THE LYMPHOID SYSTEM IMMUNITY Flashcards
ability of an individual to resist infections by means of normally present body functions
natural immunity
The most important process of internal defense mechanism is the process of
phagocytosis
how many percents do lymphocytes constitute in the circulating wbc’s ?
20-40%
The second dominant type of WBC after Neutrophils
lymphocytes
Cytoplasm is SPARSE, containing few organelles and NO SPECIFIC GRANULES, and consists of a narrow ring surrounding the nucleus.
lymphocytes
These cells are unique, because they arise from a __ and then are further differentiated in the primary lymphoid organs.
hematopoietic stem cell
__organs is where the maturation of B and T cells occurs
Primary lymphoid
mother of all cells , origin of all cells in the body
Hematopoietic stem cells
hematopoietic stem cells can be differentiated into two, what are they?
common lymphoid precursor and common myeloid precursor
Lymphocyte circulation is complex and is regulated by different cell surface adhesion molecules and by chemical messengers called ___
cytokines
where does the t cell differentiation occurs?
thymus
b cell differentiattion occurs in
bone marrow
- Once the cell matured, they travel to the ___ for proliferation and differentiation
secondary lymphoid organs
what are the 3 major population of lymphocytes
t cell, b cell, and nk cell
give the percentage of each major population of the lymphocytes
- 61-80% - T cells,
- 20 % - B cells,
- 10-15% - NK cells
whata re the 2 primary lymphoid organs?
bone marrow and thymus
whata re the example of secondary lymphoid organs
- Spleen,
- Lymph nodes
- Mucosal-Associated Lymphoid Tissue (MALT)
- Appendix
- Tonsils
- Peyer’s Patches
- Cutaneous-Associated Lymphoid Tissue (CALT
which precursor do - T cells, B cells, and NK cells arise from
common precursor known as the CLP or common lymphoid precursor cell
o ___ fills the core of all flat long bones and is the main source of hematopoietic stem cells, which develop into different cell types.
Bone marrow
it is the source of our hematopoietic stem cell
bone marrow
is an organ which is small, flat, bilobed organ found in the thorax, or chest cavity, right below the thyroid gland and overlying the heart.
thymus
T cells developed their identifying characteristics in
Thymus
weight of thymus at birth, puberty, and old age
- 30 g (at birth) →35 g (puberty) →atrophy
- Each lobe of the thymus is divided into ___ filled with epithelial cells that play a central role in this differentiation process.
lobules
- Surface antigens are also called __
surface markers
surface antigens/surface markers the lymphocytes travel from the cortex to the medulla over a period of __
-2 to 3 weeks.
CCortex and medulla is where the T cells stays, but once they matured, it will be released in
medulla
___ is the main contact or main access to antigens
Secondary lymphoid organs
also called as antigen trapping site
secondary lymphoid organs
Largest secondary lymphoid organ
spleen
o Characterized as a large discriminating filter because it removes OLD AND DAMAGE cells and foreign antigens from the blood
spleen
length and weight of spleen in adult
12 cm and 150g in adult
Splenic tissue can be divided into two main types:
o Red Pulp
o White Pulp:
makes up more than one-half of the total volume of the spleen,
red pulp
a splenic tissue and its function is to destroy old red blood cells.
red pulp
comprises approximately 20 percent of the total weight of the spleen and contains the lymphoid tissue, which is arranged around arterioles in a periarteriolar lymphoid sheath (PALS).
white pulp
how many percent to white pulp constitute in the spleen
20%
o PALS is a sheath that contains mostly___
T cells
Attached to the periarteriolar lymphoid sheath are ___
primary follicles
Primary follicles contains the ___ that not yet stimulated with the antigen because its purpose is to produce the antibody
B cells
o Surrounding the PALS is a marginal zone containing ___ that trap antigen.
dendritic cells
is the most potent phagocytic cell and is considered the best antigen presenting cell (APC)
dendritic cells
- PALS –XXXX
- Primary follicles – XXX
- Marginal zone – XXXX
- PALS – t cells
- Primary follicles – b cells (not yet stimulated)
- Marginal zone – dendritic cell
Located along lymphatic ducts and serve as central collecting points for lymph fluid from adjacent tissues.
lymph nodes
size of the lymph nodes
1-25mm in diameter
: it allows ideal environment for contact between the lymphocytes and foreign antigens from the tissue to take place
lymph nodes
- Lymph nodes can be enlarged when there is an ___
infection
The lymph fluid flows slowly through spaces called ___, which are lined with macrophages, creating an ideal location for phagocytosis to take place.
sinuses
sinuses, in where the lymph flid flows are lines with what wbc?
macrophages
Spleen protects us but lymph nodes help to SET UP ENVIRONMENT
true or false
true
what are the 3 parts of the ymp nodes
cortex, paracortex, medulla
Outer most region of lymph nodes
cortex
cortex has the germinal centers, which has the unstimulated ___
b cells
part of lymp nodes where we can find the t cells
paracortex
- A place where the t cells and b cells are released once matured
medulla
Accumulation of the lymphocytes and other cells will cause the lymph nodes to become enlarged, this condition is called
lymphadenopathy
Can be found in the gastrointestinal, respiratory and urogenital tracts
MUCOSAL-ASSOCIATED LYMPHOID TISSUE (MALT
an exampleof mucosal-assciated lymphoid tissue is the
appendix which is located at the junction of the small and large intestines.
example of mucosal-associated lymphoid tissue found in the mucous membrane lining of the oral and pharyngeal cavities.
tonsils
it responds to the pathogen entering the respiratory and alimentary tracts
tonsils
3rd example of MALT
peyer’s patches
are located at the lower ileum of the intestinal tract
peyer’s patches
considered as the lymphoid tissue in the intestine
peyer’s patches
a secondary lymphoid organ that is - Within our epidermis
CUTANEOUS-ASSOCIATED LYMPHOID TISSUE
- Considered as the largest organ in the body and epidermis
CUTANEOUS-ASSOCIATED LYMPHOID TISSUE
- Epidermis contains a number of __.
intraepidermal lymphocytes
- Intraepidermal lymphocytes mechanism
o T cells are uniquely positioned to combat any antigens that enter through the skin
aside from the t cells, what are the other wbc acting as intradermal lymphocyte
monocytes, macrophages, and dendritic cells
- Within each of these secondary organs, T and B cells are segregated and perform specialized functions
where do T cells function for
cell-mediated immunity
B cells can differentiate into
memory or plasma cells
are small polypeptides that regulate the functions of lymphocytes and other cells involved in the immune response
cytokines
- __ has high affinity to the particular antigen, which is the surface markers on lymphocytes
Monoclonal antibodies
In terms if B cells – surface markers
CD19, CD21, and CD23
In terms if T cells – surface markers
CD2, CD3, CD4, and CD8
In terms if NK cells – surface markers
CD16, CD56, and CD94
o Precursor of lymphocytes is __within the lobules of the thymus: the outer cortex and inner medulla
thymocytes
The earliest marker is the ___
PRO-B Cell
- Considered as the earliest B-cell precursor that could recognize the presence of a surface molecule/marker
Pro B cell
surface marker associated in Pro B cell
CD45R
the end result of pro b cell is a ___ programmed to produce a unique antibody molecule, which consists of two identical light chains and two identical heavy chains
B lymphocyte
is a TYROSINE specific phosphate that is involved in signaling during the B cell activation
cd45r
The differentiation of Pro B cell to Pre B cell occurs upon successful rearrangement of ___
heavy chain genes
Heavy Chains are coded on chromosome __
14
Light Chains are coded on chromosome __
2 and 22
The pro-B cell has DISTINCTIVE MARKERS that include surface antigens ___.
CD19, CD45R, CD43, CD24, and c-Kit
- Not all of these are scattered. There is a cluster of differentiation where it will only stay on the surface of developmental stage of a certain cell.
- The only that would stay are the ___
CD19, CD24 and CD45r
