FACTOID # 10: The total number of state executions in 2005 was 60: 19 in Texas and 41 elsewhere. The racial split was 19 Black and 41 White.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > B lymphocyte

B cells are lymphocytes that play a large role in the humoral immune response (as opposed to the cell-mediated immune response). The abbreviation "B" stands for the bursa of Fabricius which is an organ unique to birds, where B cells mature. It does not stand for bone marrow, where B cells are produced in all other vertebrates.


The human body makes hundreds of different types of B cells, and each type has a unique receptor protein on its membrane that will bind to one particular antigen; at any one time in the human body millions of B cells are circulating in the blood and lymph, but are not producing antibodies. There are two types of B cells:

  • Plasma B cells secrete antibodies which effect the destruction of antigens by binding to them and making them easier targets for phagocytes.
  • Memory B cells are formed specific to the antigen(s) encountered during the primary immune response; able to live for a long time, these cells can respond quickly upon second exposure to the antigen for which they are specific.

Humoral immunity (the creation of antibodies that circulate in blood plasma and lymph) involves B cell activation. Cell activation can be gauged using the ELISPOT technique, which can determine the percentage of B cells that secrete any particular antibody.


B cells are characterised immunohistochemically by the presence of CD20 on the cell membrane.


Susumu Tonegawa won the 1987 Nobel Prize in Physiology or Medicine for demonstrating how B cells create the enormous diversity of antibodies from only a few genes.



Immune system
Humoral immune system - Cellular immune system - Lymphatic system
White blood cells - B cells - Antibodies - Antigen (MHC)
Lymphocytes: T cells (Cytotoxic & Helper) - B cells (Plasma cells & Memory B cells)





  Results from FactBites:
 
B cell - Wikipedia, the free encyclopedia (660 words)
B cells are lymphocytes that play a large role in the humoral immune response (as opposed to the cell-mediated immune response).
B cells are characterised immunohistochemically in humans by the presence of CD20 on the cell membrane.
B cells are continuously produced in the bone marrow, but only a small portion of newly made B cells survive to participate a part in the long-lived peripheral B cell pool.
Lymphocyte - Wikipedia, the free encyclopedia (539 words)
T cells are chiefly responsible for cell-mediated immunity whereas B cells are primarily responsible for humoral immunity (relating to antibodies).
T cells are named such because these lymphocytes mature in the thymus; B cells, named for the bursa of Fabricius in which they mature in bird species, are thought to mature in the bone marrow in humans.
A lymphocyte count is part of a peripheral complete blood cell count and is expressed as percentage of lymphocytes to total white blood cells counted.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m