transport systems in animals. providing for the cell’s needs the cell theory states that all...
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Transport systems in animals
Providing for the cell’s needs
The cell theory states that all living organisms are made up of cells or substances produced by cells.
All cells need nutrients eg glucose and oxygen in order to function properly, be active and grow.
The cells use the nutrients and produce wastes eg carbon dioxide that must be removed as they can be toxic and damage the cells.
The process that provides energy for the activity of cells is cellular respiration. The formula for cellular respiration is:
glucose + oxygen carbon dioxide + water + ENERGYC6H12O6 + O2 CO2 + H2O + Energy (ATP + waste heat)
Why we need organ systemsOrganisms which are single-celled or very
small and thin (less than 1 mm) can exchange materials through their body surfaces.
Because most multi-cellular organisms are too large for exchange of nutrients and wastes to occur through their body surfaces, they need organs to allow this exchange. Most multi-cellular organisms have organs arranged in systems to do this:
• A transport system - called the circulatory system to bring these nutrients to the cells, and to carry away wastes,
• A system to allow exchange of oxygen and carbon dioxide - called the respiratory system
• A system to obtain nutrients - called the digestive system
• A system to deal with and remove wastes from the body - called the excretory system
Open circulatory systems
• Open systems have one or more pumps (hearts) and tubes that empty into body cavities. The fluid (haemolymph) can leave the vessels.
• Found in smaller invertebrates
Mollusc
Insect
Crustacean
Closed circulatory systems
• Closed systems have one or more hearts and blood vessels that feed back to the heart. The fluid (blood) does not leave the vessels.
• Found mainly in the vertebrates• The number of chambers in the heart varies
The circulatory system carries blood and dissolved
substances to and from different places in the body. The Heart has the job of pumping these things around
the body. The Heart pumps blood and substances around
the
body in tubes called blood vessels. The Heart and blood vessels together make up the
Circulatory System.
What is a closed circulatory system?
The Mammalian Heart
Left Ventricle
Left AtriumRight Atrium
Right Ventricle
Right atrioventricular valve (tricuspid)
Pulmonary artery - Vein from Lungs
Aorta - Artery to Head and Body
Pulmonary artery - Artery to Lungs
Superior vena cava - Vein from Head and Body
Semi lunar valves
Left atrioventricular valve (bicuspid)
Blood flows out of and away from the ventricular chambers via arteries Arteries branch into arterioles
Arterioles branch into capillariesGas exchange occurs across capillaries, whose walls are one cell thick
Capillaries connect to venules Venules connect to veinsVeins return blood to the heart
Mammalian circulation