Chapter B4- Organising Animals And Plants Flashcards
What are the components of blood?
Plasma
Red blood cells
White blood cells
Platelets
What colour is blood plasma?
A yellow liquid
What does plasma do?
Transports all of your blood cells and some other substances around your body
Give an example of other substances plasma carries
Waste carbon dioxide is carried to the lungs
Urea formed in the liver is carried to your kidneys
What do red blood cells do?
Pick up oxygen from the air in your lungs and carry it to the cells where it is needed
Name an adaptation of red blood cells
They are biconcave discs for a larger surface area
They are packed with haemoglobin that binds to oxygen
They have no nucleus, making more space for haemoglobin
What do white blood cells do?
They are part of your bodies defence system against harmful microorganisms
What do platelets do?
Help the blood to clot if you are wounded- this means you will not bleed to death. It also protects you from harmful bacteria entering your body with a scab over the harmed area.
What are the three main types of blood vessels?
Arteries, veins and capillaries
What do arteries do?
Carry blood away from your heart to the organs around your body
What colour is the blood in arteries?
Bright red- oxygenated
What are the traits of an artery?
Arteries have thick walls containing muscles and elastic fibres
They stretch as the blood goes through them and go back into shape afterwards (pulse)
Why is it dangerous if an artery is cut?
As the arteries are under pressure, blood will squirt out each time your heart pumps which is a large problem as you will eventually die of blood loss
What do veins do?
The veins carry blood away from the organs towards your heart
What is the colour of the blood in veins?
Blue- deoxygenated
What are traits of a vein?
They have much thinner walls than arteries and often have valves to prevent the backflow of blood
What do valves do?
if blood tries to flow backwards due to the skeletal muscles then the valves close preventing backflow
What do capillaries do?
Capillaries link arteries and veins
What are the traits of capillaries?
Capillaries have thin walls and are very narrow
Why do capillaries have thin walls?
To enable substances such as oxygen to diffuse easily out of the blood and into your cells.
What is a double circulatory system?
One transport system carries blood to the heart, then lungs then back again
Another carries blood from your heart to the other organs of your body
What does your heart do?
Pump blood around the body
What are the walls of your heart made up of?
Muscle
Explain the process of the pumping of blood in the heart
Deoxygenated blood enters the right side of the heart through the veins cava, into the right atrium. The tricuspid valve pumps this through to the right ventricle. The pulmonary vein then carries this blood to the lungs where it becomes oxygenated. Then the pulmonary vein carries the blood to the left atrium, where the bicuspid valve pumps it through to the left ventricle. Finally the aeorta takes the blood from the left ventricle, and pumps it to the rest of the body
What does the term oxygenated blood mean?
More oxygen, less carbon dioxide
What does the term deoxygenated blood mean?
More carbon dioxide, less oxygen
Which side of the ventricles walls are thicker and why?
The left as they are pumping blood all around the body, whilst the right are only pumping to the lungs
Why do ventricles have thicker walls than atrias/atriums?
Because they pump blood around the body, whilst the atrias only pump blood through the valves through to the ventricles
What happens when someone has coronary heart disease?
The heart muscle becomes too narrow, commonly due to a build up of fatty material. If the blood flow is reduced, then the supply of oxygen is also reduced, resulting in pain, a heart attack or even death.
How can coronary heart disease be solved?
A stent- small metal mesh is placed in the artery. A tiny balloon is then I faked to open up the blood vessel and the stent at the same time. The ballon is removed, but the stent remains, holding the artery open.
A bypass surgery- replacing the blocked arteries with parts of veins from other parts of the body. This is expensive and risky.
Statins- reduce blood cholesterol, this slowing down the levels at which fatty material is deposited in the coronary arteries m.
Why may valves leak?
The pressure over time can become too much
How can you fix a faulty valve?
Replace it with a mechanical valve or a biological valve
What is a disadvantage if a mechanical valve?
You would need to take medicine for the rest of your life to prevent clotting
What is a biological valve and what are the advantages and disadvantages?
A valve based on valves from animals like pigs
Advantage- no medicine needed
Disadvantage- only last 12-15 years