Flashcards in Lecture 32: Lymphoid Organs and Tissues Deck (22):
Primary: Bone Marrow, Thymus
Secondary: Lymph nodes, spleen, MALT (mucosa associated lymphoid tissue)
Bone Marrow gives rise to
T cell precursors and mature B cells.
Where do T cell precursors mature?
In the thymus
Two types of T cells
Helper T cells --> activate cytotoxic t cells
Cytotoxic T cells, kill tumor cells, virus-infected cells, etc by contact
Function of B cells
transform into plasma cells. Kill by secretion of antibodies, humoral immunity.
Thymus is active/formed when
Well-formed before birth, active until puberty at which point it turns into fatty mass. Made of two lobes
Each lobe has lobules.
Each lobule ahs cortex ad medulla.
What are Capsule and CT septa?
Lymphatics of thymus
No afferent lymphatics, but has draining efferent lymphatics which drain the capsule and CT septa.
Layers of lobule of thymus?
Outer cortex --> inner cortex --> medulla