anatomy of lymphatic system Flashcards
What are the components of the lymphatic system?
- lymphatic vessels
- lymphoid tissue
- lymphoid organs
What do lymph vessels in the brain do?
carry fluid (lymph) and immune cells from cerebrospinal fluid deep cervical lymph nodes
what are the roles of the lymph system?
- drains extracellular fluid
- transports dietary lipids and fat soluble vitamins
- initiates and carries out specific immune responses§
How does lymphatic system stop lymph leaking into interstitial space again?
lymphatic capillary walls overlap so tissue fluid can enter it but not leave it
Why is the lymphatic system called an open system?
It has a defined start and end point
Hoe does the lymphatic maintain fluid balance in the body?
reabsorbs fluid not taken up by venous end of capillaries
structure of lymphatic vessels
- thinner walls than veins
- more valves to ensure unidirectional flow of blood
what is lymph from the gastrointestinal tract called?
chyle
what does chyle include that regular lymph might not?
rich in lipid molecules absorbed after a meal (especially triglycerides)
what are the vessels that collect chyle called?
lacteals
which system does lymph empty into?
venous circulation system
what is the biggest lymph vessel?
thoracic duct
which parts of the body drain into the thoracic duct?
left and right lower limbs, pelvis, abdomen, left side of thorax and left side of head and neck
where does the thoracic duct empty into?
left brachiocephalic vein (where left jugular and left subclavian vein join)
which parts of the body drain into the right lymphatic duct?
right side of the face and neck
where does the right lymphatic vein drain into?
right brachiocephalic vein (where the right subclavian and jugular vein meet)
What is the cistern chyli?
present just before the thoracic duct
approximately where is the cistern chill found?
near first lumbar vertebra, close to the aortic opening of diaphragm
where does cisterna chyli receive lymph from?
lumbar lymphatics and gastrointestinal tract (lacteals)
what causes primary lymphoedema?
malformed or absent lymphatic vessels caused by inheritance
what causes secondary lymphoedema?
- excessive accumulation of interstitial fluid
- obstruction of lymphatic vessels
- lack of skeletal muscle contraction
where is it common to find lymphoid tissue?
in connective tissues of mucous membranes or wherever pathogens can enter the body
give examples of where you may find lymphoid tissue?
- urinary tract
- reproductive tract
- respiratory airways
- gastrointestinal tract
- appendix
name 2 types of lymphoid tissue
- tonsils
- aggregated lymphatic follicle (Peyer’s Patches)
where can you find Peyer’s Patches?
ileum
difference between lymphatic tissues and organs
lymphatic organs are encapsulated and distinct
what are the primary lymphatic organs?
bone marrow and thymus
Role of bone marrow
consists of pluripotent stem cells that can develop into RBCs and WBCs, including T and B-lymphocytes
role of the thymus
where t-cells mature in children
where can the thyme be found?
behind the sternum, above the heart
what are the secondary lymph organs?
- lymph nodes
- spleen
where are lymph nodes located?
along the course of lymphatic vessels
role of lymph nodes
where b-cells mature
what is the importance of lymph vessels in cancer?
secondary tumour sites predicted based on direction of lymph flow from primary tumour site since metastasis can occur via lymph vessels
importance of lymph nodes in cancer?
spread of cancer to lymph nodes suggests how far the cancer has progressed
function of the spleen
breaks down RBCs, stores lymphocytes
where can you find the spleen?
underneath the left dome of the diaphragm, under ribs 9, 10 and 11
what is splenomegaly?
enlarged spleen
what can cause splenomegaly?
- increased work-load due to infection e.g. sickle cell, leukaemia
- liver diseases since they share a drainage system
symptoms of splenomegaly
pain in abdomen, chest and back
