Lymphatic System Flashcards
(30 cards)
1
Q
What does the lymphatic system consist of and what does it do
A
- Consists of fluid called lymph, lymphatic vessels that transport the lymph, and a number of structures and organs containing lymphatic tissue and red bone morrow, where stem cells develop into various types of blood cells. They then assist in defend the body against disease causing agents
2
Q
Functions of the lymphatic system
A
- Draining excess interstitial fluid and returning it to the blood
- Transporting Dietary lipids
- Carrying out the immune response,
- Maintains blood volume and pressure
3
Q
What are the primary lymphatic organs
A
- Red Bone Marrow
- Thymus
4
Q
What are the secondary lymphatic organs
A
- lymph nodes
- Spleen
- Lymphatic nodules
5
Q
Describe the flow of the lymph
A
- Lymph capillaries
- Lymphatic vessels
- Lymph Trunk
- Thoracic duct
- Subclavian veins
6
Q
How does the lymph move in the system
A
- Skeletal muscle contractions and respiratory movement
- Valves in the lymphatic vessels also aid the flow of lymph and stop the back flow
- When Pressure in the interstitial fluid is greater then the lymphatic capillaries it opens and lets in the lymph, when the pressure in the capillaries the cells adhere more and close the gap, the pressure is relived as the lymph moves further into the capillaries.
7
Q
Explain what Lymph nodes are and do
A
- They filter and trap antigens which are then destroyed by macrophages and lymphocytes
- Enlarge in response to inflammation/infection, this is due to a influx of other lymphocytes
8
Q
Where are lymph nodes in the body
A
- Lymph nodes are located throughout the body but the largest groupings are found in the neck, armpits, and groin areas.
9
Q
What is the spleen and what does it do
A
- Haemolyses old and damaged erythrocytes.
- Stores blood, B Cells, T Cells
- Can produce additional erythrocytes when required
10
Q
What is the Thymus and its job
A
- Lies between the sternum and the large blood vessels
- Its where T cells are manufactured
11
Q
What are the bodies primary defences, physical and chemical
A
Physical Barriers
- Epidermis
- Mucosa
- Mucus
- Hairs-cilla
- Lactermal Apparatus - Crying
- Saliva
- Urine
- D+v
Chemical
- Sebum, Slightly acidic film on the skin
- Lysozyme, Substance in sweat, saliva
- Gastric Juice
- Vaginal Secretions
12
Q
What are the bodies secondary defences
A
- Antimicrobial proteins
Interferons
Compliment
Transferrins - Natural Killer Cells
Phagocytes - Inflammation
- Fever
13
Q
What are the 5 stages of Phagocytosis
A
- Chemotaxis , movement of phagocyte to site of damage
- Adherence, Binding to the foreign microbe of substance
- Ingestion, Plasma membrane engulfs the micro-organism with a sac called phagosome
- Digestion - The phagosome enters the cytoplasome and digests the microbe with enzymes
- Killing.
14
Q
What is the job of Interferons
A
- They protect uninfected host cells from viral infection, they do this by creating a antiviral protein which interfere with viral replication
15
Q
What does the Compliment system do
A
- It activates usually inactive plasma proteins to ‘compliment’ or enhance the immune system, it promotes phagocytes and contributes to inflammation
16
Q
What is the job of the Interferons
A
- Inhibit certain bacteria growth by reducing iron levels
17
Q
Define the Natural Killer Cells
A
- They will attack any cell displaying any unusual or abnormal plasma membranes, they release granules which are toxic
18
Q
Define Phagocytes
A
- They are specialised cells that perform Phagocytosis which is the ingestion of microbes, the two main types of these are Neutrophils and Macrophages
- In response to infection Neutrophilles and Monocytes turn into wandering Macrophages. Fixed macrophages stand guard in specific tissues like liver
- Dead phagocytes tuen into pus
19
Q
Define Neutrophils
A
- Engulf and digest microbes/antigens with lysozyme, they then release chemotaxis that attract more neutrophils and macrophages to the area
- 1st on scene and attract macrophages
20
Q
What do Macrophages do
A
- Attract T and B cells to the area of injury
- 2nd on scene
21
Q
Define and explain the job that Inflammation has in the bodies response to injury
A
- Its a nonspecific defence response that the body has to tissue damage, pathogens, abrasions, chemical irritations and extreme temperature
- Inflammation is a attempt to dispose of microbes, toxins, or foreign material at the site of injury to prevent the spread to other tissues, and to also prepare the site for tissue repair in a response to restore tissue homeostasis.
22
Q
Four characteristics of Inflammation are
A
- Redness
- Pain
- Heat
- Swelling
- Loss of function
23
Q
What are the three basic response to inflammation
A
- Vasodilation and increased permeability of the blood vessels
- Emigration of phagocytes from the blood to the interstitial fluid
- Tissue repair (clotting cascade)
24
Q
Explain why vasodilation and increase in permibilty of the blood vessels helps
A
- Increase in permeability means that substances that are normally retained in the blood are permitted to pass through to the site of injury, thus allowing defence proteins such as antibodies and clotting factors to enter the injured area.
- Vasodilation increases the blood flow to the area which also helps with the removal of microbes toxins and dead cells
25
What are the other aspects to the inflammatory response and what does each one do
- Histamine, Released by mast cells, basophils and platelets, neutrophils and macrophages attracted to the site of injury also release histamine and it causes vasodilation and increased permeability of the vessels
- Kinins, Induce vasodilation and increased permeability of vessels, can also cause bronchoconstriction
- Prostaglandins, are lipids which when released by the E series intensify the effects of histamine, can also stimulate emigration of phagocytes
- Leukotrienes, produced by basophils and mast cells they cause increased permeability and attract phagocytes and adhere them to pathogens
- Compliment - Stimulate histamine release and attract neutrophils by chemotaxis, can also destroy bacteria
26
What does Histamine bind with
- H1 receptors in the smooth muscle to dilate blood vessels and increase permeability, causes bronchospasm (which is why a wheeze is present in anaphalatic shock)
27
What are B- cells
| adaptive Immunity
- Produced in bone marrow
- Produce lg antibody which then bind to antigens and clump together to be eaten by microbes
- Inactive B cell attaches a microbe
- B cell recognises antigen and differation occurs
- Plasma cells and Memory cells are the outcome
- Plasma cells secrete hundreds of millions of antibodies for unto 4-5days after exposer until the plasma cell dies
- Memory cells are ready to respond more rapidly and forcefully should the same happen again
- Plasma cells can only secrete one type of antibody to the antigen receptor.
28
What are T-Cells
| adaptive immunity
- Produced in the thymus
- They are Helper T-cells, Killer T-cells, Suppressor T-cells
- In antibody mediated response B cells transform into plasma cells which secrete immunoglobins
29
Define Mast Cells and what they do
- Mast cells are located in connective tissue, including the skin, the linings of the stomach and intestine, and other sites. They play an important role in helping defend these tissues from disease. By releasing chemical "alarms" such as histamine and heparin, mast cells attract other key players of the immune defense system to areas of the body where they are needed.
30
What is the difference between a Pathogen and Antigen
- Antigen is a molecule capable of causing the immune system to produce antibodies against it. It may be foreign or formed inside the body. Antigens are usually polysaccharides , lipids or peptides e.g. hemagglutinin ( found in Influenza virus ) .
- Pathogen is an infectious agent that may cause a disease. Virus, bacteria, fungus and other microorganisms are often pathogenic,
