circulation - transport in animals 2.59, 2.60, 2.61, 2.62, 2.63B, 2.69, 2.65, 2.66, 2.68, 2.64B, 2.67, 2.49

Question 1

what does the circulatory system need to function?

Answer 1

blood
heart
blood vessles

Question 2

what’s the blood vessel that goes from the lungs to the heart?

Answer 2

pulmonary vein

Question 3

whats the blood vessel that goes out the heart?

Answer 3

aorta

Question 4

whats the blood vessel that goes from the heart to the liver?

Answer 4

hepatic artery

Question 5

what’s the blood vessel that goes from the heart to the gut?

Answer 5

mesenteric artery

Question 6

what’s the blood vessel that goes from the heart to the kidneys?

Answer 6

renal artery

Question 7

what’s the blood vessel that goes from the kidneys to the heart?

Answer 7

renal vein

Question 8

what’s the blood vessel that goes from the gut to the liver?

Answer 8

hepatic portal vein

Question 9

what’s the blood vessel that goes from the liver to the heart?

Answer 9

hepatic vein

Question 10

what’s the blood vessel that goes to the heart?

Answer 10

vena cava

Question 11

what’s the blood vessel that goes from the heart to the lungs?

Answer 11

pulmonary artery

Question 12

what type of circulation do humans have?

Answer 12

double circulation

Question 13

when labelling the heart remember:

Answer 13

it is mirrored
our right is the left
our left is the right

Question 14

two things about the atrium:

Answer 14

top of heart
thin muscular walls

Question 15

two things about the ventricle:

Answer 15

below the atrium
thicker muscular walls (the left ventricle is the thickest to pump blood at higher pressures so blood can travel around whole body)

Question 16

is the right side of the heart oxygenated or deoxygenated?

Answer 16

deoxygenated - pumps blood to the lungs

Question 17

is the left side of the heart oxygenated or deoxygenated?

Answer 17

oxygenated - pumps blood to the body

Question 18

how does the heart pump blood?

Answer 18

atrium contracts emptying blood into the ventricles
ventricles then contract pushing blood into arteries
valves close to ensure blood flows in right direction

Question 19

how does exercise affect heart rate?

Answer 19

if we exercise our muscles need more glucose and oxygen for aerobic respiration therefore the heart rate increases so more blood travels to muscles

Question 20

what happens to our bodies when our heart rate increases due to exercise?

Answer 20

• muscles produce more carbon dioxide in aerobic respiration
• sensors in aorta and carotid artery detect this increase
• send nerve impulses to the medulla
• medulla responds by sending nerve impulses along the accelerator nerve
• accelerator nerve increases heart rate
• blood is supplied to muscles to meet the demands of increased aerobic respiration

Question 21

what happens when we are scared or angry?

Answer 21

heart rate increases
triggered by the secretion of the hormone adrenaline

Question 22

what direction do arteries carry blood?

Answer 22

away from the heart

Question 23

what direction do veins carry blood?

Answer 23

into the heart

Question 24

what’s the structure and function of arteries?

Answer 24

thick outer wall - can transport blood at high pressure
thick layer of elastic tissue - allows artery to stretch and recoil to keep blood flowing at high pressure
thick layer of muscular tissue - helps control flow of blood by widening and narrowing
small lumen

Question 25

what's the structure and function of veins?

Answer 25

thin outer wall - blood is flowing at low pressure so a thick wall is not needed thin layer of muscle and elastic tissue - wall can contract and keep blood flowing semilunar valves - prevents blood flowing backwards large lumen

Question 26

what's the structure and function of capillaries?

Answer 26

wall is one cell thick - short distance of diffusion of substances from blood into tissues very small lumen

Question 27

what is coronary heart disease?

Answer 27

coronary arteries supply the heart with blood that contains glucose and oxygen which is needed for aerobic respiration and the removal of carbon dioxide if you have fatty deposits build up the artery walls the fatty deposits narrow the lumen, therefore, restricting blood flow to heart muscle cells in result, heart muscles receive less oxygen and aerobic respiration decreases and anaerobic respiration increases lactic acid will build up causing heart attacks

Question 28

what are some risk factors that make coronary heart disease more likely?

Answer 28

diet - eating saturated fat increases blood cholesterol and increases the risk of fatty deposits smoking - increases blood pressure and increases fatty deposits forming high blood pressure - damages artery lining obesity - increase blood pressure and poor diet lack of exercise - high blood pressure

Question 29

which part of the brain controls heart rate?

Answer 29

changes in heart rate are controlled by nerve impulses from the medulla

Question 30

what does blood contain?

Answer 30

plasma red blood cells platelets phagocytes (white blood cells) lymphocytes (white blood cells)

Question 31

what is the plasma?

Answer 31

straw coloured liquid transports blood cells and many other substances including: dissolved nutrients such as glucose and amino acids: dissolved waste products including urea and carbon dioxide: hormones: proteins: heat energy

Question 32

what are the red blood cells?

Answer 32

small red cells transport oxygen, bound to haemoglobin

Question 33

what are platelets?

Answer 33

cell fragments release chemicals when the blood is exposed to air, which causes soluble fibrinogen to be converted to insoluble fibrin fibrin forms a mesh which traps platelets and red blood cells this is a clot (scab)

Question 34

what are phagocytes (white blood cells)?

Answer 34

larger cells with multi-lobed nucleus engulf and digest pathogens (microorganisms which cause diseases)

Question 35

what are lymphocytes (white blood cells)?

Answer 35

cells with a very large nucleus make and release Y shaped proteins called antibodies, which bind to and destroy pathogens

Question 36

how are red blood cells specialised for their job?

Answer 36

rbc's contain haemoglobin (a protein which forms with oxygen to form oxyhaemoglobin) - transporting oxygen to respiring cells they have no nucleus - meaning more haemoglobin can be packed into each cell - so more oxygen can be transported they are a biconcave shape - increasing surface area - increasing volume ratio and decreasing the distance to the centre of the cell - increasing rate of diffusion

Question 37

what is blood clotting?

Answer 37

platelets are fragments of larger cells and if platelets are exposed to oxygen they realise chemicals which start clotting process the chemicals cause the double plasma protein fibrinogen to be changed into the insoluble fibrous protein fibrin the fibrin forms a network of fibres across the cut which traps platelets and red blood cells this forms a clot or scab which prevents further blood loss also preventing entry of pathogens clots can form within blood vessels if plaques cause rbc to be broken causing heart attacks

Question 38

what do arteries do?

Answer 38

pumps the blood at high pressures

Question 39

what do capillaries do?

Answer 39

arteries branch into capillaries carry the blood really close to cells in the body in order to exchange with them they have permeable walls so they can diffuse in and out they supply food and oxygen and take and waste CO2

Question 40

what do veins do?

Answer 40

blood is at a low pressure

Question 41

what is a disease?

Answer 41

a condition that prevents the body or part of it not working properly most diseases are caused by micro-organisms (pathogens) entering the body and feeding and reproducing in it they damage the body but excreting toxic waste substances called toxins

Question 42

how do phagocytes do their job?

Answer 42

1. phagocyte recognises pathogen 2. phagocyte engulfs pathogen in process known as phagocytosis 3. the lysozymes containing enzymes move towards the pathogen 4. enzymes break down pathogen 5. useful materials are absorbed 6. waste products are removed from the phagocyte

Question 43

how do lymphocytes do their job?

Answer 43

1. lymphocytes detect pathogen's antigens 2. lymphocytes identifies the correct type of antibody to make, which is complementary to the pathogen's antigen 3. lymphocyte releases large numbers of correct antibody 4. pathogens either clump together resulting in death or the antibodies trigger phagocytes, some pathogens can even burst 5. lymphocytes produce cells that produce lots of antibodies very quickly if they detect the same pathogen again, these are called memory cells

Question 44

what are anti-toxins?

Answer 44

some anti bodies are specialised to combat toxins, chemicals released by the pathogen which cause cell damage

Question 45

what are memory cells and what is their role?

Answer 45

- prevents the body being infected by the same pathogen again and again - lymphocytes produce memory cells, they can remain in our circulatory system for a life time - when body encounters same pathogen, memory cells react to the pathogen very quickly producing lots of antibodies much earlier than the first time - kills the pathogen before we feel ill and prevents us from being ill twice with the same pathogen = gained immunity

Question 46

what are vaccines and how do they link to memory cells?

Answer 46

- the body is given a vaccine which is a dose of the pathogen - either dead pathogen or parts of pathogen's cell surface = stopping pathogen from causing a disease - lymphocytes generate antibodies against the pathogen and more importantly make memory cells = vaccines give immunity the graph shows how the second response of the lymphocytes is quicker and larger