Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Lymphatic System
UCI Histo test 3
| Question | Answer |
|---|---|
| 3 purposes of lymphatic system | immune response, maintenance of body fluids, extramedullary heatopoiesis |
| lacteals | lymphatic capillaries |
| are lymphatic vessels fenestrated? | NO |
| flow of lymph | lymphatic capillaries to lymph vessels to lymph nodes to right lymphatic duct or thoracic duct |
| what is the largest lymph vessel in body | thoracic duct |
| where do the right lymphatic duct and thoracic duct drain | right and left subclavian veins respectively |
| structure of lymphatic cappillaries | single layer of attenuated endothelial cells with an incomplete basal lamina |
| what is lymphedema | elephantitis |
| causes of lymphadema | genetic or injury to lymphatic vessels (surgery, radiation therapy (breast cancer particularly); filariasis; cellulitis |
| filariasis | a parasitic infection causing lymphedema |
| treatment for lymphedema | decongestive therapy, compression, use of home sequential gradient pumps |
| lymphangitis | lymph vessel inflammation (usually streptococcus) from bacterial infection of lymphatic system; can lead to septicemia; can come from tumors, mastectomy, leg vein removal, or tinea pedis (foot fungus infection) |
| what do NK cells do | kill tumor cells, virally infected cells, bacteria, and parasites |
| which immune system is majorly affect by the lymphoid system | adaptive (innate is not) |
| IgD | activates B-cells |
| IgE | degranulates mast cells and basophils |
| IgG | opsonin, NK cytotoxicity |
| primary lymphoid organs | Thymus, prenatal/postnatal bone marrow, fetal liver |
| secondary lymphoid organs | lymph nodes, spleen, MALT, postnatal bone marrow |
| Encapsulated (dense) lymphatic organs | thymus, lymph nodes, spleen |
| unencapsulated (diffuse) lymphatic organs | MALT, BALT, GALT, tonsils |
| MALT, BALT, and GALT stand for what | mucosal associated lymphoid tissue, bronchial..., gut... |
| function of thymus | immunological competence of T cells, elimination of self-reactive T cells, and MHC (HLA) recognition |
| thymic lobes | 2 lobes arising from endoderm and mesoderm |
| lobules | incomplete divisions of the lobes formed by septa (trabeculae) |
| trabeculae | septa |
| thymus capsule | dense collagenous connective tissue covering the thymus |
| cortex of thymus | T cell education, elimination of self-reactive T cells, MHC recognition; contains thymocytes, macrophages, and epithelial reticular cells; appears dark due to lots of T cells |
| thymocytes | immature T cells in the cortex to be educated |
| 2 steps of cell instruction in the cortex of thymus | 1)maturation stimulate by hormones produced by epithelial reticular cells 2)testing the ability to recognize self-MHC I/II and self epitopes (mediated by type II/III epithelial reticular cells and bone marrow dendritic APC's |
| function of macrophages in cortex | phagocytose apoptosed T cells |
| how many lymphocyte clones are formed during embryonic development | 10 quadrillion |
| two ways to take out self-reacting t-cells | clonal deletion and anergy (inactivation) |
| TCR complex is composed of what | CD3 and either CD4 or CD8 |
| medulla of thymus | lightly stained; full of Hassall's corpuscles and immunocompetent T cells |
| how do T cells leave medulla | via venules and efferent lymphatic vesseles; migrate to secondary lymphatic structures |
| hassall's corpuscles | composed of type VI epithelial reticular cells; increase with age; fxn unknown |
| reason for blood-thymus barrier | prevent developing T cells from contacting blood-borne macromolecules |
| how does the blood get to the thymus | vessels go through the trabeculae into the corticomedullary jxn, where they form capillary beds that penetrate the cortex |
| thymic cappilaries have what three features | a continuous endothelium, a thick basal lamina and adjacent epithelial reticular cells |
| what can cross the blood thymus barrier | self-macromolecules to participate in self-recognition of T-cells |
| Epithelial reticular cells in the Cortex (Types I-III | Isolate the Cortex of the thymus and prevent maturing T cells / Thymocytes from exposure to foreign antigens. Synthesize hormones (thymosin, serum thymic factor, and thymopoietin) that contribute to thymocyte maturation. |
| Epithelial reticular cells in the Medulla (Types IV-VI) | Assist in isolating the Cortex from Medulla (Type IV) to prevent maturing T cells / Thymocytes from exposure to foreign antigens. Type VI form Hassall’s corpuscles. |
| Thymic involution | atrophy of the thymus with age |
| lymph node size and contents of parenchyma | <3cm; T cells, B cells, APC's and macrophages |
| type of lymph vessel valves | semilunar |
| flow of lymph in lymph vessels | afferent lymphatic vessels, subcapsular sinuses, cortical sinuses (paratrabecular) which parallel the trabeculae, medullary sinuses, efferent lymphatic vessels |
| location and purpose of high endothelial venules in lymph node | in the paracortex; provide acces for lymphocytes to enter lymph node from vascular system |
| postcapillary venule location and purpose in lymph node | located in cortex; provide exit for lymphocytes from the lymph node into the vascular system |
| lymph node capsule | collagenous connective tissue surrounding lymph node; forms trabeculae upon vagination into lymph node |
| lymph node trabeculae | subdivide the outer lymph node cortex into incomplete compartments |
| cortex of lymph node | subdivided by trabeculae; houses B cell rich primary and secondary lymphoid nodules |
| primary cortical lymphoid nodules | spherical aggregates of virgin and memory B cells in the process of entering/leaving the lymph node |
| secondary cortical lymphoid nodules | pale staining and houses a germinal center; form from antigenic challenge, sites of memory B cell and plasma cell generation |
| lymph node corona | adjacent to a germinal center; composed of a dense accumulation of lymphocytes migrating away from their site of origin |
| dark zone in secondary cortical lymphoid nodules | site of intense B cell proliferation |
| light zone in secondary cortical lymphoid nodules | where proliferated B cells migrate, express Igs, do class switching, are exposed to antigen-bearing follicular dendritic cells, and are killed if they fail; survivors exit as memory B's or plasma cells |
| paracortex of lymph node | houses T cells (thymus dependent); location of adaptive immune response |
| steps of paracortex adaptive immune response | T cells migrate by the HEVs, Dcs/APCs migrate to paracortex to present their epitope-MHC complexes to T-helpers; T-helpers proliferate and expand the paracortex; T-h migrate to medullary sinuses, and exit the node |
| medulla of lymph node | large, convoluted lymph sinuses surrounded by lymphoid cells that are organized in clusters called medullary cords |
| medullary cords | located in lymph node medulla; contain lymphocytes, plasma cells and macrophages; lymphocytes must go through the medullary sinuses to exit the node via the efferent lymphatic vessels |
| fxns of spleen | filter blood, form lymphoid cells, eliminate blood-borne antigens, destroy old platelets and RBCs, fetal hematopoiesis, possible adult hematopoiesis |
| capsule, trabeculae, and hilum of spleen | just like the same in the lymph nodes |
| function of red pulp of spleen | filter the blood |
| components of red pulp of spleen | splenic sinuses and splenic cords of billroth |
| white pulp | PALS housing T cells and lymphoid nodules housing H cells |
| trabecular arteries in spleen | source of PALS |
| PALS | periarterial lymphatic sheath |
| trabecular arteries and PALS | trabecular arteries get smaller and smaller until they turn into PALS |
| PALS composed of | T cells to watch the blood |
| central artery | the vessel occupying the center of the PALS |
| penicillar artery | where the central artery terminates it loses its PALS and divides further into a series of short parallel branches, called penicillar arteries, which enter the red pulp |
| lymphoid nodules of spleen | found in white pulp; enclosed within the PALS, composed of B cells; displace the central artery to a peripheral position; may display germinal centers, indicating atigenic challenge |
| marginal zone in spleen | separates white pulp from red pulp composed of mainly B cells but also plasma cells, T cells, macrophages, and APC; this is the location where APC contact the blood |
| Splenic reticular fiber network | attached to the capsule and trabeculae; puts the right type of cells in contact with eachother |
| MALT | mucosal associated lymphatic tissue; nonencapsulated lymphoid nodules in the mucosa of th GI, respiratory, and urinary tracts; response to airborne/injected antigens; GALT, BALT, tonsils |
| GALT | gut associated lymphatic tissue; composed of B cells surrounded by T cells and APCs; no afferent lymph vessels, but efferent lymph drainage is present |
| peyer's patches | GALT in the ileum |
| M cells | microfold cells; found in ileum adjacent to peyer's patches; thought to capture antigens and transfer them to macrophages in peyer's patches |
| BALT | bronchial associated lymphoid tissues; similar to peyer's patches but in bronchi; no afferent vessels; efferent lymph drainage is present; mostly B cells; M cells are also present |
| tonsil | incompletely encapsulated aggregate of lymphoid nodules; mostly T and B lymphocytes |
| what are the three tonsils | palatine, pharyngeal, and lingual |
| palatine tonsils | composed of lymphoid nodules inside 10-12 crypts, which invaginate the tonsilar parenchyma |
| germinal centers are indicative of what and are found where? | indicative of B cell activation by antigen and proliferation; found in tonsil |
Created by:
droid
Popular Histology sets