Structure + Function Of Blood Flashcards
Describe the structure of blood?
Consists of:
Plasma (fluid)
Cells=> red cells, white cells, platelets
What is another name for red blood cells?
Erythrocytes
Describe the structure of red blood cells?
Biconcave discs which gives larger surface area for exchange of oxygen + helps with flexibility when they go through capillaries
No nucleus + don’t contain DNA, RNA or mitochondria
Metabolically active despite no mitochondria
What is another name for white blood cells?
Leukocytes
What are 2 most common types of white blood cells?
Neutrophils
Lymphocytes
Describe the structure of neutrophil?
Polymorphonuclear=> irregular, multi-lobed nucleus
Granulocyte=> prominent cytoplasmic granules
What are 2 other types of granulocytes?
Eosinophil
Basophil
Describe the structure of mononuclear cells?
Single round nucleus
Lacks granules
Large, regular nuclei
What are 2 types of mononuclear cells?
Monocytes (largest type of WBC)
Lymphocytes
What is another name for platelets?
Thrombocytes
Describe the structure of platelets?
Clotting cells Cytoplasmic fragments No nucleus Membrane bound Contain granules
Where do blood cells come from?
Mature blood cells are produced from stem cells in bone marrow
What is plasma?
Fluid containing: Water Salts Proteins Organic molecules e.g.metabolites, carbohydrates + lipids
What are ionic constituents of plasma?
Positive ions (cations) e.g. sodium, potassium,calcium, magnesium + hydrogen ions Negative ions (anions) e.g. chloride, bicarbonate, phosphate, sulphate + organic anions
What is difference between plasma and serum?
Plasma= fluid component of whole blood Serum= fluid left after blood clotting
What are functions of blood?
Transport
Defence
Homeostasis
What is function of erythrocytes?
Transport oxygen from lungs to body tissues
Help in removal of CO2 from body tissues to lungs
Most CO2 carried as bicarbonate in plasma
Major constituents is protein Hb
Hb binds oxygen
Carries it from lungs to tissues
Describe the structure of haemoglobin?
Is protein tetramer made up of 4 polypeptide chains- 2 alpha globin chains and 2 beta globin chains
Each globin chain carries a haem molecule
Oxygen binds reversibly to iron atom by coordination
Process by which haemoglobin carries oxygen is no oxidation but it’s oxygenation
Give an example of transport
Albumin acts as general purpose carrier
But many substances have specialised carrier e.g. thyroxine binding globulin, transferrin
Immune system is divided into
Innate immune system
Adaptive immune system
How is neutrophil involved in immunity?
Primary defence especially against bacteria + fungi
Phagocytose + kill bacteria + fungi
Main mediators of innate immunity
How is lymphocytes involved in immunity?
Main mediators of adaptive immunity
Produce antibodies
Kill virus infected cells
What do eosinophil do?
Kill parasites
Involved in allergic responses
What do basophils do?
Kill parasites
Involved in allergic responses
Involved in inflammation
What do monocytes (macrophages) do?
Phagocytosis of dead cells + pathogens
When there is inflammation or something is going on in body,monocytes leave blood + move to tissues. When they are in tissues, we call them macrophages
Digested products are shown to adaptive immune system
Monocytes talk to innate + adaptive immune system
What is plasma-immune defence?
Immunoglobulins = made by B lymphocytes and act as antibodies against pathogens
Complement proteins= kill bacteria and other pathogens and cooperate with immunoglobulin and WBC
What is role of platelets?
Major role is primary hameostasis
Recognise damage at blood vessel wall
Form a platelet plug
Prevent/stop bleeding
What is haemostasis plasma?
Fibrinogen is major plasma proteins
Converted to fibrin, forms blood clot
Clotting factor control process
Fibrin clot reinforces primary platelet plug
What is function of blood?
Homeostasis-keeping internal environment of body constant
Maintaining pH
Controlling distribution of water and solutes
Distributing heat
What is average life span of red blood cell?
~120 days
What is diameter and thickness of red blood cells?
Diameter ~8um
Thickness ~2um
Give examples of few common blood tests
Full Blood count Liver function tests Urea and electrolytes Blood glucose Lipid profile
