Tri A - Lymphatic System Flashcards
What are the components of the Lymphatic System?
Lymph,
Lymphatic Vessels,
Lymphocytes,
Lymphoid Nodules,
Tonsils,
Mucosa,
Lymph Nodes
What are the functions of the Lymphatic System?
Removes waste products, bacteria, abnormal or damaged cells
Drains interstitial fluid from extracellular tissue space
Describe Lymph
Clear, milky fluid - formed when interstitial fluid enters lymphatic capillaries
Similar composition to plasma - less plasma proteins and more lymphocytes
Describe the structure of lymphatic capillaries
A single layer of overlapping epithelial cells
Describe the journey made by Lymph through the body
Blood Capillaries
–>Interstitial Spaces
–>Lymphatic Capillaries
–>Lymphatic Vessels
–>Lymphatic Ducts
–>Subclavian Veins
What are the 3 classes of lymphocytes?
T cells - destroys foreign bodies
B cells - secrete antibodies
NK - natural killers
What is the function of lymph nodes?
To filter out waste and harmful substances
Describe lymph nodes
Capsule of connective tissue
Connected to lymphatic system via afferent and efferent vessels
3 sections: cortex, paracortex, medulla
What is the function of lymphoid nodules?
Contribute to defence against infection
Describe lymphoid nodules
Small areas of densely packed lymphocytes
What is the function of the Spleen?
Phagocytosis,
Storage of blood,
Immune response
Describe the structure of the spleen
Oval shaped - 12x2.5 cm
Formed of reticular and lymphatic tissue
Enclosed in fibroelastic capsule
‘Splenic pulp’ consisting of macrophages and lymphocytes
What is the function of the Thymus Gland?
Transforms lymphocytes into T cells
Describe the structure of the Thymus Gland
weighs 10-15g at birth, grows, then declines again
