tissues & organs forming the immune system Flashcards
primary lymphoid organs (central lymphoid organs)
-bone marrow
-thymus
secondary lymphoid organs (peripheral lymphoid organs)
-spleen
-lymph nodes
-mucosa-associated & skin-associated lymphoid tissue
bone marrow structure
it’s a PLO/generative lymph organ.
is soft, gelatinous tissue that fills the medullary cavities/ center of the bones
types of bone marrow?
red bone marrow (myeloid tissue)
yellow bone marrow (fatty tissue)
2 types of bone marrow stem cells
mesenchymal stem cells
hematopoietic stem cells
red bone marrow
delicate, highly vascular fibrous tissue
has hematopoietic stem cells (blood-forming stem cells)
yellow bone marrow
contains mesenchymal stem cells or marrow stromal cells (produce fat, cartilage, and bone)
location of RBM
skull
vertebrae
ribs
sternum
the end of the upper arm bone pelvis
the ends of the thigh bone
when do humans have bone marrow in all bones?
infants & children less than1 year old
boon marrow function
site for hematopoiesis
site for B-cells production and maturation
site for T-cells production (not maturation)
whats hematopoiesis
generation of the cellular elements of blood
thymus info and location
PLO/encapsulated soft, bilobed organ
chest, anterior to the ascending aorta & posterior to the sternum & between the lung lobes
thymus structure macroscopically
lobulated organ, composed of 2 lobes connected by an isthmus
thymus structure microscopically
capsule
septa
cortex (peripheral)
medulla (center)
corticomedullary junction
thymus function
endocrine function
hemopoietic cells mature into T-cells via negative and positive selection
