Lymphatic System Flashcards
What are the organs of the lymphatic system?
- Spleen
- Thymus
- Lymph Vessels
- Lymph Nodes
- Tonsils
What are functions of the lymphatic system?
Produce, maintain and distribute lymphocytes and lymphoid cells that provide defence against infection and foreign substances
What are components of the lymphatic system?
- Lymph
- Lymphatic vessels
- Lymphoid cells
- Lymphoid tissues
Describe lymph
Fluid that resembles plasma
Describe lymphatic vessels
Begin in peripheral tissues, connected to veins
What are examples of lymphoid cells?
Lymphocytes and phagocytes
Describe lymphoid tissues in primary and secondary responses
Primary
-Sites where lymphocytes form and mature
Secondary
-Sites where lymphocytes are activated
Describe circulation of fluid in the lymphatic system
-Lymphatic vessels carry lymph from peripheral tissues to venous system
Peripheral Tissues —> Lymphatic Capillaries –> Lymphatic Vessels/Ducts —> Subclavian vein
What are lymphocytes?
Responds to abnormal body cells, eliminate threat through physical & chemical attack
What are phagocytes?
Cells that perform phagocytosis
Describe role of immunity the the lymphatic system
Ability to resist infection and disease
What is an antigen?
Substance capable of inducing an immune response (bacteria, foreign object)
What is a pathogen?
A disease causing organism
What is phagocytosis?
“Cell eating”: engulfing cellular debris or foreign material
What is an antibody?
A protein produced by plasma cells that binds to specific antigen and promotes destruction and removal from body
What are the general innate (non-specific) immunity defences?
- First line of defence: physical barriers
- Phagocytes
- Immune surveillance
- Interferon
- Inflammation
- Complement system
- Fever
Describe the role of a physical barrier
- Slow entry of infections into body
- Internal defence processes attack infectious organisms if they enter
- Keep hazardous organisms outside
Describe the role of immune surveillance
- Continuous policing of peripheral tissues by natural killer cells
- Destroys cells that has antigen, including own abnormal cells
Describe the role of interferons
Small proteins released by activated lymphocytes and macrophages
Describe the role of inflammation
- Localised tissue response to injury
- Prevent additional pathogens from entering wound
- Slow spread of pathogens from injury sites
Describe the complement system
Complement proteins kill pathogens, enhance phagocytes and inflammation
What is a fever?
Moderate increase in body temperature
What is adaptive (specific) immunity?
Involve T and B cells that responds to specific antigen
What are cytotoxic T-cells?
Attack foreign cells attacked by viruses
