Organs of Immune System

 

All leukocytes are produced and mature in the bone marrow, except T lymphocytes, that mature in the thymus*. Mature leukocytes circulate constantly between the lymph nodes* and the spleen through blood vessels and lymphatic vessels.

*Thymus: organs located in the chest, at the basic of the strenum. 

*lymph nodes: small organs of the lymphatic network in which immune responses take place.

*Spleen: organ located in the upper left part of the abdomen (Dakroub, 2011).

Organs of Immune system, 
Image from(Immunator Honey, 2013)

The Immune System
Video taken from (Eexcelfood@cox.net Nutritional Immunolog, 2011)

References

Immunator Honey. (2013, May). Organs of the Immune system. Retrieved from http://immunatorhoney.com/index2.php?data=sisover

Dakroub, R. N. (2011). Life and Earth Sciences. Lebanon, Sin El Fil: center for educational resarch and Development, Educational Company.

Eexcelfood@cox.net Nutritional Immunolog. (2011, March 18). The Immune System[Video file]. Retrieved from https://www.youtube.com/watch?v=83eM0FD6Ox0.

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

Introduction about the Immune System

All living organisms are surrounded by millions of bacteria, viruses and other microbes (germs) that may enter our bodies and cause harm. Animals with backbones, called vertebrates, have these types of general protective mechanisms, which have an advanced protective system called the immune system. (www.patient.co.uk)The immune system is a complex network of organs containing cells that recognize foreign substances which are called antigens in the body and kill them. This system protects vertebrates against pathogens, or infectious agents, such as viruses, bacteria, fungi, and other parasites. (Aberystwyth University). Nonliving substances such as toxins chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys them (U.S. National Library of Medicine, 2014).

This video is taken from Segment from the program The Immunological System: Recognition, Attack, and Memory. retrieved on November 28, 2014 from http://www.greatpacificmedia.com/

Where is the immune system found?

Immune system Structure
Retrieved from "Immune system structures: MedlinePlus Medical Encyclopedia Image," 2013)

References 

Aberystwyth University. (n.d.). Retrieved November 5, 2014, from An Introduction to the Immune System: http://www.aber.ac.uk/~dcswww/ISYS/immune_system.html

U.S. National Library of Medicine. (2014, 11 5). Retrieved November 8, 2014, from http://www.nlm.nih.gov/medlineplus/ency/article/000821.htm


www.patient.co.uk. (n.d.). Retrieved November 5, 2014, from http://www.patient.co.uk/health/the-immune-system

Image: Immune system structures: MedlinePlus Medical Encyclopedia Image. (2013, September 15). Retrieved November 20, 2014, from http://www.nlm.nih.gov/medlineplus/ency/imagepages/8932.htm

Self And Non-Self

Every human being has the capability to recognize and accept what belongs to his own body, the 'self'', an to recognize and reject what foreign, the 'non self''.(Dakroub, 2011)

Marker of 'Self'': the HLA System 

the 'self'' is determined by a set of molecules , specific to each individual , that are expressed on the membrane of nucleated cells*. The most important ones are the proteins of the Human Leukocyte Antigen(HLA) system. They are genetically determined and called '' markers'' because they represent a''biological identity card' unique to each individual.
HLA molecules are identical on all cells of single and different from one person to another(Dakroub, 2011).

* nucleated cell: cell that has nucleus.

Retrieved November 27, 2014, from http://img.thebody.com/nih/2006/cancer2.jpg

'Non-Self''Non -Self encompasses all that is recognized by the body as being different from 'self'. It includes allergens (non-harmful substances), pathogens( microbes and their products), cells and tissues of the other individuals, but also own cells and tissues, if they are modified by an infection or a cancerous transformations*.

* Cancerous transformation: uncontrolled and abnormal divisions of a cell.The immune system is able to distinguish between ''self'' molecules, that it will tolerate, and 'non-self' molecules that is will reject. All these rejected molecules are called antigens*.

* Antigens: substance that is specially recognized by the immune system as foreign body.

Markers of the Non- Self 
.The National Cancer Institution.Retrieved November 27, 2014, from http://img.thebody.com/nih/2006/cancer3.jpg
Refercences
Dakroub, R. N. (2011). Life and Earth Sciences. Lebanon, Sin El Fil: center for educational resarch and Development, Educational Company.