thymus and spleen ( anatomy) Flashcards
thymus
primary lymph organ –> maturation and proliferation of cells of the immune system
location of thymus
anterior and superior mediastinum
whats involution?
basically when thymus degenerates and is replaced by fat and connective tissue in adult ( some say start after puberty some at )
thymus develops from what?
third pharyngeal pouch with contribution from fourth
thymus epithelial cells secrete hormones what are they + function >?
thymosin
thymylin = T cell maturation
thymopoeitin = anti aging
what kind of tissue is capsule of thymus made from?
dense irreg CT
cells of the thymus
Pneumonic FELT MAD at MGk and Pd
FELT = fibroblasts epithelioreticular cells lymphocytes thymocytes
MAD = mast cells adipose cells dendritic cells
MGk = macrophages granulocytes
Pd = plasma cells
in the early stage of T cell differentiation aka double negative whats found on the cell surface?
CD2 and CD7
in the middle stage of t cell differentiation whats found on the cell surface?
CD1 2 and 7
in the double positive whats found on the cell surface?
TCRS CD3 4 8
3 major elements of blood thymus barrier
capillary endothelium with basal lamina
peri vascular CT with macrophages and pericytes
type I epithelioreticular cells
type I ERC
form blood thymus barrier
type ii erc
compartmentalize cortex and facilitate T lymphocytes to mature and educate
have MHC I and II
type iii erc
form functional barrier between cortex and medulla
have MHC I and II
where are types 1-3 erc found
in cortex but iii at cortex medullary junction
