Locomotion of cells

1. Locomotion of cells
Prepared by Fatima sundus

2. TYPES OF CELLULAR MOVEMENTS
 AMEBOID MOVEMENT
 CILIARY MOVEMENT
AMEBOID MOVEMENT
• Ameboid movement is movement of an entire cell in relation to its surroundings.
e.g movement of white blood cells
• It receives its name from the fact that amebae move in this manner
• Involves pseudopodium and ATP

6. MECHANISM OF AMEBOID LOCOMOTION.
Two effects are essential for forward movement of the cell.
▪ The first effect is attachment of the pseudopodium to surrounding tissues so that it
becomes fixed in its leading position, while the remainder of the cell body is pulled forward
toward the point of attachment. This attachment is effected by receptor proteins that line the
insides of exocytotic vesicles.
▪ The second essential effect for locomotion is to provide the energy required to pull the cell
body in the direction of the pseudopodium.

7. Types of cells that exhibit Ameboid movement
 White blood cells
 Fibroblasts
 Embryonic cells
 Germinal cells of the skin

8. CONTROL OF AMEBOID LOCOMOTION-CHEMOTAXIS
 The most important initiator of ameboid locomotion is the process called chemotaxis,
which results from the appearance of certain chemical substances in the tissues.
 Any chemical substance that causes chemotaxis to occur is called a chemotactic
substance.
 Most cells that exhibit ameboid locomotion move toward the source of a chemotactic
substance—that is, from an area of lower concentration toward an area of higher
concentration—which is called positive chemotaxis.
 Some cells move away from the source, which is called negative chemotaxis.

10. Cilia and Ciliary movements
• Whiplike movement of cilia on the surfaces of cells.
• A sharp pointed hair projecting 2- 4 micrometers from the surface of the cell.
CELLS EXHIBITING CILIARY MOVEMENT
1- Respiratory airways
2- Uterine tubes (fallopian tubes) of the female reproductive tract.

14. Structure of a cilium
• Covered by an outcropping of cell membrane
• Supported by 11 microtubules, 9 double tubules at the periphery and 2 single tubules down the
center.
• Each cilium is an outgrowth of a structure that lies immediately beneath the cell membrane, called
basal body of the cilium

16. • All the tubules are linked to one another by a complex of protein cross linkages, together
called the axoneme.
• Multiple protein arms composed of the protein dynein (having ATPase activity) project
outward from each double tubule
• ATP and appropriate magnesium and calcium concentration required.

19. .FLAGELLUM
▪ Longer in size
▪ Quasi-sinosidal movement
CILIUM
▪ Shorter in size
▪ Whip like movement