lymphatic & immune systems. lymphatic pathways & capillaries
TRANSCRIPT
Edema24 liters of lymph are pushed from capillaries every day to bathe the cells – if it isn’t all collected – it’s edema!!
Post-mastectomy lymphedema ------>
What is lymph?
• It is plasma• It is interstitial fluid• It is fluid picked up by lymph capillaries• It depends where it is!!
What does lymph do?
• Collects fluid and proteins that squeeze out through the capillaries
• Absorbs dietary fats• Transports bacteria and
viruses to lymph nodes
Keep it moving
• No heart• Skeletal muscle movement• Valves prevent backflow• Trunks contract a little• Inhaling creates pressure that moves lymph
from abdominal to thoracic cavity
Lymph nodes
• Bean shaped • 2.5 cm long• Medulla has T cells and
macrophages• One exit slows traffic
Lymphoid organs
• Do NOT filter lymph, but play a role– Tonsils (MALT)– Peyer’s patches (MALT)– Thymus gland– Spleen
MALT = mucosa-associated lymphatic tissue
Spleen & Thymus
• Spleen – filters blood– White pulp contains
lymphocytes– Red pulp filters out
broken down RBC’s
• Thymus – contains lymphocytes that mature in T lymphocytes
2 Lines of Defense• Innate
– Species resistance– Mechanical barriers– Chemical barriers
• Tears• Stomach acid• Salt• Antimicrobials
– Fever– Natural Killer Cells– Inflammation– Phagocytosis
• Adaptive– Antingens (sprinkles)– Antigen-presenting cells– T cells – Cytotoxic T cells (fight cancer)– Memory T cells– Helper T cells (stimulate B cells)– B cells
Immunoglobins = antibodies
What’s the diff?
T cells• Directly attack cells w/ toxins or
growth inhibitor• Mature in the thymus gland• Activated by antigen-presenting
cells• Helper T cells are targeted by HIV• Cytotoxic T cells target tumors
and virus infected cells• Memory T cells confer immunity• Activate B cells
B cells• Differentiate into Plasma
cells that produce antibodies
• Activated by specific antigens or helper T cells
• Mature in the bone marrow• Part of the humoral
response
What do antibodies do?
• Attack– Disable them so that macrophages will get them
• Activate enzymes that attack antigens– Complement proteins
• Change the environment to stop the antigens– inflammation
Tissue Rejection
• Human Leukocyte Antigens (HLA’s) determine our tissue type
• Inherited from parents• Three groups: HLA-A,HLA-B and HLA-DR. • many different specific HLA proteins within each
of these three groups. • ¼ chance that you and a sibling are identical• http://www.stanford.edu/dept/HPS/transplant/
html/hla.html
Allergic (hypersensitivity) Reaction
• Type I (anaphylactic)– Triggered by allergens– Occurs within minutes– Overproduction of IgE
antibodies – Severe inflammation
Ex: peanut allergy
• Type IV (delayed-reaction)– Repeated exposures to
allergins– Activates T cells– T cells cause
inflammation
Ex: poison oak