Types of Movement

The cells of the human body show three main kinds of movement: amoeboid, ciliary and muscular movement.

Amoeboid movement

Some specialised cells move by putting out temporary projections of themselves rather than by contracting muscle. This is called amoeboid movement, after the way Amoeba itself creeps along. In the human body, cells such as macrophages and the leucocytes (white blood cells) of the blood move in this way.

• It is produced by pseudopodia ("false feet"), which form as the protoplasm inside the cell streams in a particular direction and pushes the cell forward.
• Cytoskeletal elements, particularly the fine filaments called microfilaments, are also involved in bringing about this movement.

Ciliary movement

Most of the body's internal tubular organs are lined by a ciliated epithelium. Ciliary movement is the coordinated beating of these cilia, and it does real physiological work in more than one place:

• In the trachea, the coordinated beating of cilia helps remove dust particles and other foreign substances that are inhaled along with the air we breathe.
• In the female reproductive tract, ciliary movement helps carry the ovum along the tract.

Muscular movement …