1What is the % of lymphocytes of circulating white blood cells?
20-40%
2What are the 2 primary lymphoid organs?
bone marrow and the thymus
3Where are T cells made?
thymus
4Where does B cell maturation take place?
bone marrow
5What produces antibodies?
B lymphocytes
6How does T and B lymphocytes circulate?
from the bloodstream to the secondary lymphoid organs and back (to increase contact with foreign antigens)
7What are the 3 kinds of lymphocytes?
T and B lymphocytes and NK cells
8What are the secondary lymphocytes?
spleen, lymph nodes, and mucosal associated lymphoid tissue (MALT)
9What does the spleen filter? How does it differ from lymphatic system
spleen filters antigens in the blood whereas the lymphatic system filters fluid from the tissue
10What cells do the bone marrow cells make?
B cells and NK cells
11What does antigen-independent mean?
has no contact with antigen yet (naïve) and die unless activated by antigen in secondary lymphoid organs
12Where do immune cells develop?
primary lymphoid organs
13Where do T cells develop and mature?
T cells develop initially in the bone marrow but migrate to thymus to achieve full maturity
14What are the purpose of chemokines?
drives t cell maturation within thymus
15What interaction allows t cell maturation to take place?
interaction of immature thymocytes with the stromal cells and IL-7 allows T cell maturation (in thymus)
16Where do t cells develop identifying characteristics?
thymus (max size in puberty)
18CD3+ and CD4+
mature helper T cell
19CD3+ and CD8+
mature cytotoxic t cell
20Where are mature t lymphocytes released?
the medulla
21What happens after differentiation occurs?
mature T and B lymphocytes are released from the bone marrow and thymus
22Where do mature lymphocytes migrate to?
secondary lymphoid organs and become part of recirculating tool
23What is the main goal of secondary lymphoid organs?
to allow first contact with antigen
24What is the purpose of first contact in secondary lymphoid organs?
to increase the prob of an immune response
25What are the secondary lymphoid organs?
spleen
lymph nodes
Mucosal-associated lymphoid tissue (MALT)
cutaneous-associated lymphoid tissue (CALT)
26What regulates lymphocyte circulation between secondary organs?
surface adhesion
27What does lymphopoiesis depend on?
antigen stimulation
28What does antigen-dependent maturation give rise to?
memory cells
29How are lymphocytes segregated?
according to their particular function
30What is the lymph cell called after 1st exposure to antigen?
antigen Dependent
31What is the filtering mechanism for antigens in blood stream?
spleen
32What is the purpose of red pulp?
to destroy old RBC
33What does the white pulp contain?
lymphoid tissue arranged around arterioles in periarteriolar lymphoid sheath (PALS)
34What does PALS contain?
T cells
35What is a primary follicle within white pulp?
hasn’t been exposed to antigen yet
36What is the purpose of marginal zone (within white pulp)?
dendritic cells to trap antigen
37What is attached to PALS?
primary follicles which contain B cells that are not yet stimulated by antigen
38What is the purpose of lymph nodes?
filter fluid from the tissues
39What are mucosal surfaces and what is its the purpose?
in respiratory and alimentary tracts backed with lymphoid tissues as additional means of contacting foreign antigens as they enter body
40What controls the circulation of lymphatic fluid?
cytokines (substances that help push immune reaction)
41What is the outer layer of lymph nodes consist of?
mq, mature, resting B, not exposed to antigen yet , and follicular dendritic cells
42What is the purpose of follicular dendritic cells?
in outermost layer to help capture antigen
43What 2 ducts does the lymph get delivered to?
right lymphatic duct or thoracic duct
44What is the purpose of right lymphatic duct?
drains the lymph from the right upper arm and the right side of head and thorax
45What is the purpose of the thoracic duct?
receives lymph from the rest of the body
46Where does the lymph empty?
into venous circulation at or near the junction of internal jugular vein and right and left subclavian vein
47What is the main function of lymph nodes?
filtration
48What are sinuses in the lymph node?
lined with mq creating an ideal location for phagocytosis to take place
49How is the lymph node organized?
outer, paracortex, and inner medulla
50What happens in lymph nodes after differentiation occurs?
mature T and B lymphocytes are released from the bone marrow and thymus
51What is the central collecting point for lymph fluid?
lymph nodes
52What is the best environment for contact with antigen that penetrates into tissue?
lymph nodes
53Where do lymphocytes or any foreign antigens enter lymph nodes?
afferent lymphatic vessels or from high endothelial venules (HEV)
54What are secondary follicles known as?
germinal centers
55What does germinal centers consist of?
antigen-stimulated proliferation B cells
56Where does the transformation of B cells take place?
germinal centers
57What happens to B cells in germinal centers?
form plasma cells and memory cells when exposed to an antigen
58Where do lymphocytes and fluid exit?
efferent lymph vessels
59Where do lymphocytes enter nodes from bloodstream?
high endothelial venules (HEV) in paracortical areas
60Where do T cells primarily concentrate in lymph nodes?
paracortical area, close proximity to APC
61Where are B cells found in lymph nodes?
found in primary follicle and secondary lymphoid follicle (germinal center)
62What surrounds lymph node?
tough outer capsule
63What is underneath the capsule of lymph node?
subcapsular sinus
64What happens are subcapsular sinus?
lymph fluid drains from afferent lymphatic vessels
65What does outer cortex of lymph node contain?
collections of B cells in primary follicles
66What happens when the B cells are stimulated by antigens in lymph node?
secondary follicles are formed
67What does follicular dendritic cells do?
capture antigens and receptors for antibodies
68What is HEV?
high endothelial venules, site where bloodborne lymphocytes can enter lymph node parenchyma
69Where do naïve B and T cells enter (particular and soluble antigen along with dendritic cells)
HEV
70What enters through afferent lymphatic vessels?
incoming lymph, lymphocytes, and foreign antigen
71What exits through efferent lymphatic vessel?
outgoing lymph
72What do secondary follicles contain?
antigen-stimulated proliferation B cells
73What happens following initial encounter with free or cell-associated antigen?
antigen-specific B cells are concentrated at the follicle T-cell-zone border
74What is an important site of T-cell activation?
T-cell-zone border region
75What are the additional areas of lymphoid tissues?
MALT, tonsils, appendix, and cutaneous-associated lymphoid tissue
76Where is mucosal-associated lymphoid tissue (MALT) found?
found in gastrointestinal, respiratory, and urogenital tracts
77What are Peyer's patches?
represent a specialized type of MALT, located at lower ileum of the intestinal tract