3.02: Lymphatic System Flashcards
(22 cards)
function of lymphatic system
- drains interstitial fluid + returns fluid to blood
- site of maturation of B + T cells
- carries dietary lipids and vitamins from GI tract to blood
what are the primary lymphoid organs?
bone marrow and thymus
what are the secondary lymphoid organs?
lymph nodes + spleen
what does bone marrow do
site of B and T lymphocytes, also where B cells mature
what does thymus do
where T cells mature
lacteal
- found inside lamina propria of villi of ilieum
- absorb dietary fats
Nasal Associated Lymphoid Tissue
Palatine, Pharyngeal, and lingual tonsils
What do tonsils do?
produce antibodies against antigens in local area
- only have efferent lymphatic vessels
What are the lymphoid nodules (outer cortex) of the Lymph node made of?
B Cells
What is the inner cortex of lymph node made of?
T cells and Dendritic cells
what are the medullary cords of the lymph node made of
reticular fibers, plasma cells, b cells, macrophages
what are the medullary sinuses of the lymph node?
capillary like-channels
what is the white pulp of the spleen made of?
B and T cells
important things to remember about the spleen
- has CT capsule and trabeculae
- Not divided into medulla + cortex
- no afferent lymphatic vessels
- blood vessels enter + leave via hilum
red pulp cords
meshwork of reticular cells + blood cells
red pulp sinuses
venous sinuses lined by rod-shaped endothelial cells
Cells of the thymic cortex
epithelial reticular cells, small t cells, macrophages
cells of the thymic medulla
Epithelial reticular cells, large T cells, Hassells Corpuscle
what cells are found in the parynchema of the thymic cortex?
Thymocytes (darker) + Lymphoblasts (lighter)
what cells are found in the stroma of the thymic cortex?
capsule + epithelial reticular cells
Characteristics of Hassalls Corpuscle
- keratohyalin granules (black )
- keratin fibers (pink lines)
What happens to the thymus over time?
Hassalls corpuscles expand + accumulate fat, thymus degenerates
