B4 Organising Animals And Plants Flashcards
(39 cards)
Functions of blood?
They protect the body from pathogens.
Carry oxygen to build cells through the red blood cells.
Carries carbon dioxide away from the bodies cells.
Carries nutrients to the cells for function and growth.
Carries the waste product urea to be excreted by the kidneys.
What does blood contain?
Mainly:
55% plasma
1% white blood cells and platelets
45% red blood cells
What is plasma?
It is a yellow liquid that transports all your blood cells and other substances round the body.
Carries carbon dioxide waste to the lungs.
Urea from the liver is taken to the kidneys by plasma.
Small soluble products of digestion pass into the plasma from the small intestines.
What does plasma contain?
Water, urea, carbon dioxide, glucose
Not oxygen as it is carried by oxygen not plasma
What are red blood cells?
Are biconcave discs that have an increase in surface area to volume ratio for diffusion.
Have a red pigment called haemoglobin.
Have no nucleus making space for haemoglobin.
What are white blood cells?
They are bigger than red blood cells but a lot less of them.
They have a nucleus and form part of the body’s defence system.
Can form antibodies against microorganisms and some form antibodies against poison. Other white blood cells engulf and digest invading bacteria and viruses.
What are platelets?
Small fragments of cells and have no nucleus.
Gets the blood to clot at a wound and stops you bleeding to death or bringing in bacteria into the body.
What are arteries?
They carry blood away from the heart to the organs of your body.
Stretch to get the blood through them and back into shape after.
Have thick walls to withstand the pressure from the heart and blood.
Dangerous if an artery is cut as a lot of blood would come out.
What is a vein?
Carries blood away from the organs towards your heart.
Have thinner walls as not as much pressure. Heart valves are to prevent back flow of blood.
The valves open as the blood flows through them towards the heart.
The valves close of the blood flow backwards and squeezed back towards the heart.
What are capillaries?
Form a large network of tiny vessels linking the arteries and the veins.
Have very thin walls so substances like oxygen and glucose diffuse easily out of your blood into the cells.
Substances produced by cells pass easily into the blood though capillaries.
What happens to blood in the heart?
The blood that enters the top chamber of your heart called the atria.
Blood in your right atrium is deoxygenated blood from the body.
Blood coming into the left atrium in the pulmonary vein is oxygenated blood from the lungs.
The atria contracts together and forces blood down the ventricles.
Where does the blood go from the right ventricle?
Right ventricle»» deoxygenated blood»»> pulmonary artery»» lungs
Where does the blood go from the left ventricle?
Left ventricle»» oxygenated blood»_space;»> artery called the aorta»» round the body
Why is the left ventricle thicker than the right?
It gives the left the pressure needed to force the blood through the arterial system.
What do coronary arteries do?
Supply oxygenated blood to the heart by branching off the aorta and surrounding the heart.
What do stents do?
When there is fatty materials building up in the arteries blood flow becomes restricted so stents are inserted into arteries and helps keep them opens so blood can pass through them to the heart.
They have a metal mesh that is placed in the artery and inflated to open the vessel and move the fatty materials.
What does statin do?
This reduces blood cholesterol levels and slows down the rate of reaction of fatty materials being deposited in the coronary arteries. This reduces strokes and heart attacks from occurring as much.
What are biological and mechanical valves?
Mechanical valves are made of materials such as titanium. These last a long time but should take medication to stop blood clots around them
Biological valves are valves taken from animals and put inside to replace faulty or leaky valves. They don’t need medication but usually only work for 12-15 years.
What are artificial pacemakers?
This is an electronic device that corrects any irregularities in the heart rate. They are very light and are attached to two wires to the heart. The wires send electrical signals to the heart to make the heart work correctly.
What is an artificial heart?
These temporary hearts support your heart until replaced. This heart gives people a chance to have a relatively normal life but may have to stay in hospital for a while. The artificial heart can give a diseased heart a rest to recover. It removes the strain of keeping the blood circulating for a few weeks.
Process of breathing in:
Ribs move up and out and the diaphragm flattens, the volume of the chest increases.
Increased volume means lower pressure in the chest.
Atmospheric air is at a higher pressure than the chest so air is brought into the lungs.
Process of breathing out:
Ribs fall and diaphragm moves up, the volume of the chest gets smaller.
A decreased volume means increased pressure in the chest.
The pressure is higher in the chest so air is forced out of the lungs.
Adaptations of the gas exchange:
Increased surface area in the alveoli- this makes the most effective diffusion of oxygen and CO2.
Thin walls in the cell walls- they are one cell thick and allows diffusion to take place over the shortest distance.
Increase blood supply in the capillaries- maintains a concentration gradient in both directions.
Moist- easier for gas to dissolve.
What is the epidermal tissue?
This covers the surfaces to protect the plant. Stops infection and is waxy so waterproofs the leaf.
