lymphatic system Flashcards
(39 cards)
Function of the Lymphatic System
- Drain excess interstitial fluid
- returns to the blood stream and maintains blood volume - Transport dietary lipids
- Carry out immune responses
How to lymphatic capillaries differ from blood capillaries
- greater permeability
larger in diameter - closed at one end
- allow fluid in but not out
- close proximity to blood capillaries
What do the one way swinging doors on lymph capillaries do
- if pressure surrounding the vessel is higher it opens allowing fluid in until pressure is equal
What is a lacteal
specialized lymphatic capillaries that absorb fat
What are lympatic vessels
- resemble small veins with thin walls and more valves
- along the vessels are lymph nodes
What are lymphatic trunks
as lymph vessels exit nodes they join to form trunks
- Lumbar 2
- Intestinal 1
- Bronchomedial 2
- Subclavian 2
- Jugular 2
What does the Lumbar Trunk get lymph from
- lower limbs
- pelvis
- kidneys
- adrenal glands
- abdominal wall
What does the subclavian trunk get lymph from
- upper limbs
Where do lymphatic trunks drain into
- right and thoracic ducts
What is the thoracic duct & where does it start
- L2 (cisterna chyli)
- 3 trunks empty right there
Where does the thoracic duct drain into
- venous blood at the junction of left internal jugular veins and subclavian veins
What drains into thoracic duct
- R/L lumbar
- intestinal
- L jugular
- L subclavian
- L bronchomediastinal
What drains into right lymphatic duct
- R jugular
- R subclavian
- R Bronchomediastinal
Where does right lymphatic duct drain into
- Right internal jugular vein and subclavian
How does thoracic duct get through diaphragm
- aortic hiatus
Label
How is lymph formed
- excess fluid thats filtered by blood capillaries than reabsorbed
- 3L/day
- return any protiens that may have been lost by blood
Decribe the flow of lymph and mechanisms used
- Skeletal muscle pump
- Respiratory pump
- more valves than veins
- no assistance from heart thus takes lymph hours to circulate
2 types Immune Response of the lymphatic system
- Primary lymphatic organs
- Secondary lymphatic organs
Primary Lymphatic Organs
- stem cells divide and become competent
1. Red bone marrow (B lymphocytes and pre T- lymphocytes)
2. Thymus - pre T lymphocytes migrate to thymus to become immunocompetent
where is the Thymus
- mediastinum between aorta and heart
What functions does the thymus have
- endocrine and lymphatic function
Secondary Lymphatic Organs
- sites where immune response occurs
- Lymph nodes
- Spleen
- Lymphatic Nodules and follicles
Function of Lymph nodes
- act as filters
- trap macrophages trap and destroy foreign bodies
- lymphocytes destroy others by immune response
- lymph passes through many filters before the returning to the blood
