BL - The Lymphatic System Flashcards
How many litres of interstitial fluid a day does the lymphatic system collect?
3 litres
What does the lymphatic system consist of?
FLUID (lymph), VESSELS (lymphatics), CELLS (lymphocytes and supporting cells), TISSUES and ORGANS
How is lymph propelled through the body?
Skeletal muscle movement, pressure changes in thorax during breathing, pulsation of adjacent arteries and veins.
What do larger lymphatic contain in their walls to help lymph flow?
Smooth muscle, which can contract to move lymph along.
What are the two types of tissue found in the lymphatic system?
Diffuse (MALT/GALT/BALT) and lymphatic nodules (Tonsils, Payer’s patches, vermiform appendix)
What does GALT stand for?
Gut associated lymphatic tissue
Which organs are included in the lymphatic system?
Lymph nodes, thymus, spleen
What do lymph nodes do?
They filter lymph as it percolates on its way to the vascular system.
Roughly how many lymph nodes are there n the human body?
700
Each lymph node has a feeding artery and a draining vein. What do these enter and leave via?
The hilum
What are Payer’s patches?
Small masses of lymph tissue found in the small intestine. They monitor bacteria populations and prevent growth of pathogenic bacteria.
Where are follicular dendritic cells located?
Terminal centres of lymph nodes.
What are follicular dendritic cells used for?
Antigen antibody complexes adhere to the dendritic processes and the cell can retain its antigen for months.
What do follicular cells do to B cells?
They cause them to proliferate.
Why do T cells require the help of professional antigen-presenting cells?
They are unable to recognise antigens in the absence of antigen presentation.