Topic 3 - Mass transport in mammals/ Animals

Question 1

In mammals is the circulatory system double or single?

Answer 1

Double

Question 2

What arteries supply blood to the heart?

Answer 2

Coronary arteries

Question 3

Heart -> lungs

Answer 3

Pulmonary artery

Question 4

Lungs -> heart

Answer 4

Pulmonary vein

Question 5

Heart -> body

Answer 5

Aorta (high pressure)

Question 6

Body -> heart

Answer 6

Vena cava

Question 7

What takes oxygenated blood in the kidneys?

Answer 7

Renal artery

Question 8

What takes deoxygenated blood out of kidneys?

Answer 8

Renal vein

Question 9

What steps does blood travel through (from coming into heart to leaving to the body?)

Answer 9

1. Vena cava -> R atrium (deoxygenated).
2. R Atrium contracts -> R Ventricle (deoxygenated)
3. R Ventricle contracts -> pulmonary artery
4. Lungs -> pulmonary vein
5. Pulmonary vein -> L Atrium (oxygenated)
6. L Atrium contracts -> L ventricle
7. L ventricle contracts -> aorta

Question 10

Difference between left side of heart and right side of heart.

Answer 10

Left side of heart has thicker walls due to pumping body to whole of body which has to be higher pressure.

Question 11

Pathway of a red blood cell from kidney to lungs

Answer 11

• leaves kidney -> renal vein
• enters heart -> vena cava, R atrium, R ventricle
• to lungs -> pulmonary artery

Question 12

Characteristics of a vein

Answer 12

• wide lumen
• thinner muscle wall

Question 13

How is water from tissue fluid returned to the circulatory system?

Answer 13

• Plasma proteins remain in blood
• so creates WP gradient
• water moves to blood ( by OSMOSIS)
• returns to blood by lymphatic system

Question 14

Suggest two ways the scientific drawing could be improved?

Answer 14

• add labels
• no shading

Question 15

What 3 precautions should be taken after a dissection?

Answer 15

• disinfect tools
• disinfect hands
• wear gloves

Question 16

How do arterioles reduce blood flow into capillaries?

Answer 16

• muscle contracts
• narrows lumen
• reduce blood flow into capillaries

Question 17

Heart muscle activity and blood movement between ventricles and arteries.

Answer 17

• ventricle muscle relax
• no blood back flow into ventricles

Question 18

Heart muscle activity and blood movement between atria and ventricles.

Answer 18

• atria muscle contracted
• blood movement from atria into ventricles

Question 19

What blood vessel carries blood at lowest blood pressure?

Answer 19

Vena Cava

Question 20

Why has the rate of blood flow not yet increased in the aorta despite the pressure in the L ventricle increasing?

Answer 20

• Semi-lunar valve closed
• bc pressure in aorta still higher than in ventricle

Question 21

After the rate of blood flow and pressure in the aorta near to the heart has decreased there is a small peak. Why does this happen and why is it important?

Answer 21

• it is elastic recoil
• smooths the blood flow

Question 22

How would a graph of right ventricle pressure be similar and differ from the graph diagram of the left ventricle?

Answer 22

Similarity
- peaks at same point
Difference
- lower pressure

Question 23

What’s the advantage of the Bohr effect during intense exercise?

Answer 23

• Increase in pCO2 from respiration of muscles during exercise decreases oxygen affinity.
• increases dissociation of O2
• for aerobic respiration at the tissues/ muscles

Question 24

Increased exercise intensity produces a higher volume of CO2.
However pCO2 in air breathed out didn’t show a large increase during exercise.
What physiologic change would cause this and why?

Answer 24

• inc breathing rate
• similar pCO2 per breath -> however more breaths

Question 25

If a drug used increases the percentage of red blood cells in blood how can overuse of it lead to higher risk of a heart attack?

Answer 25

- drug causes the blood to thicken - so inc risk of it blocking coronary artery - blocking blood flow to heart - causing heart attack

Question 26

Why should athletes not be allowed to use performance enhancing drugs?

Answer 26

- some will gain a bigger advantage - health risks

Question 27

How does increasing CO2 conc affect the dissociation of oxyhaemoglobin?

Answer 27

- Increasing pCO2 decreases oxygen affinity - by dec blood pH - oxygen dissociates from the haemorrhage molecule more readily

Question 28

Using info from graph to explain how named animal myoglobin dissociation curve makes it more adapted for a particular function

Answer 28

- does oxygen dissociate more or less readily? - if less readily -> allows aerobic respiration when at lower pO2

Question 29

How do semilunar valves maintain unidirectional flow of blood?

Answer 29

- pressure in left atrium higher than in left ventricle - so valve opens - pressure in left ventricle higher than in left atrium - so valve closes

Question 30

How could having caffeine increase heart rate?

Answer 30

- more action potentials along sympathetic nervous system pathway - to SAN increasing the heart rate

Question 31

Why does binding one molecule of oxygen to haemoglobin make it easier for a second oxygen molecule to bind?

Answer 31

- because it changes the tertiary 3D structure of the binding site for O2 - creating another binding site for the 2nd O2

Question 32

What is the role of the heart in forming tissue fluid?

Answer 32

- contraction of ventricles produces high blood (hydrostatic) pressure - this forces water out of blood capillaries.

Question 33

Suggest how blockages in the lymph system lead to swelling?

Answer 33

excess tissue fluid cannot be reabsorbed so builds up

Question 34

How do the changes in the shape of haemoglobin result in the S-shaped oxyhaemoglobin dissociation curve for adult haemoglobin?

Answer 34

- First oxygen binds to haemoglobin causing a change in it's shape. - the shape then allows more O2 to bind easily

Question 35

Why is babies changing from feral to adult haemoglobin beneficial?

Answer 35

- adult haemoglobin has a lower affinity for O2 at low partial pressures - easier unloading of O2 for aerobic respiration

Question 36

Suggest how a treatment can help babies with sickle cell disease?

Answer 36

- SCD only affects HbA not HbF - treatment increases concentration of HbF -HbF has higher oxygen affinity for O2 - so higher proportion of HbF in blood means more O2 carried