capillaries

Question 1

what materials are transported by capillaries?

Answer 1

oxygen, glucose and amino acids are diffused from blood into tissue fluid, and into body cells. carbon dioxide and urea diffuse from the cells into tissue fluid, then into the blood for excretion for removal

Question 2

how does tissue fluid aid in the transport of substances in capillaries

Answer 2

tissue fluid bathes the cells of tissues, and provides a medium for diffusion to allow for exchange of materials between capillaries and body cells. the main force that oushes plasma out of blood is hydrostatic pressire, which is the blood pressure against capillary wall

Question 3

what are some structural adaptations of capillaries?

Answer 3

1. capillary walls are one-cell thick
2. small gaps between endothelial cells
3. large network of capillaries

Question 4

what are the functions of these structural adaptations?

Answer 4

1. for quick diffusion of substances between blood and body cells
   2, causes some components of blood to leak from plasma, and allows leucocytes to squeeze through but are too small for large molecules to pass through
   3, large total surface area available for diffusion, blood pressure in capillaries is low, velocity of blood is low, and allows more time for diffusion of substances to take place