Lymphatics Flashcards
List the three functions of the lymphatic system
- Tissue drainage & return of plasma and plasma proteins
- The transport of absorbed fat transport from the gut
- Immunity
Is lymphatic drainage an active process?
Fluid is forced into nearby lymphatic vessels by muscle contraction and lower pressure inside the lymph vessels (it is not an ACTIVE flow)
In normal circulation, around _L of fluid is recirculated through lymphatic vessels every day
In normal circulation, around 8L of fluid is recirculated through lymphatic vessels every day
How is lymph drainage unilateral?
Lymph vessels have valves
What happens to fluid flow out of cells into extracellular spaces during infections?
It increases due to protein accumulation
Where in the body do you find groups of lymph nodes?
At the bases of major arteries
Explain how lymph and lymph nodes play a role in immunity
Lymph nodes are important in acquired immunity. Lymph fluid picks up antigens and takes them back to the lymph node. Within th lymph node, T & B lymphocytes begin to raise an immune response.
Where in the lymph node does the immune response take place?
In the germinal centre
Name the structure that separates the lymph node into segments and stabilises the whole structure
A fibrous capsule made of collagen
Describe how lymph nodes can be involved in cancer
Primary tumours (lymphomas) such as Hodgkin’s are caused by lymphocytes and directly affect the lymph nodes
Secondary tumours as a result of metastasis from other sites can be detected in lymph nodes. This is because tumour cells break away from the primary tumour and move freely in the extracellular space. Once they have entered the extracellular space, they are picked up by lymph vessels and taken to the lymph nodes. Once they have reached the lymph node they often begin to proliferate again.
What is inflammatory hyperplasia?
the term given to enlargement of th lymph nodes.
What drainage routes does lymph follow?
As a rule, deep, lymphatic drainage follows routes of arterial supply.
Ultimately all lymph congregates into __ large lymph ducts
Ultimately all lymph congregates into 2 large lymph ducts
Name the two large lymphatic ducts and the areas of the body that they drain
- Right Lymphatic Duct a very short duct which drains lymph from the upper right quadrant of the body into the right subclavian vein at junction with jugular V
- Thoracic Duct is much larger and longer. It drains the rest of body’s lymph fluid (3/4ths) back into the blood stream through the left subclavian vein
Explain how lymph transports fat from the blood
- Inside a villi, a lacteal absorbs fatty acids and drains into a lymphatic vessel
- Lymph vessels in the intestine are located inside the villi
- Lymph returning from the small intestine is laden with absorbed fats, which will also drain
- Left subclavian vein to superior vena cava onto the liver to be absorbed to the SVC and eventually to the liver for absorption.
