Cells, Molecules and Organs of the immune System

The immune system is responsible for the defense against exterior aggressions. It includes specialized cells, the molecules they secrete and the organs that contain them.

 1- Cells involved in Immunity 

Cells involved in immunity are White blood cells, also called leukocytes Dakroub(2011).

Different types of Leukocytes
(RnCeus.com, 2013)

Aspect	Particularities
Monocyte	-          Horseshoe-shaped nucleus -          cross capillary walls and become macrophages in tissues -          Have a phagocytic ability
Granulocytes	-          Also called polymorphonuclear cells because they have multilobed nucleus -          Cross capillary walls -          Have a phagocytic ability
Lymphocytes	B lymphocytes :  Round nucleus                                Secrete antibodies
	T Lymphocytes:  Round nucleus                               Killer cells

2- Antibodies
Antibodies are the Y- shaped proteins produced by the B lymphocytes. They bind antigens in an interlocking manner resembling puzzle elements. antibodies can recognize cellular and soluble antigens Dakroub, R. N. (2011).

Antigen binding by antibodies
+ binding: - no binding
Picture taken by Ghinwa Massri from Life and Earth Science, Grade eight.

References:

RnCeus.com. (2013, February). White blood cells. Retrieved from http://www.rnceus.com/cbc/cbcwbc.html