Lymphocytes and Immunity Flashcards
What is the normal range for Lymphocytes in dogs?
1,000-4,500 / microliter
What is the normal range for Lymphocytes in cats?
1,500-7,000 / microliter
What line of defense are Lymphocytes associated with?
3rd line (specific immunity)
True or False: Lymphocytes are not capable of phagocytosis
true
True or False: Lymphocytes are capable of recirculation
True
What is the life span of Lymphocytes?
weeks to months to years
What is Lymphocytosis?
increase in lymphocytes
What are the causes of Lymphocytosis?
- epinephrine release (splenic contractions)
- leukemia/neoplasia
- antigenic stimulation
- chronic inflammation
- later stages of resolving infections
- very young animals
What types of Leukemia/Neoplasia cause Lymphocytosis?
- lymphoma
- lymphosarcoma
What is Lymphopenia?
decrease in lymphocytes
What are causes of Lymphopenia?
- stress response
- immunosuppressive drug therapy
- immunodeficency syndromes
- acute viral diseases
- decreased production (bone marrow)
What immunosuppressive drug causes Lymphopenia?
tacrolimus
What immunodeficency syndromes cause Lymphopenia?
- FIV
- CIV
- combined immunodeficency syndrome
What acute viral diseases cause Lymphopenia?
- FeLV (acute stage)
- parvovirus
Nucleus (Lymphocyte)
- round, oval
- non segmented
- mononuclear
- dark purple
Cytoplasm (Lymphocyte)
- light blue
- has a high N:C ratio
What is the size of a Small Lymphocyte?
7-9 microns
Cytoplasm (Small Lymphocyte)
- little to no cytoplasm
- may see faint cytoplasm
What is the size of a Large Lymphocyte?
9-11 microns
Cytoplasm (Large Lymphocyte)
more abundant
What is a Reactive Lymphocyte?
- currently being stimulated
- AKA: immunocytes, stimulated lymphocytes, activated lymphocytes
What is the size of a Reactive Lymphocyte?
15-20 microns
Nucleus (Reactive Lymphocyte)
- large
- dense chromatin
- chromocenters
Cytolplasm (Reactive Lymphocyte)
- abundant
- intense blue
Where are Atyplical Lymphocytes seen?
- infections
- neoplasia
Nucleus (Atypical Lymphocytes)
indented or clefted
Cytoplasm (Atypical Lymphocytes)
- irregular borders
- dark blue cytoplasmic granules (due to asynchronous development of nucleus and cytoplasm)
What is Lymphocytopoiesis?
production of lymphocytes
Maturation process of a T Cell
PPSC Lymphoid Stem Cell Pre T-Cell T-Lymphoblast T-Prolymphocyte T-Lymphocyte (T-Cell)
Maturation process of a B-Cell
PPSC Lymphoid Stem Cell Pre B-Cell B-Lymphoblast B-Prolymphocyte B-Lymphocyte (B-Cell)
Where does the T-Cell mature?
thymus
Where is the T-Cell stored?
spleen (white pulp)
lymph nodes
What is the T-Cell’s role in immunity?
- cell mediated immunity (in tissue)
- use cytokines
- enter circulation and travel to site in tissue where antigen entered
What % of T-Cells are in circulation?
70%
Where does the B-Cell mature?
- :”Bursa Equivalent”
- GALT: gut associated lymphoid tissue
- bone marrow
Where is the B-Cell stored?
- spleen
- lymph nodes
- tonsils
- other lymphoid tissue
What is the B-Cell’s role in immunity?
- humoral immunity (plasma)
- use antibodies
- rarely seen in circulation
What % of B-Cells are in circulation?
30%
Where do Natural Killer Cells mature?
bone marrow
Where are Natural Killer Cells stored?
- spleen
- lymph nodes
- tonsils
- lymphoid tissue
What is the Natural Killer Cell’s role in immunity?
- non specific immunity
- 2nd line of defense
- effective against “traitor” cells
- must come in direct contact with cell
- require no activation
What are Memory Cells?
- B or T Cells
- clones of the original lymphocyte
Where are Memory Cells stored?
survive in lymphoid tisse waiting for 2nd exposure to antigen that stimulated their formation
What are the parts of the Lymphatic System?
- lymphatic ducts and vessels
- lymphatic tissue
What are the 3 compartments of the Lymphatic Tissue?
- bone marrow (where all cells originate)
- central lymphoid tissue (where lymphocytes mature)
- peripheral lymphoid tissues (where cells are stored until needed)
What are Peripheral Lymphoid Tissues?
- bone marrow
- GALT
- spleen
- lymph nodes
- tonsils
What is Plasma?
fluid portion of blood that carries nutrients, electrolytes, proteins, sugars, hormones etc
What is Lymph?
-comes from plasma
-primarily composed of water, electrolytes and sugars
doens’t contain large proteins like plasma
What are the primary functions of the Lymphatic System?
- removal of excess tissue fluid
- waste material transport
- filtration of lymph
- protein transports
What things get filtered out of the Lymph?
- microorganisms
- cellular debris
- metabolic waste products
- any foreign matter or waste material
What proteins does the Lymphatic System transport?
-enzymes
-hormones
-other proteins
(carried from the tissue of origin into blood)
What are the Tissues and Organs of the Lymphatic System?
- lymph nodes
- spleen
- thymus
- tonsils
- GALT
Where is the Spleen located in the body?
- left side of abdomen
- near stomach
What are the 2 types of function of the Spleen?
- Hematologic
- Lymphatic
What are the Hematologic functions of the Spleen?
-blood storage
-removal of foreign material and debris
(occurs in the red pulp)
What are the Lymphatic functions of the Spleen?
-activation and cloning of lymphocytes
occurs in the white pulp
True or False: The spleen is not essential for life
True
What is the #1 reason for a Splenectomy?
rupture/trauma