Immunology Flashcards
(236 cards)
What the primary lymphoid organs?
Thymus and Bone marrow
What is the function of lymph nodes?
nonspecific filtration by macrophages, storage and activation of B and T cells. Ab production
What does the structure of a lymph node look like?
- many afferents, one efferent
- encapsulated w/ trabeculae
- follicle, medullar, and paracortex
What is found in the follicle of a lymph node?
site of B cell localization and proliferation
- in outer cortex - primary follicles are dense and dormant. Secondary follicles have pale central germinal centers and are active
What is found in the medullar of a lymph node?
- medullary cords (closely packed lymphocytes and plasma cells
- medullary sinuses - communicated w/ efferent lymphatics and contain reticular cells and macrophages
What is found in the paracortex?
- T cells
- this is the region btw follicles and medulla
- contains high endothelial venules through which T and B cells enter from blood
What happens to the paracortex in an intense immune response?
becomes greatly enlarged
What happens to the paracortex in DiGeorge pts?
not well developed b/c they don’t have T cells
What is the lymphatic drainage from the following areas of the body?
- Upper limb, lateral breast
- stomach
- duodenum, jejunum
- sigmoid colon
- rectum (lower portion) of anal canal (above pectinate line)
- anal canal below the pectinate line
- testes
- scrotum
- thigh
- lateral side of dorsum of foot
- axillary
- Celiac
- superior mesenteric
- colonic – inferior mesenteric
- internal iliac
- superficial inguinal
- superficial and deep plexuses –> para aortic
- superficial inguinal
- superficial inguinal
- popliteal
What is considered to be the largest component of the immune system?
MALT - made up by GALT, NALT, BALT, genitourinary tract, appendix, tonsils, adenoids, M cells
What are M cells?
- found in the mucous membranes of small gut
- ## flattened epithelial cells lacking microvilli. there are deep pockets on the basilar side that allow Ag presentation to dendritic cells, B and T cells, and macrophages
What are Peyer’s patches?
- unencapsulated lymphoid tissue
- found in lamina propria and submucosa of small gut
- B cells make IgA
What does the right lymphatic duct drain?
-right arm, right chest, and right half of head
What does the thoracic duct drain?
everything else
Where does the thoracic duct drain?
junction b/w lespift subclavian and internal jugular vein
Describe the sinusoids of the spleen?
long, vascular channels in red pulp w/ fenestrated barrel hoop basement membrane. Macrophages found nearby
Where are T cells found in the spleen?
Periarterial lymphatic sheath (PALS) within the white pulp
Where are the B cells found in the spleen?
follicles w/in the white pulp
What is the role of the macrophages in the spleen?
remove encapsulated bacteria
What happens when there is splenic dysfunction?
- decreased IgM = decreased complement activation = decreased C3b opsonization
- increases susceptibility to encapusulated organisms
What are some encapsulated organisms that you need to worry about when you have splenic dysfunction?
E coli, pseudomonas, strep pneumoniae, Haemophilus influenzae type B, Nessiera meningitidis, salmonella, klebsiella, cryptococcus neogformans, group B Strep
Where are situations that a splenic dysfunction will take place?
- sickle cell pts
- Trauma to spleen
- hereditary sphereocytosis
What happens after postsplenectomy?
- Howell Jolly bodies - nuclear remnants
- Target cells
- Thrombocytosis
What is important about the thymus?
- site of T cell differentiation and maturation
- encapsulated
- from epithelium of 3rd branchial pouch
- Cortex is dense w/ immature T cells
- Medulla is pale w/ mature T cells and epithelial reticular cells containing Hassall’s corpuscles.