Embryology Flashcards
6 Primary lymph sacs
2 jugular
2 iliac
1 retroperitoneal
1 cisterna chyli
2 jugular
head, neck, upper limbs
2 iliac
lower trunk and lower limbs
retroperitoneal and cisternal chyli
primordial gut
Development of lymph nodes
LEC leave blood vessels
Aggregate to form lymph sac with groups of mesenchyme
form lymphatic nodules
nodules become surrounded by sinuse, with mesenchyme completing the lymph node
Lymphatic cells migrate from the mesenchyme, thymus (prebirth) bone marrow
Spleen embryo
Aggregation of mesenchyme in the dorsal mesogastrium
Palatine tonsils embryo
2nd pharyngeal pouch
Tubal tonsils embryo
from lymph nodules around pharyngeal openings of the pharyngotympanic wall
Pharynheal tonsils embryo
aggregation of lymph nodules in the root of the tongue
Lymph node
Cortex- contains germinal centers with B cells, light inner area, dark outer area
Paracortex- bridge between cortex and medulla
Medulla- medullary cords, trap and eliminates most of bacteria, medullary sinuses open space fed by afferent
Thymus
Lobules and connective tissue septa, thin capsule
No lymphatic nodules
no afferent vessels
Thymus cortex contains
thymocytes
macrophages
dendritic cells
reticular cells
Thymus medulla contains
Naive T cells
Macrophages
Reticular cells
Make swirling Hassal Corpuscle
Spleen
large and highly vascularized Superior left abdominal quadrant Thick connective tissue capsule- invades to form trabeculae NO cortex or medulla Has a red and white pulp
Spleen White pulp
Associated with central artery (immune)
Has germinal centers with a lot of B cells
Some nodules act as a germinal center (mostly inactive B cells)
