B4 - Organising Animals And Plants Flashcards
What does the circulatory system transport
Respiratory gases
Blood high in oxygen is known as
Oxygenated
Blood low in oxygen is known as
Deoxygenated
Section of the right side of the system including right side of heart deals with
Deoxygenated blood
Section of of the system including left side of heart deals with
Oxygenated blood
What is blood
Blood is a unique tissue based on a liquid called plasma
Red blood cells
Picks up oxygen from air in lungs and carries it to cells needed. Packed with red pigment called haemoglobin and these bind to oxygen. Biconcave disks, no nucleus for more space for haemoglobin.
White blood cells
Bigger than red blood cells. Fewer of them. Part of body’s defence system against harmful microorganisms. Some form antitoxins against poisons made by microorganisms. Others engulf and digest invading bacteria and viruses. Has a nucleus.
Platelets
Small fragments of cells. Helps blood clot at wounds. Has no nucleus.
Veins
Relatively thin walls, large lumen (hole in centre) and often has valves.
Veins carry away deoxygenated blood away from organs towards heart.
Blood is low in oxygen so vein are a deep purple-red colour. Veins do not have a pulse. Thinner walls than arteries and often have valves to prevent back flow of blood.
Arteries
Thick walls made of muscle and elastic fibres, small lumen (hole)
Carries bright red oxygenated blood from heart to organs. Arteries stretch as the blood is forced through them and then go back into shape. You can feel this as a pulse. As the blood is under high pressure, it is very dangerous if an artery is cut because the blood will spurt out every time the heart beats.
The heart
Aorta, vena cava, semilunar valves, right atrium, tricuspid valve, right ventricle, pulmonary veins, left atrium, bicuspid valve, left ventricle
Has 4 chambers
Statins
Medicine which lowers cholesterol in one’s blood. This reduces the risk of vessel-related diseases. Could cause type 2 diabetes or higher blood sugar levels.
Stents
Tiny tube inserted into blocked passageway to help keep it open (in ducts, canals, blood vessel). Restores flow of blood ans other fluids. Effective for long time. Risk of developing blood clot near stent. Could damage artery.
Artificial pacemakers
Corrects problems with heart rate. Send electrical signals to heart to stimulate it to beat correctly. Very long-lasting. Infection could happen after surgery. Won’t treat heart diseases.
Artificial hearts
Temporary heart that supports a natural heart before it can be replaced. Helps people live a normal life while waiting for transplant. Risk of blood clotting - death. Very expensive.
Mechanical valves
Mechanical valves made of durable materials like titanium and polymers. Lasts a lifetime. However, patient needs to take blood thinning medicine forever to stop blood clotting around them. Good option for younger people.
Biological valves
Valves taken from animals or human donors. No medication required. Good for older people. Only lasts 12-15 years so every so often, surgery is required.
Closed double system
Blood stays in blood vessels and flows through heart on each complete circuit of the body.
Mesophyll tissue
Located between epidermal layers. Carries out photosynthesis as it contains chloroplasts and gas exchange takes place.
Epidermal tissues
Cover the surfaces of the leaf and protect them. Secretes a waxy substance that makes leaves waterproof.
Palisade mesophyll
Contains lots of chloroplasts, which carries out photosynthesis.
Spongy mesophyll
Contains some chloroplasts and also has big spaces ans large surface area to makes diffusion of gases easier.
Phloem
Transports sugars made by photosynthesis from the leaves to rest of the plant. This movement is called translocation. Phloem cells are alive.
Xylem
Transports water and mineral ions from soil to around the plant. This movement is called transpiration. Mature xylem cells are dead.
Guard cells
Size of stomata controlled by guard cells. Controls carbon dioxide going into leaf and water vapour and oxygen leaving it.
Transpiration in leaves
When stomata are open, water vapour is lost through them. This is called transpiration.
Transpiration stream
As water evaporates, more water is pulled up through xylem to take its place. The movement of water through the xylem is called the transpiration stream. Driven by evaporation of water from leaves so anything affecting rate of evaporation will also affect transpiration.
Factors that affect transpiration
Temperature, humidity, air flow, light intensity.
Transpiration is more rapid in hot, dry, windy, or bright conditions.
