Chapter 8 Flashcards
1
Q
Why are specialized transport systems needed? (5)
A
- Metabolic demands of multicellular animals is high.
- SA:V Ratio gets smaller as they get larger. Increased diffusion distances.
- Molecules such as hormones and enzymes may be present in 1 place but needed in another.
- Food needs to be transported from digestion organ to the needed cells.
- Waste products of metabolism need to be removed from cells and transported to the excretory organs.
2
Q
Does an open circulatory system carry oxygen and c02
A
No, Carries food and nitrogenous waste products.
3
Q
In a closed circulatory system, how can the amount of blood being transferred to different tissues.
A
They an be controlled by vasoconstriction and vasodilation.
4
Q
Name 3 components of blood vessels and explain them.
A
Elastic Fibres - Composed of elastin and can stretch and recoil, providing vessel walls with flexibility.
Smooth muscle - Contracts or relaxes, changes the size of the lumen
Collagen - Provides structural support to maintain the shape and volume of the vessel