Embryology

Question 1

6 Primary lymph sacs

Answer 1

2 jugular
2 iliac
1 retroperitoneal
1 cisterna chyli

Question 2

2 jugular

Answer 2

head, neck, upper limbs

Question 3

2 iliac

Answer 3

lower trunk and lower limbs

Question 4

retroperitoneal and cisternal chyli

Answer 4

primordial gut

Question 5

Development of lymph nodes

Answer 5

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

Question 6

Spleen embryo

Answer 6

Aggregation of mesenchyme in the dorsal mesogastrium

Question 7

Palatine tonsils embryo

Answer 7

2nd pharyngeal pouch

Question 8

Tubal tonsils embryo

Answer 8

from lymph nodules around pharyngeal openings of the pharyngotympanic wall

Question 9

Pharynheal tonsils embryo

Answer 9

aggregation of lymph nodules in the root of the tongue

Question 10

Lymph node

Answer 10

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

Question 11

Thymus

Answer 11

Lobules and connective tissue septa, thin capsule
No lymphatic nodules
no afferent vessels

Question 12

Thymus cortex contains

Answer 12

thymocytes
macrophages
dendritic cells
reticular cells

Question 13

Thymus medulla contains

Answer 13

Naive T cells
Macrophages
Reticular cells
Make swirling Hassal Corpuscle

Question 14

Spleen

Answer 14

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

Question 15

Spleen White pulp

Answer 15

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)

Question 16

Spleen Red pulp

Answer 16

Associated with veins and sinusoids
RIch in blood
Splenic cords contain B cells. T cells, plasma cells, macrophages, other blood cells
Venous sinuses are discontinous capillaries
Reservoir for RBC and platelets

Question 17

MALT consist of

Answer 17

GALT: Peyers patch in ileum, lymh nodules, in appendix/colon
BALT: bronchi and bronchioles

Question 18

Tonsils

Answer 18

Epithelium lining and incomplete capsule

Traps bactereia and viruses, defends against infection, site for lymphocytes to meet antigens

Question 19

4 main tonsils in tonsilar ring

Answer 19

Palatine- between palatopharyngeal and palantoglossal
Tubal- lateral walls of nasopharynx
Pharyngeal (adenoids)- roof of nasopharynx
Lingual- base of tongue