lymphatics Flashcards
what is a lymph?
a tissue fluid that has not yet entered
blood capillaries
composition of lymph?
Similar to plasma,
– contains plasma proteins, dissolved gases,
lymphocytes, bacteria and other pathogens
– Contains fat
what does lymph do
Transports plasma proteins from capillary
beds back to blood stream
▪ Removes larger particles (e.g. bacteria & cell
debris) from damaged tissues – filters and
destroys them in nodes
what are lymph-capillaries ?
Blind-end tubes in interstitial spaces,
larger diameter than blood capillaries
▪ Single layer of endothelial cells which are
very permeable in one direction.
what do lymph-capillaries join up to form?
larger lymph vessels
All tissues of body have network of
lymph vessels expect for?
CNS and outer skin
semi-lunar valves within lymph vessels have a…
one way flow towards thorax
what is the movement of lymph determined by?
skeletal muscle movement
what are the 2 large ducts called?
thoracic duct & right lymphatic duct
what do the 2 ducts drain into?
Subclavian vein
functions of the lymphatic system
Tissue drainage Absorption in the small intestine Immunity 2 groups: Primary lymphatic organs eg bone marrow Secondary lymphatic organs eg lymph nodes
lymph nodes
▪ Oval or bean shaped – approx 600 in the body ▪ Deep & superficial ▪ Size pin-head to small almond ▪ Lie along vessels often in groups ▪ Lymph drains through a number of nodes (usually 8 to 10) before returning to venous circulation
Afferent
inward
Efferent
outward
what is the Parenchyma divided into
cortex & medulla
what cells does Lymphatic tissue contain
B- & T-lymphocyte
Body consists of…
reticular fibres + lymphatic tissue
Capsule ‘dips’ into body to form…
Trabeculae
lymph nodes have a..
Outer fibrous capsule
what are the Capsule, trabeculae , reticular fibres &
fibroblasts
Stroma (support)
functions of lymph nodes
Filtering
Phagocytosis
Proliferation of Lymphocytes
where is the thymus located
between sternum & aorta, between
lobes of lung & above heart in mediastinum
thymus
Bi-lobed organ with capsule and trabeculae
that divide lobes into lobules
lobules have a…
outer Cortex & inner Medulla
where do T-cells mature
thymus
colour of the spleen
purple
where is the spleen located
Lies in abdominal cavity in left hypochondriac region.
functions of the spleen (4)
Phagocytosis
Blood Storage
Immune response
Erythropoiesis
what is MALT
Mucosa-associated lymphoid tissue
Where is MALT found
respiratory, gastrointestinal &
genitourinary tract
what are Peyer’s patches
small masses of lymphatic tissue found throughout the ileum region of the small intestine.
