what does this represents?
TRANSCRIPT
What does this represents?
If edward can suck 1 litre of blood per minute, by how many min would all the blood be sucked?
• Why do we need a transport system?
• Contents and functions of blood• Blood groups• Structure of blood vessels• Structure and function of heart • How blood flow around our body? • Heart diseases
The need for a transport system
Wastes substances
Food and O2 Diffusion is
fast enough
The need for a transport system
The need for transport system
The need for a transport system
CarriesBlood
Carries lymph
55% - Plasma
<1% - WBC and platelets
45% - RBC
90% water
10% dissolved substances
Pale yellowish liquid that carries blood cells and dissolved substances.
10% dissolved substances consists…..• Soluble proteins
(fibrinogen, prothrombin, anitibodies)
• Food substances (glucose, amino acid, mineral salts)
• Hormones ( eg: insulin)
• Waste products (urea, uric acids)
• Dissolved mineral salts (Ca2+ , Na+ , K+, HCO3
- )
Red Blood cells (erythrocytes)
• Transport O2 from the lungs to all parts of the body
• Circular, biconcave disc(Increases Surface area: vol ratio to absorb O2)
• Nucleus absent (to contain more haemoglobin)
• Elastic and can become bell-shaped to move through blood capillaries.
• Contains Haemoglobin
Red Blood cells (erythrocytes)
Function of red blood cells [Pg 147]
• Haemoglobin – iron-containing protein that carries oxygen in RBC
Haemoglobin
In the lung, + oxygen
Oxy- Haemoglobin
Unstable complex
In actively respiring tissues - oxygen unloaded
**Reversible
Why people living in high altitudes have more RBC in their blood?
• Less O2 in the environment
• More RBC in their blood
• More Haemoglobin per unit of blood
• Binds to more oxygen
Red blood cells
Red blood cells are produced by bone marrow.
Life span of 3-4 mths.
• Destroyed in the spleen to release haemoglobin.
• Haemoglobin broken down in liver to produce iron and bile pigments.
Red blood cells
From this picture, what are the difference between RBC and WBC?
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White blood cells[pg 142]
• White blood cells helps the body to fight infections.
• Also known as leucocytes. • Larger, few in number as compared to rbc• Irregular, colourless, no haemoglobin• Have a nucleus. • Two types of WBC• Shape different
During infection …[xtra]
Harmful Toxins
During infection…[xtra]
•Infects healthy cells •Causes cells to break up
Bind
White blood cells(leucocytes) pg 142
•Produce antibodies
Lobed nucleus
•Ingesting and digesting foreign particles
Round nucleus
Granular cytoplasm
• Able to change shape and move out of the blood capillaries into spaces among tissue cells to fight infection.
~Wound~
pg149
• Engulf (cover) and ingest (eat) bacteria by phagocyotsis.
• Bacteria digested by enzymes in the phagocytes.
• Enzymes found in granular vesicles.
• Dead phagocytes + bacteria = Pus
Bacteria infection on you?
Swelling and pain
• Presence of bacteria/virus stimulates the lymphocytes to produce a chemical substance known as antibodies (Ab).
• **Substances that stimulate the lymphocytes to produce antibodies are known as antigen.
Effects of Ab on bacteria
• Ab neutralize harmful toxins.
• Ab attach to bacteria cell membrane, causing bacteria to rupture.
• Cause bacteria to clump together (agglutinate) for easy phagocyotsis.
Ab neutralizes harmful toxins
Ab attach to bacteria cell membrane, causing bacteria to rupture
bacteria bacteria
‘burst open’
Cause bacteria to clump together (agglutinate) for easy phagocyotsis
Bacterial clumps being phagocytosed.
• Antibodies attach to viruses, making them unable to bind to host cell.
Healthy human cell
Why do you get chicken pox only once in your lifetime?
• Ab produced are specific to the particular infection.
• Stay in the blood for along time.
• Immune to chicken pox.
Chicken Pox Virus
Why do doctors encourage breast feeding of babies?
• Milk contains high amount of antibodies which protects the baby from bacterial and viral infection.
During immunisation (pg 150)
•Dead bacteria and altered virus injected.
•induced (caused) the lymphocytes to produce antibodies specific to the virus/bacteria.
Why our body cant fight against HIV virus..…[XTRA]
Antigens of HIV virus
Organ transplant/tissue rejection[pg150]
?Unknown X
• Any organ from another person is treated as a foreign object by our body immune system.
• Our lymphocytes would produce antibodies to destroy the transplant organ.
Organ transplant/tissue rejection
• From our own tissues.
• Obtain organ transplant from genetically related individuals.
• Take immuosupressive drugs– Inhibit the production of antibodies by lymphocytes.
- lower resistance to infections- longtime
How to organ transplant/tissue rejection
Phagocytosis
Tissue/organ rejection
Ab production
• Not a cell
• Small membrane-bound fragments of cytoplasm from certain bone marrow cells.
• Involves in blood clotting during injury.
Platelets(thrombocytes)[pg143]
Blood clotting process
• http://www.footprints-science.co.uk/Bloodclotting.htm
Blood clotting[pg 148]
Damaged tissues and platelets
Thrombokinase (enzyme)
Fibrinogen(soluble protein)
Fibrin(insoluble protein)
Releases
Prothrombin (inactive enzyme)
Thrombin
(active enzyme)
Thrombokinase
Ca2+ ions
Thrombin
Blood clotting
Damaged tissues and platelets
Thrombokinase (enzyme)
Releases
Then through a series of enzyme catalysed reactions, fibrinogen is converted into fibrin .
Blood clot
• fibrin threads form a mesh, trapping red blood cells to form a blood clot.
•Prevent excessive loss of blood.
•Seal the wound, protecting it from infection.
• After clotting, serum is left behind. • Serum = plasma without clotting factors
• Heparin prevents blood from clotting in undamaged blood vessels.
• Thrombokinases neutralises the action of heparin.
Blood clot
• The inability of blood to clot is known as haemophilia.
• Due to the lack of clotting factors.
• Consequence: slight injury results uncontrolled bleeding.
Haemophilia
The royal disease
1819-1901
Summary of functions of blood
Blood
Transport function
Protective function
RBC O2
Plasma
WBC
Phagocytes
Platelets