### cell | leukocyte:

Lymphocyte
* All lymphocytes develop in the bone marrow from immature cells called stem cells
  - originate in the bone marrow as immature cells called stem cells
* Make immune responses.
* Most lymphocytes are part of bodies
  - programmed to die , and are replaced by newly matured cells
  - very sensitive and easily damaged by x-rays
  - enter and leave the spleen by way of the bloodstream
* Some lymphocytes act as tumor-killing cells
  - are capable of reacting against self, resulting in an autoimmune reaction
  - have a lifespan of months or years
  - leave and reenter the circulation, surviving for many years
* also cause tissue-rejection during organ transplants.
* are a part of the immune system and can be affected by many diseases.
* are a type of immune cell that is involved in tumor and antimicrobial surveillance
  - leukocyte responsible for the immune response
* are a type of white blood cell in the body which are crucial for fighting infections
* are a very heterogeneous population of cells in size shape and function
  - important part of the bird s immune system
  - white blood cell with important functions in the immune system
  - able to respond to a huge number of antigens
  - also present in the submucosa
  - an important part of the immune system
  - another important somatic cell type
* are cells important to fighting infection
  - produced by the lymph system and found in human blood
* are cells that attack the bacteria directly
  - have a dense nucleus and a small amount of cytoplasm
  - recognize antigens in a specific manner
  - colorless cells of the blood and made in lymph glands
  - complex cells that direct the body's immune system
  - critical cells in the immune system
  - formed in lymphatic tissue throughout the body
  - immune system cells that have large round nuclei
  - important component cells of the immune system
  - leukocytes
  - mobile, migratory cells
  - more specific in the invaders they target
  - much more common in the lymphatic system
  - of two major kinds, T cells and B cells
  - one kind of white blood cell in the blood system
* are part of the immune system which guards the body against germs or alien substances
  - normal defence system of the body
  - poorly motile, and usually appear at the site of inflammation later in the process
* are present among hyperplastic enterocytes
  - the decidua surrounding the vessel
  - and are produced in the lymphatic tissues
  - in the lamina propria
* are produced in bone marrow
  - lymph nodes throughout the body
  - regular
* are responsible for immune memory
  - round white blood cells a bit bigger than a red blood cell
* are small white blood cells circulating throughout the lymphatic system
  - that travel through the lymph system
  - with round nuclear contour and clumped chromatin
* are the body's major disease fighters
  - cells that attack bacteria in the blood
  - first cells that arrive at the site of inflammation
  - key cells controlling the immune system
  - main cell type of the immune system
* are the primary effectors of adaptive immune responses
  - officers of the immune defense
  - smallest white blood cells and are the backbone of the immune system
  - very important to the body's immune functions
  - virtually absent from the PALS and there are no lymphoid follicles
  - white blood cells that are part of the immune system
* are, in some respects, the most important cells in the immune system.
* arriving from bone marrow populate the outer margins of the cortex.
* attack foreign cells directly or secrete an enzyme that immobilizes foreign substances.
* become specialized during an infection and produce the body's immune response.
* belong to the white blood cell family.
* can also accumulate in the connective and epithelial tissues throughout the body
  - appear reactive
  - destroy certain cancer cells
  - live for weeks, months or years
* circulate in the blood and lymph systems, and make their home in the lymphoid organs
  - make up twenty per cent of the white cells
* circulating in the blood are normally spherical with randomly displayed microvilli.
* come from bone marrow and from lymph glands.
* comprise a critical component of host defenses against cryptococcosis.
* contain high concentrations of deoxycytidine kinase.
* continually pass back and forth between lymph tissue, lymph fluid and blood.
* control antigen-specific immune responses and their outcomes
  - the body's ability to recognize and fight infections and cancers
* disappear and are replaced by fat tissue from the partitions between the lobules.
* enter here via the afferent lymphatics
  - the lingual tonsil via afferent lymphatics
* express receptors with varying affinity for the antigen in question.
  - infections by viruses and bacteria
* function in antibody and antigen production and cellular and humoral immune reactions
  - immune process See the formation of immune cells
* have a dense nucleus with little cytoplasm
  - markedly abnormal appearance when visualized by scanning electron microscopy
  - unique structure which allows then to respond to antigens
* help defend against infections
  - govern immunity and are responsible for antibody production
  - with our immune response
  - chromosomes
  - corpi
  - cytoskeletons
  - vacuoles
* infiltrate the intralobular stroma, which becomes dense.
* integrate multiple input signals to regulate the extent of their proliferative response.
* invade the limiting plate and surround and destroy hepatocytes.
* make a molecule called granzyme B which enters a perceived enemy cell to kill it
  - up one of the classes of white blood cells
* manufacture antibodies and are vital for immunity.
* often invade the epithelium or form solitary lymphoid nodules in the lamina propria.
* originate from the bone marrow.
* produce specific antibodies when exposed to antigens.
* protect against the growth of tumors.
* reach every cell of the body, carried in lymphatic channels to every organ and tissue.
* rearrange, edit, and revise their antigen receptors to be useful yet safe.
* recognise pathogens with antigen receptors.
* recognize and help destroy in body fluids and cells.
* start in the bone marrow.
* stimulated by antigen undergo a process of mutagenesis and selection.
* support the immune system.
* surround a vessel near the bottom.
* travel in the bloodstream, as well
  - locally in a lamina propria of a mucosa
* undergo a phase of antigen-independent development in the thymus or bone marrow.
* vary in life span with some living only a few days while others ciculate for many years.
* wander through the lymph spaces in the body, resting and proliferating in lymph nodes.
+ White blood cell, Types of white blood cells, Lymphocytes: Cell biology :: Immunology :: Blood cells
  * Lymphocytes are round white blood cells a bit bigger than a red blood cell. Their center is round and they have little cytoplasm. Part of the lymphatic system, these target specific germs or poisons using their antibodies.