OCR Biology The circulatory system ( heart, blood & blood vessels)
How many chambers does the heart have?
4
What are the advantages of having a double circulatory system?
- blood gets pumped at a much higher pressure -helps the high amount of oxygen needed to maintain body temperature -increases rate of blood flow to tissues, more oxygen can be delivered to the cells
What could happen if a valve in the heart wasnt working properly?
- there could be a backflow of blood - blood pressure wouldnt be as high
List 4 adaptations specialised exchange organs have to maximise effectiveness.
- thin walls, so substances have a short distance to travel -large surface area, so lots of substances can move at once -lots of blood vessels, to get things into and out of the blood quickly -gas exchange surfaces are often ventilated too, air moves in and out
Alveoli are specialised to maximise the diffusion of oxygen and carbon dioxide. They have:
-An enormous surface area -Very thin walls -A moist lining for dissolving gases -A good blood supply
List 4 ways red blood cells are adapted to carry out their functions:
-biconcave disk shape, gives a large surface area: volume ratio. Helps absorbing and releasing oxygen -no nucleus, sames space for haemoglobin -small & flexible, able to fit in tiny capillaries -haemoglobin combines with oxygen to become oxyhaemoglobin, in body tissues revers happens to release oxygen to the cells.
List 3 adaptations of veins
-fairly thin outer wall -large lumen -thin layer of muscle and elastic fibres
List 3 adaptations of arteries
-small lumen -thick outerwall -thick layer of muscle and elastic fibres
List 3 adaptations of capillaries
-very small lumen -has a nucleus -wall made only one cell thick
What happens to the pressure in the artery when the heart A- contracts B- relaxes
A- pressure goes up B- pressure goes down
Where does gas exchange take place?
Air sacs called alveoli
Which type of blood vessel has a pulse?
Arteries
Why is the heart beat louder on the left side?
Because it has a higher pressure
Whats a common factor for heart disease?
Being overweight
Whats the name of the blood vessels that exchang materials with the tissues?
Capillary
What happens to carbon dioxide when the deoxygenated blood reaches the lungs?
Carbon dioide diffuses out of the blood and into the lungs to be removed from the body
Explain how oxygen and glucose move in and out of the blood.
Diffusion through capillaries
Whats the function of platelets?
Helps blood clots
Arrange the 3 types of blood vessels into order according to the pressure of blood inside them.
Highest- Arteries Capillaries Lowest- Veins
Whats the function of capillaries?
Involved in the exchange of materials at the tissue
What is plasmas job?
Its the pale yellow liquid which carries everything that needs transporting around the body.
Why do large multicellular organisms need transport systems while simple unicellular organisms do not?
Large multicellular organisms have a much smaller surface area to volume ratio compared to smaller organisms.
Which chamber produces the highest pressure in blood?
Left ventricle
Which of the following carry oxygenated and deoxygenated blood? Pulmonary vein, aorta, vena cava, left ventricle, left atrium, pulmonary artery, right ventricle, right atrium.
Oxygenated- Aorta Pulmonary Vein Left Ventricle Left Atruim Deoxygenated- Vena cava Pulmonary Artery Right Ventricle Right Atrium
What are the 4 components of blood?
Plasma Red blood cells White blood cells Platelets
Which vessel takes blood from the lungs to the heart?
Pulmonary vein
What are the four chambers of the heart called?
Right atruim Left atruim Right ventricle Left ventricle
From which chamber of the heart does blood leave to go to the lungs?
Right ventricle
What does pulmonary mean?
Something to do with lungs, eg- Pulmonary artery - towards the lungs Pulmonary vein - away from the lungs
What is the circulatory system comprised of?
The heart and blood vessels: Vein artery and capillary
Which chamber of the heart pumps deoxygenated blood to the lungs?
The right ventricle
What is meant by a closed systems?
The vessels stay in loops
What is meant by 'double circulatory system'?
There are two loops, blood goes through the heart twice. Once with oxygenated blood and the other with deoxygenated blood.
Whats the function of arteries?
To carry blood AWAY from the heart
Whats the function of veins?
To carry the blood BACK to the heart
Whats the function of valves?
To keep blood flowing in the correct direction
Whats the main job of the heart?
To pump blood around the body
What is the purpose of blood clotting after a skin wound?
To stop the loss of blood and prevent the entry of microorganisms into the body
Whats the job of the lungs?
To transfer oxygen to the blood and to remove waste carbon dioxide from the blood
Whats the function of red blood cells?
To transport oxygen from the lungs to all the cells in the body & carries haemoglobin
What does plasma contain?
Water Hormones Antibodies Digested food Carbon dioxide from body cells to lungs Red & white blood cells, platelets
