Blood & Circulation

Question 1

write down the stps to drawing and labelling the heart including your reasoning and logic

Answer 1

1. draw a heat shape
2. label septum in the middle
3. labell 4 quadrants
4. Oh my LORD, Left oxygenated right deoxygenated
5. draw vena cava going into right atrium-vena cava carries deoxygenated blood from the body, atrium accepts blood from the body.
6. label tricuspid valves
7. label semilunar valves
8. label pulmonary artery-pulmonary artery takes deoxygenated blood AWAY from the heart to the lungs
9. label pulmonary vein
10. label bicuspid valves
11. label aorta

Question 2

what does directly proportional look like on a graph (2)

Answer 2

straight line, going through the origin

Question 3

what does surface area to volume ratio mean, and how does it relate to the size of the animal (2)

Answer 3

Organisms that are large have a small SA:V

This means they need a transport system as just diffusing/osmosing substances is not nearly efficient enough

Question 4

what is blood and what is plasma, what is plasma made of, and what does blood do (4)

Answer 4

Blood is a tissue based on liquid - plasma

This plasma carried the red blood cells, white blood cells, platelets and dissolved substances (includes hormones)

Blood:

Transports oxygen
Removes the waste product CO2 by carrying it to the lungs
Carries urea from the liver (where it is broken down from excess proteins) to the kidneys
Carries the small soluble of digestion to the cells that need it

Question 5

what are the adaptations of the RBC (3)

Answer 5

Red Blood Cell Adaptations:

Biconcave Shape - increased SA:V to make diffusion more efficient
Packed with red pigment - haemoglobin - which binds with oxygen in a reversible reaction
No nucleus - to maximise space for haemoglobin

Question 6

how much percentage of plasma is in the blood and what is adrenaline and its effects and where its released from (4)

Answer 6

Around 55% of the blood is plasma
Adrenaline is released from the adrenal glands (sit on top of the kidneys)
Adrenaline triggers a fight or flight response
Adrenaline increases heart rate, which supplies oxygen at an increased rate to the muscles, giving them a lot of energy, preparing your body to use this energy to run or to fight

Question 7

describe heart rate , if it is volunatary or involuntary, the purpose of the heart, the path off the electric signals and how the body increases heart rate (9)

Answer 7

Heart rate is controlled by your involuntary nervous system
The whole point of the heart is to deliver oxygen to all the cells in the body
The body recognises this failing when CO2 levels increase
So, when CO2 levels increase, this is detected by receptors in your aorta and your carotid artery (takes blood to your brain)
These receptors pass on the signals to the medulla in the brain. The higher the CO2 levels, the higher the firing rate of rate of signals. When there is a higher firing rate, the medulla sends signals along the accelerator nerve, increasing heart rate
When the nerve firing becomes too slow (if CO2 levels fall too low), the medulla sends signals along the decelerator nerve, to decrease heart rate