Histology
Second stage ( 2016-2017 )Lab. 4
Lymphatic system
lymphatic vessels
resemble the venule but differ in 1- its larger 2- contain more valve
lymphatic vessels
lymph node :
consist of cortex and medulla
Cortical zone:
A-The outer cortex, situated under the capsule, consists of : 1. A diffuse population of cells composed mainly of T lymphocytes , Macrophages ,APCs reticular cells and reticular fibers and ground substance produced by the reticular cells. 2. Lymphoid nodules
Primary nodules & secondary nodules
L.N
SPLEEN
consist of white and red pulps
SPLEEN
THYMUS:
divided into many lobule
THYMUS :
each lobule consist of outer deep zone( cortex) and inner pale zone ( medulla)
Hassal's corpuscles ( thymic corpuscles ):
It is spherical lamellated structures about 30-150 µm in diameter formed of central acidophilic hyalanized area surrounded concentrically arranged, flattened epithelial reticular cells that become filled with keratin filaments
palatine tonsile:
1- covered by stratified sequamous epithelium -2-Each tonsil has about 10-20 crypts3-composed of dense lymphoid tissue in a form of lymphatic nodules
Pharyngeal Tonsil:
1 covered by ciliated pseudostratified columnar 2- no crypte-
Pharyngeal Tonsil:
