Transport

Question 1

Why do organisms need well-developed transport systems?

Answer 1

• Organisms have a low Sa:V ratio, long diffusion distance which decreases the rate of diffusion
• Insufficient for organism’s metabolic demand to maintain constant body temp/ respiration such as cells needing a high uptake of O2
• Maintain concentration gradients and removal of metabolites (CO2)

Question 2

What are the differences between mammals and fish circulatory system?

Answer 2

• Double/Single closed circulatory system
• Two atria/Two ventricles vs one atria/one ventricle
• Blood maintained at a higher pressure
• Mammals, blood pumped through heart twice in one circulation
• More efficient in mammals as transporting O2 to tissues to maintain constant body temp/ High Oxygen demand

Question 3

Describe the artery:

Answer 3

Function: Transport blood away from the heart
- Small lumen to maintain high blood pressure
- Elastic layer to allow for stretch recoil
- Smooth muscle to contract/relax to maintain blood pressure
- Collagen for structure and support/ withstand high blood pressure

Question 4

Describe the vein:

Answer 4

Function: Transport blood away from the heart
- Large lumen to carry large volume of blood
- Collagen to allow for structural support in transporting large volumes of blood
- Valves to prevent backflow

Question 5

Describe the capillary:

Answer 5

Function: Allow substances to be exchanged between cells
- High SA:V ratio
- Thin endothelium (one cell thick) to allow for short diffusion distance

Question 6

How is lymph different to tissue fluid?

Answer 6

Less oxygen and nutrients however more fatty acids