The Lymphatic System & Immune System Flashcards
What is the structure of the lymphatic system?
- lymph
- lymphatic capillaries
- lymphatic vessels, trunks and ducts
- lymph nodes (glands)
- lymphatic organs
- lymphatic nodule
Where are lymphatic nodules found?
- GI tract
- respiratory airways
- urinary tract
- reproductive tract
- tonsils
- Peyer’s patches )in the ileum of small intestine)
- appendix
Lymphatic nodules
= mucosa-associated lymphoid tissue strategically positioned to protect the body from pathogens (inhaled, digested or entered vis external openings).
Where is the thymus gland, and what is its purpose?
- located in mediastinum behind the sternum and lungs
- produces thymosin hormone for development of T cells
Lymph nodes (glands)
= filters the lymph before it returns to the bloodstream; also produce lymphocytes for immune response
Lymphatic vessels, trunks and ducts
= carry lymph from lymphatic capillaries through a number of lymph nodes and into large vessels (called trunks and ducts)
Lymphatic capillaries
= close-ended vessels with larger diameter than blood vessels that permits fluid into them but not out of them (found throughout body except CNS, splenic pulp and bone marrows).
Where is the spleen, and what is its purpose?
- located in abdomen behind the left part of the stomach
- doesn’t filter the lymph, instead it filters and stores platelets and blood as well as lymphocytes
- largest single mass lymphatic tissue
Lymph
= clear water derived from interstitial fluid, which contains proteins, lipid, foreign particles (bacteria) and cell debris from damaged tissues and lymphocytes.
What is the (4) functions of the lymphatic system?
- drains interstitial fluid
- transportation of dietary lipids
- protection against invasion
- transports clear, straw-coloured fluid from interstitial spaces surrounding to the blood
What are the lymphoid structures in humans?
- thymus
- spleen
- red bone marrow
- cervical lymph nodes
- auxiliary lymph nodes
- inguinal lymph nodes
- Peyer’s patches
What are common pathologies of the lymphatic and immune system
- Chronic fever of unknown origin
- Recurring fever with night sweats and weight loss
- Anaphylaxis – severe allergic reactions
Antibody-mediated (humoral) immune response (AMI)
= antibodies bind to antigens and inactivate them e.g.; B cells develop into plasma cells which secrete antibodies which binds onto antigen and destroys it.
Common response to body fluids and pathogens such as bacteria that have multiplied in body fluids.
Cell-mediated (cellular) immune response (CMI)
= ’cells attack cells’ e.g., CD8+ T cells reproduce into killer cells which leave lymphatic tissues to seek out and destroy antigens (fungi, parasites, viruses and some cancer cells).
What are the 2 types of immune response?
- cell-mediated (cellular) immune response (CMI)
- antibody-mediated (humoral) immune response (AMI)
What are the 2 types of T cells?
CD4+ cells
CD8+ cells
T cells
= develop in red bone marrow and migrate to thymus glands to mature; T cells develop antigen receptors
B cells
= matures in red bone marrow; develop into plasma cells and secretes antibodies
What are the 2 types of lymphocytes?
- B cells
- T cells
Fever
= abnormally high body temperature caused by toxins released by microbes. Increase in temperature intensifies the effects of body’s own antimicrobial substances, inhibits microbial growth and increases the growth of tissue repair