56 Questions
What is the main constituent of plasma?
Water (90-92%)
List the three main functions of the globulins.
- Antibodies (immunoglobulins) for immunity 2. Transport of hormones and mineral salts 3. Inhibition of some proteolytic enzymes
What are the main components of blood?
Plasma and blood cells
What are the functions of blood?
Transporting oxygen, nutrients, hormones, heat, antibodies, clotting factors, and wastes
What is the normal percentage composition of plasma and blood cells in blood?
Plasma 55%, cell fraction 45%
How can blood cells and plasma be separated?
By centrifugation (spinning) or by simple gravity
What is the approximate percentage of body weight that blood makes up?
About 7%
How much blood is present in a 70 kg man?
About 5.6 litres
What is the main function of red blood cells?
Transport of gas, mainly oxygen, and some carbon dioxide
What is the lifespan of red blood cells in the circulation?
About 120 days
What is the process called when immature red blood cells are released into the bloodstream and mature into erythrocytes?
Erythropoiesis
What are the two vitamins required for red blood cell synthesis?
Vitamin B12 and folic acid
What is the average lifespan of vitamin B12 stores in the liver?
Several years
What is the oxygen-carrying capacity of an average red blood cell?
Over a billion oxygen molecules
What is the name of the iron-containing complex in the haemoglobin molecule?
Haem
What is the iron-carrying protein in the bloodstream?
Transferrin
What happens to the color of blood as its oxygen content increases?
It becomes bright red
What causes the dark bluish color of blood with lower oxygen levels?
It is not saturated with oxygen
What is the equation for the reversible binding of oxygen to haemoglobin?
Oxyhaemoglobin
What conditions can cause oxyhaemoglobin to release its oxygen readily?
Low pH
What is the hormone that regulates red blood cell production?
Erythropoietin
What is the primary stimulus for increased erythropoiesis?
Hypoxia
What is the lifespan of erythrocytes?
About 120 days
Where does the breakdown of erythrocytes take place?
Spleen, bone marrow, and liver
What is formed from the haem part of the haemoglobin during breakdown?
Biliverdin, which is almost completely reduced to bilirubin
What determines an individual's blood group?
Inherited antigens carried on the red blood cell membrane
Why is it important to match the blood types of the donor and recipient during transfusion?
To avoid an incompatible transfusion reaction
What percentage of the UK population has A-type antigens on their red cell surface?
About 55%
What antibodies do blood group A individuals make?
Anti-B
Why are blood group AB people sometimes known as universal recipients?
They make neither anti-A nor anti-B antibodies
Why is cross-matching required prior to transfusion?
To ensure there is no reaction between donor and recipient bloods
What is the effect of hypoxia on erythropoietin production?
It stimulates increased erythropoiesis
What percentage of people are Rhesus-positive (Rh+)?
85%
What type of blood can the AB group receive?
Compatible with all groups
What is the function of neutrophils in the body's defense system?
Protect the body against bacterial invasion, and remove dead cells and debris from damaged tissues.
What is the main role of eosinophils in the body?
Elimination of parasites, such as worms
What type of blood can the O group donate to?
Compatible with all groups
What is the main function of basophils in the body?
Promote inflammation and contain histamine
What are the two main types of leukocytes?
Granulocytes and agranulocytes
What type of blood can the B group receive?
Compatible with B and O
What do Rh- individuals have the capability of making?
Anti-Rhesus antibodies
What is the total percentage of leukocytes in the blood volume?
About 1%
What are the nuclei of granulocytes like?
Multilobed
What type of blood can the A group donate to?
Compatible with A and AB
What is the main function of mast cells?
Degranulate within seconds of binding an allergen
What is the main function of macrophages?
Actively phagocytic and produce cytokines
What are the two distinct types of lymphocytes?
T-lymphocytes and B-lymphocytes
What is the normal blood platelet count?
Between 200 x10^9/L and 350 x10^9/L
What is the main function of platelets in the body?
Promote blood clotting and haemostasis
What causes the rapid onset of allergic symptoms following exposure to an allergen?
Mast cells degranulating within seconds of binding an allergen
What hormone stimulates platelet production?
Thrombopoietin
What is the main function of monocytes?
Actively motile, phagocytic, and produce interleukin 1
Where do most lymphocytes reside in the body?
In tissues, including lymphatic tissue such as lymph nodes and the spleen
What is the main function of interleukin 1?
Stimulates the production of some globulins by the liver, enhances the production of activated T-lymphocytes
What is the main function of the hormone thrombopoietin?
Stimulates platelet production
What happens when platelets come into contact with a damaged blood vessel?
Their surface becomes sticky, they adhere to the damaged wall, and release serotonin and thromboxanes
Test your knowledge about the process of erythropoiesis and the release of oxygen from oxyhaemoglobin in low oxygen environments. This quiz covers the mechanisms involved in increasing oxygen release to tissues during hypoxia.
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