• Nervous tissue is to transmit impulses.

Epithelial Tissue

• Epithelial tissue is classified according to its shape and whether or not it is layered.

• Simple tissue is in one single layer.

• Stratified is in many layers.

SIMPLE SQUAMOUS

These cells form a single layer with pointed edges that overlap for protection.

They form the linings of cavities.

STRATIFIED SQUAMOUS

These cells form the outer layer of the skin.

SIMPLE CUBOIDAL

These cells are square in shape.

Each cell is almost a perfect cube.

• These cells form the lining of glands and are found in the kidneys.

STRATIFIED CUBOIDAL EPITHELIUM

Stratified cuboIdal cells are more than one layer of cells

SIMPLE COLUMNAR

The cells are commonly found in the intestines.

These cells use active transport to move digested materials into the blood.

PSEUDOSTRATIFIED

Since their nuclei are at different heights, these cells give the appearance that they are layered but in reality it is a single layer.

PSEUDOSTRATIFIED CILIATED COLUMNAR

These cells line the trachea and upper respiratory tract

TRANSITIONAL EPITHELIUM

This tissue consists of several layers of epithelial cells.

The cells are able to expand and contract.

They are found in the urinary tract especially the bladder.

Connective Tissue• Connective tissue has a

connecting function.• It supports and binds other

tissues.• It typically has cells scattered

throughout an extracellular matrix which is non-living.

CONNECTIVE TISSUE

Loose Connective Tissue

• This is the most common type of connective tissue in vertebrates.

• It holds organs in place and attaches epithelial tissue to underlying tissue.

• It is named according to the type of weave and fibers that it has.

• It contains three main fibers.

ELASTIC FIBER

These fibers are made of elastin and are stretchable

Collagen Fibers

• These fibers consist of fibrils that are bundles of collagen molecules.

Reticular Fibers

• These fibers join connective tissue to other connective tissue

Loose Connective Tissue

Fibrous Connective Tissue

• This tissue consists of large amount of closely packed collagenous fibers.

• It is found in tendons and ligaments

ADIPOSE

This is a loose connective tissue that stores fat in large vacuoles.

CartilageThis tissue is composed of closely packed collagenous fibers in a rubbery gelatinous substance called chondrin.

It is found in the nose, trachea and ears as well as the end of long bones.

Osseous TissueBone is a type of mineralized connective tissue that contains collagen and calcium phosphate, a mineral crystal. Calcium phosphate gives bone its firmness.

BLOODBlood is considered to be a type of connective tissue. Even though it has a different function in comparison to other connective tissues it does have an extracellular matrix.

SKELETAL MUSCLE

Each cell is cylindrical, unbranched and contains many nuclei.

The characteristic striations seen are a result of the orderly arrangement of actin and myosin filaments within the muscle cell.

SKELETAL MUSCLE

SMOOTH MUSCLE

Smooth muscle features long, narrow "spindle" shaped cells with a single central, somewhat elongated, nucleus. These cells are arranged parallel to one another and do not show any striations microscopically.

This type of muscle is called "involuntary" because it acts to contract and relax without conscious thought .

SMOOTH MUSCLE

CARDIAC MUSCLE

Cardiac muscle shows some features of skeletal muscle and smooth muscle.

Cardiac muscle is the muscle that makes up the wall of the heart.

Cardiac muscle is similar to skeletal muscle in that it is striated and multinucleated, and similar to smooth muscle in that the nuclei are centrally located.

NEURON The neuron is the functional unit of the nervous system.

All neurons have three parts.

Dendrites receive information from another cell and transmit the message to the cell body.

The cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells.

The axon conducts messages away from the cell body.