BIOLOGY
1.0 Blood composition
A connective tissue that transports substances (nutrients and waste) defence,
regulates body temperature and prevents haemorrhage.
Blood cells and platelets are produced in the red bone marrow a tissue from inside
some bones.
• 55% Plasma: Yellowish liquid, 91% of water where substances such as proteins,
antibodies, hormones, ions, and gases are dissolved.
• 41% Red blood cells: Contain haemoglobin (a red-coloured protein that transports
oxygen). Don’t have a nucleus
• 4% White blood cells: Provide defence against pathogens or foreign substances.
There are several types of these, all have a nucleus.
• Platelets: They coagulate the blood to control bleeding. They are cell fragments.
2.0 Heart Anatomy
Surrounded by the pericardium (a double membrane)
2.1 Cardiac cycle
• 1 Systole: Atria contracts and blood is
pushed into the ventricles through the opened
atrioventricular valves.
• 2 Systole: Ventricles contract and blood is
pumped to the arteries. Atrioventricular valves
close.
• 3 Diastole: Cardiac muscle relax. Pulmonary
, and aortic valves close. Blood enters to atria.
3.0 Blood vessels
• Arteries: Carry blood from the heart to the rest of the organs. Are elastic and
strong, they have a thick layer of muscular tissue because blood circulates at
high pressure. Branch into arterioles.
• Arterioles: They form networks and they have thin walls so they can make
exchange with cells. They are connected to venules.
• Venules: They are joined to the veins.
• Veins: Carry blood back to the heart. Have thin walls because blood circulates at
low pressure. Have valves that prevent the blood from flowing backwards.
3.0 Blood circulation
The right side sends deoxygenated blood to the lungs where becomes oxygenated
and returns to the left side of the heart to be sent to the rest of the body.
EXCRETORY SYSTEM
1.0 Excretory system
Excretion: Process in which the body expels the waste.
Organs that are involved in this process:
• Kidneys: Form urine which contains urea, water, mineral salts and more waste
• Lungs: Remove Co2 from the blood
• Sweat glands: Produce sweat
• Liver: Cleans the blood and produces urea.
2.0 Urinary System Anatomy
Urinary system manufactures, stores and eliminates urine.
• Renal pelvis: Connects with the
ureter
• Ureters: Two ducts that collect
the urine. Connects kidneys with
the bladder.
• Bladder: Stores urine.
1.0 Blood composition
A connective tissue that transports substances (nutrients and waste) defence,
regulates body temperature and prevents haemorrhage.
Blood cells and platelets are produced in the red bone marrow a tissue from inside
some bones.
• 55% Plasma: Yellowish liquid, 91% of water where substances such as proteins,
antibodies, hormones, ions, and gases are dissolved.
• 41% Red blood cells: Contain haemoglobin (a red-coloured protein that transports
oxygen). Don’t have a nucleus
• 4% White blood cells: Provide defence against pathogens or foreign substances.
There are several types of these, all have a nucleus.
• Platelets: They coagulate the blood to control bleeding. They are cell fragments.
2.0 Heart Anatomy
Surrounded by the pericardium (a double membrane)
2.1 Cardiac cycle
• 1 Systole: Atria contracts and blood is
pushed into the ventricles through the opened
atrioventricular valves.
• 2 Systole: Ventricles contract and blood is
pumped to the arteries. Atrioventricular valves
close.
• 3 Diastole: Cardiac muscle relax. Pulmonary
, and aortic valves close. Blood enters to atria.
3.0 Blood vessels
• Arteries: Carry blood from the heart to the rest of the organs. Are elastic and
strong, they have a thick layer of muscular tissue because blood circulates at
high pressure. Branch into arterioles.
• Arterioles: They form networks and they have thin walls so they can make
exchange with cells. They are connected to venules.
• Venules: They are joined to the veins.
• Veins: Carry blood back to the heart. Have thin walls because blood circulates at
low pressure. Have valves that prevent the blood from flowing backwards.
3.0 Blood circulation
The right side sends deoxygenated blood to the lungs where becomes oxygenated
and returns to the left side of the heart to be sent to the rest of the body.
EXCRETORY SYSTEM
1.0 Excretory system
Excretion: Process in which the body expels the waste.
Organs that are involved in this process:
• Kidneys: Form urine which contains urea, water, mineral salts and more waste
• Lungs: Remove Co2 from the blood
• Sweat glands: Produce sweat
• Liver: Cleans the blood and produces urea.
2.0 Urinary System Anatomy
Urinary system manufactures, stores and eliminates urine.
• Renal pelvis: Connects with the
ureter
• Ureters: Two ducts that collect
the urine. Connects kidneys with
the bladder.
• Bladder: Stores urine.
