Further Animal Transport

Question 1

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

Answer 1

• Ventricles contract, pumping blood at high pressure through Arteries and Arterioles
• Water and other dissolved substances are forced out of Capillaries

Question 2

What is Oncotic Pressure?

Answer 2

Pressure exerted by proteins (e.g Albumin) in the blood plasma

Question 3

Describe the Structure of a vein.

Answer 3

• Wide lumen
• Thin layer of smooth muscle
• Elastic fibres
• Has valves

Question 4

Describe the structure of an artery.

Answer 4

• Narrow lumen
• Thick walls
• Thick layer of smooth muscle
• Elastic fibres

Question 5

Describe the structure of a capillary

Answer 5

• One cell thick
• Has pores

Question 6

Explain how water from tissue fluid is returned to the circulatory system

Answer 6

• Plasma proteins remain
• Reduces water potential of blood plasma
• Water moves into blood via osmosis
• Returns to blood via lymphatic system

Question 7

Explain how an arteriole can reduce blood flow into the capillaries

Answer 7

• Muscle contracts
• Narrows lumen of arteriole

Question 8

Describe the advantage of the Bohr Effect during intense exercise

Answer 8

• Increases dissociation of oxygen
• Oxygen can unload more easily for aerobic respiration at muscles

Question 9

Describe and explain the effect of increasing CO2 concentration on the dissociation of oxyhaemoglobin

Answer 9

• Increases oxygen dissociation (unloading)
• Decreases haemoglobin’s affinity for Oxygen.

Question 10

Binding of one molecule of oxygen to haemoglobin makes it easier for other O2 molecules to bind to Haemoglobin, explain why?

Answer 10

• Binding of first molecule changes tertiary structure of haemoglobin
• Uncovers another haem group for oxygen to bind to

Question 11

Describe the structure of haemoglobin

Answer 11

• Quaternary globular protein
• 2 alpha helixes and 2 beta chains
• Contains 4 Fe2+ haem groups (for oxygen binding)

Question 12

Explain how arteries are adapted to their function

Answer 12

• Elastic fibres allow wall to expand around blood passing through at high pressure, when heart relaxes, fibres recoil
• Narrow lumen to maintain high blood pressure
• Thicker walls to withstand higher blood pressure

Question 13

Explain how veins are adapted to their function

Answer 13

• Contains valves, to prevent backflow of blood