Fill in the blanks

(i) The …………… have thin and less muscular …………… , and have …………… to prevent back flow of …………… .

(ii) …………… carry blood to an organ and break up into …………… ending in capillaries.

(iii) Walls of capillaries consist of a single layer of squamous …………… cells.

(iv) The substances to and from the tissues diffuse through the walls of …………… .

(i) The auricles have thin and less muscular walls, and have Cuspid valves to prevent back flow of blood.

(ii) Arteries carry blood to an organ and break up into arterioles ending in capillaries.

(iii) Walls of capillaries consist of a single layer of squamous epithelial cells.

(iv) The substances to and from the tissues diffuse through the walls of capillary.