cytoskeleton of the cell

BY

Nouf al-yami

cytoskeleton of the cell

The cytoskeleton forms the skeleton of each cell and is responsible for its specific shape.

It consists of several classes of structural element which are:

the Microtubules

the Microfilaments.

the Intermediate filaments.

the Microtubules

in all kinds of cells.

cylindrical filamentous structures 25 nm.

made of protein tubulin.

appear as tiny circles in cross section.

anchored in region near the centeriole of the cell.

long and are elastic to bend without breaking.

Figure: Falgilam.

function of Microtubules

Skeleton of the cell.

Transport.

Move the cilia through the action of Axonemal Dynein.

Cell division(cytotoxic drugs).

the microtubules

the Microfilaments

There are tow type(7nm) of microfilaments:

1- Actin filaments (thin filament, muscle cells).

2- Myosin filaments (thick filaments, muscle cells) .

function of Microfilaments

Muscle contraction.

Amoeboid movemement (white blood cells).

Blood clot( blood platelets).

The separation of the dividing cells.

Microvilli (terminal webs).

The Microfilaments

the Intermediate filaments

There are five types (10nm):

keratin filaments (epithelial cells).

Desmin filaments (smooth muscle,skelent,cardic).

Vimentin filaments (connective tissue fibroblast cells).

Neuro- filaments (nerve cells).

Glial filaments (neuroglia cells).

the Intermediate filaments

Microvilli

They are finger like projection on the surface of certain cells of the body, for example; cells of the intestine.

They are formed of microfilaments covered with the cell membrane.

They are increase the surface area of the cell.

Microvill