Lymphatics Flashcards
Give the main functions of the lymphatic system
Tissue drainage
Return of plasma and plasma proteins
Absorbed fat transport from gut
Immunity
What are the main constituents of the lymphatic system?
Lymphatic vessels Lymphatic tissues (spleen/thymus/tonsils/nodules)
How do lymphatic vessels differ from blood vessels?
They can also absorb proteins and other large molecules from tissue fluid
What is lymph made up of?
Tissue fluid and plasma proteins, and later lymphocytes and fats
How does tissue fluid find itself in the extracellular space?
Leaks out of blood vessels due to high hydrostatic pressure as circulation moves from the large vessels of the heart to smaller blood vessels
How does lymph flow in lymphatic vessels?
Reliance on muscular contractions, pressure changes and gravity
Unidirectional - presence of valves
Flow increases into ECF during infection due to protein accumulation (osmosis)
How does tissue fluid move from the extracellular space to the lymphatic vessels?
Through physical gaps in the vessel walls
What are the functions of lymph nodes?
Gives lymph its immunological functions
Adds lymphocytes and antibodies to lymph if bodily antigens are detected
Filter out inert particles from lymph (e.g. carbon)
How are antibodies given time to form in the lymph nodes?
Flow rate decreases after flow from a small to a large vessel
Describe the drainage route of lymph in the limbs
Superficial follow superficial veins, e.g. skin
Deep follow deep arteries and veins, e.g. muscles/tendons
Fascia between deep and superficial is impervious to fluid
Describe the drainage route of lymph in the cavities
Follow deep arteries
Give example of parts of the body where there are no lymphatic vessels
Eyeball CNS Inner ear Cartilage Bone
What is the role of the saphenous opening in the inguinal region?
Allows superficial drainage to reach the deep drainage of the lymphatic system
Describe possible pathologies of the lymph node
Primary tumours e.g. Hodgkin’s lymphoma
Secondary tumours from metastasis
Infections e.g. TB/glandular fever
Inflammatory hyperplasia (enlargement)
Where does collected lymph ultimately congregate?
Right lymphatic duct
Thoracic duct
