Lymphatic Structures
What are the 3 main functions of the lymphatic system?
Transport excess fluid, absorb fats, defend against disease
What causes tissue fluid to enter lymphatic capillaries?
Increased tissue fluid pressure
What are the two main types of immunity?
Innate (nonspecific) and Adaptive (specific)
Where do T cells mature?
In the thymus
What is lymphedema?
Fluid buildup from blocked lymph flow
What are lacteals?
Lymphatic capillaries that absorb fats from intestines
How does muscle movement affect lymph flow?
Muscle contractions push lymph through vessels
What is the first line of defense?
Skin and mucous membranes
Which lymphocytes make antibodies?
B cells
What type of hypersensitivity causes allergies?
Type I (immediate) hypersensitivity
What do lymphatic trunks drain into?
Lymphatic collecting ducts
What prevents lymph backflow?
One-way semilunar valves
What are interferons?
Proteins that block viruses and slow tumor growth
What are the 5 classes of antibodies?
IgG, IgA, IgM, IgD, IgE
What causes autoimmune diseases?
Immune system attacks its own cells
What are the two main lymphatic ducts?
Thoracic duct & Right lymphatic duct
What is edema, and when might it occur?
Swelling caused by blocked lymph drainage (like after node removal)
How does fever help the body?
Slows bacteria and boosts phagocytosis
What are 3 ways antibodies attack antigens?
Agglutination, precipitation, and neutralization
Why use immunosuppressive drugs after a transplant?
To prevent organ rejection
Which lymphatic organ is largest and what are its two tissue types?
Spleen; white pulp (lymphocytes) & red pulp (RBCs/macrophages)
What type of cells in lymph nodes fight infection?
Lymphocytes and macrophages
What are the two adaptive immune responses?
Cellular (T cells) and Humoral (B cells/antibodies)
What’s the difference between primary and secondary immune responses?
Primary = first exposure, slower; Secondary = memory response, faster
How does HIV harm the immune system?
It destroys helper T cells, weakening immunity