The circulatory system
transports substances around your body. consists of your heart, blood vessels and blood.
Blood is pumped to your lungs so carbon dioxide can be exchanged for oxygen:
OXYGENATED BLOOD provides glucose and oxygen to cells
DEOXYGENATED BLOOD takes away waste products
blood passes through your heart TWICE
1. carries blood from heart to lungs and then BACK to your heart.
2. carries blood from your heart to all the other organs and then BACK to your heart.
right side of your heart: pumps blood that is low in oxygen to your lungs to pick up oxygen
left side of your heart: pumps blood that is rich in oxygen to all other parts of your body
the heart: responsible for continuously pumping blood around your body and so much of it's wall is muscle tissue.
The 4 chambers and dealing with problems in the he
left and right ATRIA (where blood enters)
left and right VENTRICLES (the atria contracts and forces blood into the ventricles)
The ventricles then contract and force blood out of the heart. VALVES prevent back flow of blood.
promblems in the heart:
- leaking heart valves can be replaced by donor or mechanical valves.
- Artificial pacemakers can be fitted if there is an irregular heart beat affecting the circulation
- Risk of infection, size of components and power supply are problems surrounding mechanical and electrical heart components.
ARTERIES (AWAY FROM THE HEART)
- Take blood from your heart to your organs
- Have thick walls made from muscle and elastic fibres
VEINS (GO TO THE HEART)
- Take blood from your organs to your heart.
- Have thinner walls and valves to prevent backflow
- Allow substances needed by the cells tro pass out of the blood.
- Allow substances produced by the cells to pass into the blood.
- Are narrow, thin-walled blood vessels.
If arteries begin to narrow and restrict the flow of blood, small mesh tubes called STENTS are inserted by surgeons to keep them open.
blood is a tissue with 4 components:
PLASMA: a staw coloured liquid that transports..
- carbon dioxed from the organs to your lungs
- the soluble products of digestion (glucose) from the small intestine to your organs
- Other waste products (urea) from your liver to your kidneys
RED BLOOD CELLS:
- transport oxygen from your lungs to the organs
- don't have a nucleus
- are packed full of the red pigment haemoglobin
- are small fragments of cells
- don't have a nucleus
- help blood to clot if you have a wound
The Blood (extended)
WHITE BLOOD CELLS:
- have a nucleus
- are suspended in the plasma
- form part of your body's defence system against pathogens
IN OTHER ORGANS: oxyhaemoglobin --> haemoglobin + oxygen
IN THE LUNGS: haemoglobin + oxygen --> oxyhaemoglobin
artificial blood is being developed as an alternative to blood transfusions. It carries oxygen in situations where a person's red blood cells do not function properly.
Transport systems in plants
Flowering plants have separate transport systems: XYLEM and PHLOEM
XYLEM tissue transports water and mineral ions from the roots to the stem and leaves. The movement of water from the roots through the xylem and out of leaves is called TRANSPIRATION STREAM.
PHLOEM tissue carries dissolved sugars from the leaves to the rest of the plant, including the growing regions and the storage organs.