Lymph Nodes & Spleen Flashcards
which is a thymus dependant zone?
paracortex
what are the stations for filtration?
lymph nodes
lymphatic capillaries are made up of?
single layer of endothelium and interrupted basal lamina
absence of pericyte is seen in?
lymphatic capillaries
functions of lymphatic vessels
- remove lymph from the interstitial spaces and return it to the blood.
- remove larger molecules which cannot be carried by capillaries as fat droplets and bacteria . this is due to the gaps btw the endothelial cells and interrupted basal lamina
differences of lymphatic vessels with venules
they have larger diameter and thinner walls , have bicuspid valves more numerous than veins, to control the lymph flow in one direction. beaded appearance.
inflammation of lymphatic vessels is called ? their appearance and symptoms
lymphangitis, occurs in the skin as red lines that are painful.
what is the main basic structure of lymphatic tissue?
lymphocytes T and B
what are the primary and secondary lymphatic organs?
1ry - bone marrow and thymus
2ry - lymph nodes , spleen and tonsils.
reticular connective tissue is stained with ____ stain and is ____ in colour?
silver ; brown
1ry lymphatic nodules [follicles] contains?
B- lymphocytes
paracortex contains ?
T - lymphocytes
valves found in lymphatic vessels help the lymph to move in one direction. name the valve.
bicuspid valves
____ enters and ____ leaves the lymph nodes at the hilum.
ateries; veins
the most common cell present in cortex and medulla of lymph nodes?
b - lymphocytes
lymphoblasts and lymphocytes are found in the?
germinal centres
largest single intra abdominal hemolymphatic organ
spleen
in spleen capsule is covered by?
peritoneum
only few afferent vessels are found in the capsule of?
spleen
the capsule of lymph node is covered by?
adipose tissue, fascia, smooth muscles & elastic fibres
the capsule of ____ has many afferent and efferent lymph vessels.
lymph node
the trabeculae is ___ and ___ in ___ and ___ respectively and descends and ascends from ____ & ____ respectively.
thin - lymph node : descends from the surface of the capsule.
thick - spleen : arises from the hilum
trabeculae of spleen is rich in ___ & ___.
elastic fibres and smooth muscles.
the trabeculae divides the spleen into ___ compartments. comment about the trabeculae in the lymph nodes.
- Irregular
- In lymph nodes the trabeculae divides the cortex into regular compartments and the medulla into irregular compartments.
the reticular C.T network of spleen is stained with?
silver
central arteriole aka?
follicular arteriole
what are the four different zones of the central arteriole from inside to outside?
- thymus dependant zone ( PeriArteriolar Lymphatic Sheath) - PALS [ contains T - lymphocytes ]
- germinal centre [ lightly stained central area . formed of B - Lymphocytes , large activated lymphocytes, plasma cells & macrophages ]
- follicular zone [ darkly stained area around the germinal centre contains mainly B - Lymphocytes ]
- marginal zone [ contains T & B - Lymphocytes ]
Red pulp is formed of?
- Splenic cords ( Billroth cords )
2. Blood Sinusoids : Stave cells & Macrophages - Littoral cells.
write a note on open and closed theory of splenic circulation.
Open theory - capillaries open and deliver blood directly into the tissue of the red pulp. blood is collected by passing through openings in the wall of sinusoids.
Close theory - capillaries open directly into the sinusoids.
state about open and closed theory.
spleen contraction - circulation is closed
relaxation - open
functions of the spleen (5 pts)
- Filtration of blood by macrophages
- Storage of blood cells and platelets
- Formation of blood elements in foetal life and lymphocytes throughout the life
- immunological functions ( humoral & cell mediated immunity )
- Destruction of old RBC’s .
elaborate the process of destruction of RBC.
- Heme is broken down into
1. iron : stored in macrophages
2. non - iron : goes to the bile pigments - Globin is broken down into amino acids and goes to the blood.
