More Exchange & Transport Topic-3B

Question 1

Why is the circulatory system of mammals referred to as a double circulatory system?

Answer 1

There are two circuits, one taking blood from the heart to lungs and one back to the heart then to the rest of the body.

Question 2

Name the part of the heart that provides it with its own blood supply.

Answer 2

The coronary arteries

Question 3

Why are the pulmonary vein and artery different from usual?

Answer 3

As the vein carries oxygenated blood and the artery carries deoxygenated blood.

Question 4

What does the aorta do?

Answer 4

Supplies oxygenated blood to the body

Question 5

What does the vena cava do?

Answer 5

Supplies deoxygenated blood to the heart.

Question 6

The ……. vein and …….. artery can be associated with the kidneys.

Answer 6

The renal vein and renal artery can be associated with the kidneys.

Question 7

The hepatic vein and artery are associated with…?

Answer 7

The liver and gut

Question 8

The hepatic portal vein can be found….

Answer 8

Between the liver and the gut.

Question 9

Name adaptations of arteries

Answer 9

Walls are THICK and MUSCULAR
Walls have ELASTIC tissue to STRETCH and recoil as the heart beats (MAINTAINS HIGH PRESSURE)
endothelium is FOLDED allowing it to stretch.

Question 10

Name the role of arteries

Answer 10

Arteries carry blood from the heart to the rest of the body.

Question 11

Name the adaptations of veins

Answer 11

Wider lumen than arteries, have very little elastic or muscle tissue.
Valves to prevent backflow

Question 12

Name the roles of veins

Answer 12

Take blood back to the heart under low pressure.

Question 13

Name the roles of capillaries

Answer 13

Substances are exchanged between blood and body tissue at the capillaries.

Question 14

Name adaptations of capillaries.

Answer 14

Found very near cells in exchange tissues (short diffusion pathway)
Walls only one cell thick
Large number to increase surface area (capillary beds=a network of capillaries in tissue.

Question 15

What is tissue fluid?

Answer 15

The fluid that surrounds cells in tissues, made from small molecules that leave blood plasma(O2)

Question 16

Name factors that increase the risk of cardiovascular disease.

Answer 16

High blood cholesterol and poor diet
Cigarette smoking
high blood pressure
genetic factors

Question 17

Name the main stages of the cardiac cycle

Answer 17

Ventricles relax, atria contract
Ventricles contract, atria relax
Ventricles and atria relax

Question 18

Name the main stages of the cardiac cycle in order

Answer 18

Ventricles relax, atria contract
Ventricles contract, atria relax
Ventricles and atria relax

Question 19

How does blood get pushed into the ventricles?

Answer 19

The pressure increase due to volume decrease in the atria pushes the blood into the ventricles.

Question 20

What happens when the pressure in the ventricles becomes higher than the atria?

Answer 20

The atrioventricular valves are forced shut and due to pressure in ventricles being higher than pulmonary artery and aorta the semi-lunar valves are forced open.

Question 21

Why does the left ventricle have thicker muscular walls than the right ventricle?

Answer 21

Because it needs to contract powerfully to pump blood all the way round the body, not just to nearby lungs.

Question 22

Why do the ventricles have thicker walls than the atria?

Answer 22

Because they have to push blood out of the heart but the atria just push blood a short distance into the ventricles.

Question 23

Give the equation to calculate stroke volume

Answer 23

Stroke volume= cardiac output/heart rate

Question 24

Give 4 ways the aorta structure is related to its function

Answer 24

Thick walls to withstand high pressure
Elastic tissue to allow recoil
Muscle for contraction
Semi-lunar valves to prevent backflow of blood.

Question 25

Explain how tissue fluid is formed.

Answer 25

The overall hydrostatic pressure inside capillary is more than outside so small molecules are forced out of the capillary =tissue fluid.

Question 26

Why does the hydrostatic pressure fall from the arteriole end to the venule end of the capillary?

Answer 26

Due to the loss of fluid through the capillary lining.

Question 27

How does high blood pressure lead to an accumulation of tissue fluid?

Answer 27

High blood pressure=high hydrostatic pressure | Increases outward pressure of arterial end of capillary so more tissue fluid is formed.

Question 28

Why is the water potential of the blood plasma more negative at the venule end than the arteriole end of the capillary?

Answer 28

Water has left capillary but the proteins in the blood are too large to leave so the concentration of blood proteins is higher and thus water potential.

Question 29

Why would something be described as processed results?

Answer 29

Due to calculations being made from raw data

Question 30

How would you use given data to find water potential?

Answer 30

Plot graph with conc on x axis and % change in mass on y axis. Find where the curve crosses x axis use calibration table to find wp of sucrose concentration.

Question 31

Oxygen loads onto haemoglobin to form oxyhaemoglobin where there’s ..... ......

Answer 31

High pO2

Question 32

pO2 means....

Answer 32

Partial pressure of oxygen

Question 33

The greater the concentration of dissolved oxygen in cells = ....

Answer 33

Higher partial pressure

Question 34

Haemoglobin has a high ..... for oxygen

Answer 34

High affinity for O2

Question 35

When O2 leaves oxyhaemoglobinb(in lungs) it ......

Answer 35

dissociates

Question 36

Oxyhaemoglobin ...... it’s O2 where’s there’s ....... pO2

Answer 36

Oxyhaemoglobin unloads it’s O2 where there’s lower pO2

Question 37

Where in the body does oxygen load onto haemoglobin and why?

Answer 37

O2 enters blood capillaries at alveoli due to high pO2.

Question 38

When cells respire they .... .. ........ which lowers the ......

Answer 38

When cells respire they use up OXYGEN which lowers the pO2.

Question 39

Red blood cells deliver ........... to respiring tissues

Answer 39

Red blood cells deliver oxyhaemoglobin to respiring tissues where it unloads oxygen

Question 40

What does a dissociation curve show?

Answer 40

How saturated the haemoglobin is with oxygen at any partial pressure

Question 41

What does 0% saturation mean

Answer 41

None of the haemoglobin molecules are carrying oxygen.

Question 42

100% saturation means....

Answer 42

Every haemoglobin molecule is carrying the maximum of 4 molecules of oxygen.

Question 43

Where pO2 is high haemoglobin has a ..... affinity for oxygen

Answer 43

High affinity= pO2 high

Question 44

Where is pO2 expected to be high and where is it low?

Answer 44

High in the lungs | Low in respiring tissues

Question 45

Where pO2 is low haemoglobin has a ..... affinity for oxygen so it ...... it

Answer 45

Low affinity for oxygen so it releases it

Question 46

Why is the dissociation curve S shaped?

Answer 46

After first O2 molecule combines, shape changes to make it easier for other molecules to bind. But as Hb gets saturated it’s harder for oxygen molecules to join.

Question 47

How are organisms adapted to live in low concentration of oxygen environments

Answer 47

The dissociation curve moves left—> have higher affinity for oxygen than human

Question 48

How are organisms adapted that are very active and have high oxygen demand?

Answer 48

Haemoglobin with a lower affinity for oxygen so curbs is to the right.

Question 49

Oxygen dissociates more readily at ........ partial pressures of CO2

Answer 49

Higher partial pressure of CO2= readily dissociates oxygen

Question 50

Why does the dissociation curve shift right at higher pCO2? What is this effect?

Answer 50

The rate of dissociation of oxyhaemoglobin increases so curve shifts right. The Bohr effect.

Question 51

Give the formula for calculating the percentage saturation of haemoglobin with oxygen

Answer 51

(oxygenated haemoglobin/ | maximum saturation ) *100

Question 52

The oxygen dissociation curve of the fetus is to the left of that for its mother. Explain the advantage of this for the fetus.

Answer 52

Oxygen loads more readily at lower pO2, therefore oxygen moves from mother to fetus.

Question 53

After birth, fetal haemoglobin is replaced with adult haemoglobin. Use a graph to suggest the advantage of this to the baby.

Answer 53

oxygen dissociates to respiring tissues

Question 54

What does diastole mean?

Answer 54

Cardiac relaxation

Question 55

What does systole mean?

Answer 55

Cardiac contraction

Question 56

What makes the binding of the 2nd and 3rd oxygen easier?

Answer 56

The change in shape of the haemoglobin caused by the binding of the first oxygen.

Question 57

The two sets of intercostal muscles are said to be....

Answer 57

antagonistic.

Question 58

What type of process is Transpiration?

Answer 58

A passive on as the energy for the process comes from the sun.

Question 59

How can plants control the rate of transpiration?

Answer 59

By changing the size of their stomatal pores

Question 60

What is the main factor for movement of water up the xylem?

Answer 60

Cohesion and Tension (cohesion-tension theory)

Question 61

Haemoglobin with high affinity for oxygen takes it up more readily but also ….

Answer 61

releases it less readily.

Question 62

Haemoglobins affinity for oxygen varies depending on

Answer 62

the partial pressure of oxygen.

Question 63

Why is the 4th O2 molecule difficult to associate with Hb

Answer 63

Because the Hb has started to become saturated so it's harder for more oxygen molecules to join

Question 64

Why are the 2nd and 3rd O2 molecules easiest to associate with Hb

Answer 64

Because after the 1st O2 shape of Hb alters its shape so it's easier for other molecules to bind

Question 65

What is the xylem?

Answer 65

water transport tissue in plants composed of dead cells.

Question 66

What is translocation

Answer 66

the movement of materials (particularly sucrose) from the leaves to other parts of a plant.

Question 67

What is transpiration?

Answer 67

the loss of water from the leaves of a plant by evaporation.

Question 68

What is a sieve-tube element?

Answer 68

cellular structure in the phloem of plants that transports the products of photosynthesis throughout the plant by mass flow

Question 69

What 4 factors affect the transpiration rate?

Answer 69

Light Temperature Wind Humidity

Question 70

When a wave of electricity reaches the atrioventricular node there's a short delay before a new wave leaves. Explain the importance of this delay.

Answer 70

Allows Atria to empty before the ventricles contract.

Question 71

How to calculate stroke volume?

Answer 71

Cardiac output /beats per minute

Question 72

What causes the lumen of arteries to narrow in the formation of an atheroma?

Answer 72

Fibrous Plaques

Question 73

During a potometer experiment why do you cut the shoot underwater?

Answer 73

To prevent water entering the xylem

Question 74

How is the Xylem adapted for continuous flow of water?

Answer 74

No end walls for vessel elements so forms a continuous tube

Question 75

What does the potometer experiment calculate?

Answer 75

The rate of transpiration.

Question 76

List the things that result in uptake of water in a plant?

Answer 76

Transpiration (evaporation of water from leaves) which creates Tension (Hydrogen bonds between water and xylem vessels) Cohesion (H bonds between H2O) And diffusion of water into the roots via osmosis due to decrease in wp

Question 77

The Bohr effect means that oxygen....

Answer 77

dissociates at lower PO2

Question 78

Function of coronary arteries

Answer 78

Carry oxygen to heart muscle.

Question 79

What causes the increase in pressure of the heart

Answer 79

CONTRACTION

Question 80

How does ringing affect translocation

Answer 80

-Phloem removed when ring of bark taken so high conc of solute above ring as none can travel down phloem

Question 81

What is an atheroma?

Answer 81

fatty materials/cholesterol in artery wall

Question 82

Name 4 adaptations of capillaries

Answer 82

Pores in walls=faster filtration endothelium is one cell thick=shorter diffusion pathway narrow lumen=more time for diffusion small diameter=large SA/V ratio