The Lymphatic System Flashcards
What is the lymphatic system
It is when the body fights these infections.
We have a system of vessels, organs and tissues that makes up the lymphatic system.
What are the types of line of defense?
Resistance
Resistance is the ability to fight a disease
What is susceptibility - first line of defence
- a lack of resistance
What are microorganisms (pathogens)
Viruses, bacteria, fungi and parasites
Viruses exist within cells which they destroy
Bacteria multiple in interstitial fluid
Parasites burrow through internal organs
What are the primary cells of the lymphatic system
Lymphocytes
Lymphatic tissue is everywhere
- They are smaller than monocytes
- 30% in white blood cells
- some in blood, some are in lymphoid tissue
- originate from stem cells in red bone marrow/lymphoid tissue
What are white blood cells
They are associated with defence and immunity
They destroy and detect foreign / abnormal material
They are the largest blood cells
They contain 1% of blood
What are the two main types of blood cells
Granulocytes
They contain internal granules which release specific enzymes/chemicals
Agranulocytes
- no granules
-monocytes, lymphocytes
What are the three different granulocytes
Neutrophils
- respond to bacteria and fungal
- use phagocytes
Basophils
- respond to allergies
- contain histamine (inflammatory) and heparin (anticoagulant0
Eosinphils
- Parasites: to big to be phagocytosed
- release toxic chemicals
What are monocytes and what do they develop into?
Monocytes are a type of white blood cell
- agranulocytes
- they are the largest
- some are in blood and some are in tissue where they develop into macrophages
- both produce interleukin
Interleukin increases body tempo through hypothalamus
- it stimulates liver to form globulins in liver (antibodies immunoglobulins)
- enhances production of t lymphocytes
Macrophages produces more important chemicals for inflammation and tissue repair.
- they use phagocytoses
What are b lymphocytes
- formed in bone marrow
- stored in lymphoid tissue
- produced antibodies (immunoglobulin) - proteins that attach to certain antigens
- so they only respond to one antigen
- they are part of the (humeral) mediated immunity
What are t lymphocytes
- matured in thymus
- programmed to only respond to one antigen
- found in circulation more
- rely on other cells to present the antigen to be destroyed
- part of thee cell - mediated immunity
Describe the structure of lymphatic system
- So we have vessels
- this is a network of lymphatics that begin in the peripheral tissue
- The vessels begin with lymphatic capillaries which are blind ended type vessels
- most lymphatics connect to the veins and follow Venus system - Then we have fluid
- the fluid is called lymph and it resembles blood plasma however it doesn’t have high concentrations of proteins and solute
- the lymph has high concentrations of lymphocytes (specialised cells that defend the body)
- the fluid goes into the interstitial spaces which then go into the the lymphatic capillaries
3.From the lymphatic capillaries lymph flows into larger lymphatic vessels that lead towards the trunk of the body- these have soles of epithelium that from valves
- So they are valves in lymphatic system to prevent back flow because it doesn’t have a big muscle layer so valances are needed to be present. Similar to veins - their network and their design - no pressure so the muscle contractibility is how the lymph moves through the body.
E.g swollen ankles because lymphatic system isnt working - Lymphatic vessels drain into two large collecting structures called lymphatic ducts
Describe the lymphatic ducts
The thoracic duct (largest)
- contains the cisterna chyli - large ballon - dilated vessel
- drains everything else
- this is the main collecting vessels in the lymphatic system.
- Drains into subclavian artery
The right lymphatic duct
- smaller than thoracic duct
- drains right head, right upper limb, chest.
- Lies in right side of neck root, drains into RIGHT subclavian artery
