Lymphatic System Flashcards
What is the function of the Lymphatic system?
Absorption of fluid from tissues with return to circulation
Absorption of fats and fat soluble vitamins
Defense against disease
What are lymphatic vessels?
An extensive network of large pore capillaries and other vessels
Supply all organs except the CNS
Close proximity to veins
Pick up tissue fluid and return it to the circulation
What is lymph?
A liquid composed of tissue fluid and proteins
Flows from capillaries to two lymphatic ducts that drain into the subclavian veins
What are the steps in T cell activation?
Maturation in thymus gland
Antigen presented by phagocyte
Antigen binds with helper T cell and inactivated cytotoxic T cell
Activation of cytotoxic T cell with the help of cytokines from helper T cells
Formation of clones of cytotoxic and memory T cells
What are 5 factors that affect movement of lymph?
Pumping heart
Milking action of skeletal muscles
Changes in thoracic pressure
Contraction of blood vessel
smooth muscle Valves
What are lymph organs?
Lymph nodes
Tonsils
Thymus gland
Spleen
What are lymph node’s?
Patches of lymphatic tissue in clusters
Filter lymph flowing through them
What are 3 large clusters of lymph nodes?
Cervical (neck)
Axillary
Inguinal (groin)
What are lymph nodes?
Compartments (lymph nodules) separated by lymph sinuses
Composed of lymphocytes and macrophages ( wbc responsible for identifying a foreign invader and engulfing them)
What do tonsils do?
Lymph nodes in the throat that filter pathogens from nose and mouth (3 sets, the ones on the side - palatine tonsil are the ones that are removed in surgery)
What is the thymus gland?
In the mediastinum
Shrinks after puberty
Contains lymphocytes
Site of T cell maturation
Secret hormones
Not as important in adulthood
What is the role of the spleen?
LUQ organ
Filters blood
Red pulp (filters blood) and white pulp (lymphatic tissue) cleans blood and destroys microorganisms
Enters via splenic artery and leaves via splenic vein
Stores platelets
Destroys senescent RBC’s
Fetal erythropoiesis (making RBC’s)
How does Lymph flow?
Tissue fluid- lymphatic capillaries- large lymphatic vessels
From there, lymph flows to EITHER the Thoracic duct - left subclavian vein
OR
Right lymphatic duct - right subclavian vein
How much fluid is filtered everyday in the interstitial spaces?
3 Litres , the remainder gets dumped into the lymphatic system
What is lymph composed of?
It is a clear fluid composed of water with dissolved electrolytes, metabolic waste and proteins
How does the lymphatic system move fluid?
Network of vessels pumping the fluid though using skeletal muscle (no pump moving the fluid)
What is the fluid balance (anatomy)
Picks up the fluid that was filtered out through the capillaries and send the fluid though the lymph nodes and dumped back into the veins
Are macrophages phagocytes?
Yes
What presents antigens to the cells of the immune system?
Macrophages
What are 2 characteristics that distinguish specific immunity to non specific immunity?
Specificity
Memory
What functions does the immune system perform?
Recognition of self
Protection from foreign substances
Protection from pathogens
Cell to cell combat
What immunoglobulin sits on the surface of and helps activate B cells?
D
What do neutrophils do?
Injest and digest pathogens in a field of bactericidal chemicals
Are a type of WBC that engulf and destroy pathogens using bactericidal chemicals
Does non specific immunity require memory cell formation?
No
What do complement proteins do?
Poke holes in bacterial cell membranes leading to cell lysis and death
How do antibodies destroy antigens?
They neutralize antigens by binding to them which block the antigens ability to infect cells or mark them for destruction by other immune cells
What is removed during a T and A procedure?
Palatine tonsils
Pharyngeal tonsil
Where do efferent lymph vessels carry fluid to?
Away from the lymph nodes
Wheat percent of tissue fluid is carried away as lymph?
15%
What functions does the spleen perform?
Fetal erythropoiesis
Elimination of old worn out erythrocytes
Production of antibodies
Storage of platelets (help in blood clotting)
What are the functions of antibodies?
They activate compliment proteins
They bind with antigens to form a complex resulting in agglutination
They are effective against bacteria, viruses and toxins
