Embryo Session 12

Front 1

congenital lymphedema

Back 1

Causes:- Dilation of primordial lymphatic channels OR congenital hypoplasia of lymphatic vessels

Diffuse cystic dilation of lymphatic channels rarly involves widespread portions of the body

Front 2

Cystic hygroma

Back 2

cause: abnormal transformation of the jugular lymph sacs

from: Hygromas are believed to arise from parts of jugular lymph sac that are pinched off, OR from lymphatic spaces that fail to establish connections w/ main lymph. channels

Large swellings appear on inferolateral part of neck-hygromas present at birth or grown in infancy

Front 3

Lymphatic system bassics and development

Back 3

-begins at end of 6th week
-start w/ six lymph. sacs
-lymph vessels join sacs
-thoracic duct forms
-lymph nodes develop
-lymphocytes develop
-connect with the venous system

Front 4

lymphatic parts and origins

Back 4

THORACIC DUCT-caudal part of the right thoracic duct AND anastomosis between thoracic ducts and cranial part of left thoracic duct
LYMPH NODES-mesenchymal cells invade sacs and break them up into network of lymph. channels (prim. lymph sinuses)
LYMPHOCYTES-stem cells in the yolk sac mesenchyme origionally, later=from liver and spleen

Front 5

Lymph Sacs

Back 5

at end of embryonic period=6 sacs
2-Jugular L. sacs-near jxn of subclavian veins and ant. cardinal veins
2-iliac L. sacs-near jxn of iliac veins and post cardinal veins
1-retroperitoneal L sac-in root of mesentery on post abdom wall
1-Chyle cistern-dorsal to retroperitoneal L sac