blood groups/lymphatic system Flashcards
what are antigens
Proteins on the surface of RBCs
Identify what type of cell it is
Specific shape
what are antibodies
specialised proteins
Complimentary to non-self antigens
Combine to form antigen-antibody complex –> destroys antigen
which blood groups are referred to as universal donors and universal recipients
universal donor: O
universal recipient: AB
for blood group A, explain the antigens/antibodies presents and which groups it can donate to
antigen: A
antibody: B
donates to: A, AB
for blood group B, explain the antigens/antibodies presents and which groups it can donate to
antigen: B
antibody: A
donates to: B, AB
for blood group AB, explain the antigens/antibodies presents and which groups it can donate to
antigen: A and B
antibody: none
donates to: AB
for blood group O, explain the antigens/antibodies presents and which groups it can donate to
antigen: none
antibody: A and B
donates to: A, B, AB, O
explain what transfusions are
Transfer blood or blood components from one person to another
Must match ABO blood group otherwise erythrocytes causes agglutination and foreign cells will clump together and disintegrate
Rh blood groups must also be matched to prevent production of anti-Rh antibodies
Mismatch causes similar slumping to ABO incompatibility
list the different types of transfusions
whole blood
red cell concentrates
platelet concentrates
cryoprecipitate
immunoglobin
autologous tranfusions
explain what a whole blood transfusion is
Blood taken from the donor but with a chemical added to prevent clotting
Used in cases of sever blood loss
explain what a red cell concentrate transfusion is
The most widely produced component of blood
Produced by spinning blood in a centrifuge to separate components
Platelets and white blood cells may or may not be removed by the centrifuge
Used for patients suffering from heart disease of sever anaemia
explain what a platelet concentrate transfusion is
Given to patients who have a reduced number of abnormal platelets
explain what a cryoprecipitate concentrate transfusion is
Obtained by freezing plasma and letting it thaw slowly, leaving the cryoprecipitate as a solid
Contains many of the substances necessary for blood clotting
Used for severe bleeding or to treat some forms of haemophilia
explain what an immunoglobin transfusion is
Groups of proteins acting as antibodies and extracted from blood
Used to treat patients who are deficient in antibodies
Particular immunoglobins can treat people with no immunity to particular diseases
explain what a autologous transfusion is
A patients own blood is used, collected from the patient prior to an operation that may require a blood transfusion
Often used in elective surgery
Autologous transfusion eliminate risk of disease transmissions and possible side effects of usual transfusions
what is the lymphatic system
Part of the body’s internal defence against disease-causing organisms
Main function is to collect fluid that escapes walls of blood capillaries and return it to the circulatory system
- Fluids leak out the arterial at the end of capillaries due
to high pressure
- Some fluid is returned to the capillary in the venous
end, but the excess is returned to blood via the
lymphatic system
- The fluid returned is called a lymph
- Clear pale yellow colour
Explain the structure of the lymphatic system
A network of lymph capillaries joined to a larger lymph vessel
Lymph nodes, located along the length of some lymph vessels
Describe lymph vessels
Lymph doesn’t circulate – one way system
Lymph capillaries are slightly larger and more permeable than regular capillaries
Lymph vessels originate as blind-ended tubes in spaces between cells of tissues
Have valves and relatively low pressure
Network of lymph vessels join to form 2 lymphatic ducts that empty into large veins in the upper chest
Lymph is moved through lymphatic vessels as a result of smooth and skeletal muscle and valves
- Smooth and skeletal muscle contracts wand push
lymph along
- Large lymph vessels have valves that close when the
pressure drops, preventing backflow of lymph
Describe structure of lymph nodes
Also called lymph glands
Occur at intervals along lymphatic vessels
Most numerous in the neck, alimentary canal, armpits and groin
Bean shape, range from 1 – 25 mm in length
Each is surrounded by a capsule of connective tissue framework that extends into the node
Within the framework are masses of lymphoid tissue containing cells (lymphocytes/macrophages/plasma cells.)
Spaces between cells are criss-crossed by a network of fibres
Explain the process of lymph travelling lymph nodes
Lymph enters through the convex side of the node, filters through the spaces and passes out of vessels on the opposite side
Lymph passes through several nodes before entering blood
explain the role of the lymphatic system in defence against disease
Lymph entering lymph nodes contains cell debris, foreign particles and micro-organisms which may be able to cause disease and must be destroyed
Larger particles are trapped in the meshwork of fibre as lymph flows through spaces in the nodes
Large phagocytic cells called macrophages destroy these particles by phagocytosis and enzymes
Most bacteria ingested in this way is destroyed within 10 – 30 minutes
When infections occur, the formation of lymphocytes increases, causing lymph nodes to become swollen and sore
describe the other components of the lymphatic system
Spleen: acts as a large lymph node
Bone marrow: where lymphocytes are formed
Tonsils: catch harmful bacteria and produce lymphocytes to destroy them
Thymus: where lymphocytes develop and mature
