Summary ANATOMY OF THE THYMUS GLAND

THYMUS THYMUS GLAND • Located behind/posterior to the manibrium sterni • Thymus gland has two parts:- • The cortex: that has  densely packed T-lymphocytes • The thymus is equipped with a blood-thymus barrier, which is restricted to the cortex • Medulla has: Less densely parked T-lymphocytes It has hassal corpuscles It is enclosed by a higly vascularized tissue capsule Thymus under low magnification   Cortex and medulla The cortex • It consists of:- a) Thymocytes: are Densely parked mature T-cells b) Thymic epitheliocytes:-  these epitheliocytes form cellular meshwork into which the Tcells are tightly parked  they secrete hormone thymosin, serum thymic factor and thymopoetin which transform the immature thymocytes to mature T-Lymphocytes  They also produce thymotaxin that attract progenitor Tlymphocytes from the bone marrow Hassall corpuscles: in the thymus medulla. They consist of several concentric layers of reticulum cells in an arrangementreminiscent of an onion