bio

Biology unit 2 - The heart

• Tissue = a group of the same type of specialised cell that work together
• muscle= a group of specialised tissue that work together
• organs = a group different tissues work together to carry out a specific function in the body

The heart

• Blood that comes form tissues is deoxygenated blood and it goes thorugh the heart to be pumped to the lungs where it will under go gas exchange
• then this blood would become oxygenated and will then return to the heart and is pumped by the heart to different body tissues and cells .

the heart - oxygenated blood

• Two sides of the heart are spilt into two by the septum
• 1) the vena cava brings blood from the body to the right atrium
• 2) when the atrium is full muscles called valves push the blood to the right ventricle .
• 3) when the ventricle is full , muscles in the wall contract and force blood to go though the pulmonary artery .
• 4) this blood is deoxygenated , so it is sent tot eh lungs to pick up oxygen via the haemoglobin in the blood
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the heart - oxgenated blood

• 
• then the oxygenated blood
• 1) goes through the left atrium
• 2) when full up goes to the left ventricle past valves
• 3) then the ventricle fills up and the muscles contract forcing blood to be pushed to the aorta
• 4) the aorta pushes the blood around the bdy to tissues and cells .