B4.1))) The Blood Flashcards
What are the components of the blood?
Plasma, red blood cells, white blood cells and platelets.
What does the blood do?
It carries many dissolved substances around body.
What does the blood plasma do?
Transports all of the blood cells + some other substances around body.
Waste carbon dioxide produced by cells carried to lungs.
Urea formed in liver from breakdown of excess proteins carried to kidneys where removed from blood forming urine.
Small soluble products of digestion pass into plasma from small intestine and transported to individual cells.
What facts are there about red blood cells?
Biconcave discs: gives increased surface area to volume ratio.
Haemoglobin: red pigment binds to oxygen.
No nucleus: more space for haemoglobin.
What facts about white blood cells?
Bigger than red blood cells.
Fewer white blood cells.
Have nucleus.
Part of body’s defence system.
Some white blood cell (lymphocytes) form antibodies against harmful microorganisms.
Some form antitoxins against poisons made by microorganisms.
Others (phagocytes) engulf and digest invading bacteria + viruses.
What facts are there about platelets?
Fragments of cells.
No nucleus.
Important for helping blood clot at site of a wound.
Blood clotting series of enzyme-controlled reactions result in converting fibrinogen into fibrin. Produces network of protein fibres capture lots of red blood cells + more platelets form jelly-like clot stops bleeding to death. Clot dries and hardens to form a scab. Protects new skin as grows stops bacteria entering body through wound.
