lymphatics Flashcards
What system is lymphatics in?
Circulatory system
What are the three groups of palpable lymoh nodes?
Cervical nodes
axillary nodes
inguinal nodes
Describe cervical nodes
Lie in a chain on either side of the neck. They drain all structures of the head and neck (swollen glands when you have a throat infection)
Describe auxiliary nodes
Lie scattered in the fatty tissue packing axilla, they drain the upper limbs, thoracic and abdominal wall down to the level of the umbilicus.
Describe inguinal nodes
Lie in the superficial fascia just below the inguinal ligament in the groin. They drain lymph from the lower limb, perineum and external genetalia, the abdominal wall inferior to the umbiculus and the gluteal region posteriorly
Describe the formation of lymph
The cells of the body are bathed in interstitial fluid that is ofrced out of the cappiliares due to hydrostatic pressure of the blood at the arterial end of the capillaries.
This is then returned to the venous side of the capillary bed due to osmotic pressure to prevent the fluid build up (this is regulated by the lymphatic system).
This extra fluid can then pass into surrounding lymohatic capillaries and is now reffered to as lymph
Where does the lymph eventually go
Large veins in the neck, on the left = thoracic duct, on the right = right lymphatic duct.
These both empty into the venous cirvulation at the junction between the internal jugular and subclavian veins. Blockage of these lymph vessels can lead to lymphodema or otherwise known as fluid retension.
Where are lymph nodes located
Along the lymphatic vessels
What is the role of lymph nodes
They act as filters within the immune system and contain B and T lymphocytes that recognise foreign antigens and mount an immune response.
How can lymph nodes be involved in the spread of cancer
Malignant cells may become detached from a primary tumour and can be carried along lymph vessels until they reach a lymph node where they give rise to a secondary tumour. (this is known as metastasis)
