Topic 3.2 - Mass Transport In Animals

Question 1

What is the process by which haemoglobin binds with oxygen called? There are two names.

Answer 1

Loading or Associating.

Question 2

What is the process by which haemoglobin releases its oxygen called? There are two names.

Answer 2

Unloading or Dissociating.

Question 3

Haemoglobin with a high affinity do what?

Answer 3

Take up oxygen more readily and release it less readily.

Question 4

Haemoglobin with a low affinity do what?

Answer 4

Take up oxygen less readily but release it more readily.

Question 5

On oxygen dissociation curve, what does the furthest left of the curve tell you?

Answer 5

That there is a greater affinity for oxygen, so it loads oxygen more readily but unloads it less readily.

Question 6

On oxygen dissociation curve, what does the furthest right of the curve tell you?

Answer 6

That there is a lower affinity for oxygen, so it unloads oxygen more readily but loads it less readily.

Question 7

What takes blood from the heart to the heart to the rest of the body? Oxygenated or Deoxygenated?

Answer 7

Oxygenated blood is taken by the Aorta.

Question 8

The aorta branches into other major arteries, which one takes oxygenated blood to the liver?

Answer 8

Hepatic Artery.

Question 9

The aorta branches into other major arteries, which one takes oxygenated blood to the kidneys?

Answer 9

Renal Artery.

Question 10

The aorta branches into other major arteries, which one takes oxygenated blood to the lower/hind limbs?

Answer 10

Femoral Artery.

Question 11

The aorta branches into other major arteries, which one takes oxygenated blood to the upper/fore limbs?

Answer 11

Subclavian Artery.

Question 12

The aorta branches into other major arteries, which one takes oxygenated blood to the head and neck?

Answer 12

Carotid Artery.

Question 13

Which major vein brings back all the blood from the body to the heart? Oxygenated or Deoxygenated?

Answer 13

Deoxygenated blood is carried from the rest of the body to the heart by the Vena Cava. The superior bring it from the upper body and the inferior brings it from the lower body.

Question 14

The Vena Cava was originally branched. Which vein brings blood back from the lower/hind limbs?

Answer 14

Femoral Vein.

Question 15

The Vena Cava was originally branched. Which vein brings blood back from the kidneys?

Answer 15

Renal Vein.

Question 16

The Vena Cava was originally branched. Which vein brings blood back from the liver?

Answer 16

Hepatic Vein.

Question 17

The Vena Cava was originally branched. Which vein brings blood back from the upper/fore limbs?

Answer 17

Subclavian Artery.

Question 18

The Vena Cava was originally branched. Which vein brings blood back from the head and neck?

Answer 18

Jugular Veins.

Question 19

What takes deoxygenated blood from the heart to lungs?

Answer 19

Pulmonary Artery.

Question 20

What takes oxygenated blood from lungs to the heart?

Answer 20

Pulmonary Vein.

Question 21

Which arteries supply blood to the heart?

Answer 21

Coronary Artery.

Question 22

What happens if the coronary artery is blocked?

Answer 22

Heart becomes deprived of blood and oxygen and so can’t respire as much. This is called a myocardial infarction (aka heart attack).

Question 23

What are the 3 main blood vessels in the body?

Answer 23

1. Arteries.
2. Veins.
3. Capillaries.

Question 24

What are the main features of Arteries?

Answer 24

1. They have a thick collagen outer layer to resist any pressure changes.
2. They have a tick muscle and elastic layer, the muscle layer can cause vasoconstriction or vasodilation, and the elastic layer stretches to accommodate a pressure increase.
3. The lumen narrows allowing blood to be diverted.

Question 25

What are the main features of Veins?

Answer 25

1. The lumen is larger as lots of blood needs to flow back and there isn’t a lot of pressure.
2. The muscle and elastic layer are relatively thin as there isn’t a lot of pressure to withstand.
3. They have valves to prevent any back flow of blood.

Question 26

What are the main features of Capillaries?

Answer 26

1. Narrow lumen so narrow diameter.
2. Highly branched which increases number of them.
3. Single layer of epithelial cells, so have a short diffusion distance.

All these features help with rapid diffusion.

Question 27

What is the cardiac cycle?

Answer 27

The sequence of events in one heartbeat.

Question 28

What is Systole?

Answer 28

The contraction of heart muscles.

Question 29

What is diastole?

Answer 29

The relaxation of heart muscles.

Question 30

Does blood flow from high to low pressure, or low to high pressure?

Answer 30

High to low pressure.

Question 31

What are 2 ways to increase pressure?

Answer 31

1. Fill with blood.
2. Contract.

Question 32

What happens during Atrial Systole?

Answer 32

1. The atria contract, both at the same time. The pressure in the atria increases because of this.
2. Therefore, the pressure in the atria is greater than the pressure in the ventricle.
3. Because of this the atria-ventricular valve is forced downwards and opens, causing blood to flow from the atria into the ventricle.
4. At this stage the semi-lunar valves remain shut.

Question 33

What happens during Ventricular Systole?

Answer 33

1. The pressure in the atria is now lower than the ventricular pressure so the atrioventricular valve shuts, this creates the heartbeat ‘lub’ sound.
2. The ventricles contract (further increasing ventricular pressure).
3. The pressure in the aorta is lower than the ventricle so the semi-lunar valve opens and blood leaves the heart.

Question 34

What happens during Diastole?

Answer 34

1. All chambers are relaxed.
2. The pressure in the veins are greater than the pressure in the atria, so the blood flows back into the atria.
3. Back to Atrial systole.

Question 35

How is tissue fluid formed?

Answer 35

1. A very high hydrostatic pressure comes from the arterial end.
2. It forces water and small soluble nutrients out of the spaces between endothelial cells of the capillary walls.
3. The water and small soluble nutrients (glucose, amino acids, ions) form the tissue fluid.
4. Large molecules such as proteins (that are too big for the spaces) stay behind in the capillary and move towards the venule end of the capillary. This lowers the water potential in the capillary at the venule end.
5. Some of the water (excess) returns to the capillary via osmosis, down a water potential gradient through a semi-permeable membrane.
6. Any excess fluid enters the lymphatic vessels and is eventually returned to the circulatory system.