B3.2 Transport Systems in Plants and Animals Flashcards
- Specific to AQA Specification
What is the role of the circulatory system?
- To transport substances around the body through the blood stream
What is the heart?
- An organ that pumps blood around the body
What is the heart mostly made from?
- Muscle tissue
What are the four chambed of the heart?
- Right Atrium
- Right Ventricle
- Left Atrium
- Left Ventricle
Describe the double circulatory system starting with deoxygenated blood?
- Deoxyegenated blood enters right atrium via vena cava
- Atrium contracts, forcing blood into right ventricle
- Valve forces blood into pulmonary artery to the lungs to collect oxygen
- Oxygenated blood comes back to the heart from the lungs via the pulmonary vein
- Blood goes into the left atrium, to the left ventricle
- Valve forces blood into aorta artery to the rest of the body
What do arteries carry?
- Takes oxygenated blood away from the heart
What are the features of arteries?
- Thick walls comared to lumen
- Thick layers of muscles to make walls strong
- Elastic fibres for it to stretch and spring back
Why do arteries have strong walls?
- Heart pumps blood at high pressure so artery walls need to be strong and elastic
What are the features of veins?
- Have bigger lumens than arteries
- Have thinner walls that arteries due to lower pressures of blood flow
- Valves
What do veins carry?
- Deoxygenated blood back to the body
What are the purposes of valves?
- To prevent the backflow of blood
What are capillaries?
- Very small (one cell thick) blood vessels
What are the purpose of capillaries?
- To carry blood close to every cell to exchange substances
What are the features of capillaries?
- Permeable walls to allow the exchange of substances
What is coronary heart disease?
- When blood is blocked by fatty deposits which narrow blood flow and may lead to heart attacks by reduction of oxygen
How is coronary heart disease prevented?
- The use of stents which keep arteries open
What are the problems with stents?
- Could damge arteries
- Irritate arteries, causing infection
What is blood?
- A tissue
What does blood contain?
- A fluid called plasma in which red blood cells, white blood cells and platelets are suspended
What is plasma?
- A straw coloured liquid
What does plasma carry?
- All other blood cells
- Carbon dioxide from the organs to lungs
- Soluble food molecules from the small intestines to other organs
- Urea from the liver to the kidneys
What is the purpose of red blood cells?
- To transport oxygen from the lungs to the organs
How are red blood cells adapted?
- No nucleus, more room for oxygen
- Bioconcave shape to increase surface area
- Contain red pigment called haemoglobin
How does red blood cells carry and release oxygen?
- In the lungs, haemoglobin combines with oxygen to form oxyhaemoglobin
- In the organs, oxyhaemoglobin splits to release oxygen and haemoglobin
What are the purpose of white blood cells?
Defend the body against infection:
- Phagocytes kill micobes by consuming
- Lymphocytes produce chemiclas and antibodies
What are platelets?
- Small fragments of cells with no nucleus
What are the purpose of platelets?
- Clot wounds preventing blood loss
What occurs in the xylem tissue in plants?
- Transports water and minerals from the roots to the stem and leaves
- Transpiration stream
What happens in the phloem tissue in plants?
- Carry dissolved sugars from the leaves to the rest of the plant, including growing regions and storage organs
