GENERAL HISTOLOGY

Detailed explanation-1: -The entire structure is called a tube foot. In most cases, the small lateral canals connecting the ampullae to the radial canal are of equal length, so that the tube feet are arranged in two rows, one along each side of the groove.

Detailed explanation-2: -(7) Lateral Canal :-In each arm, the radial canal gives out two series of short, narrow, transverse branches called lateral or podial canals. Each lateral canal is attached to the base of a tube foot and its provided with a valve to prevent backward flow of fluid into the radial canal.

Detailed explanation-3: -The radial canals carry water to the ampullae and provide suction to the tube feet. The tube feet latch on to surfaces and move in a wave, with one body section attaching to the surfaces as another releases. Most sea stars cannot move quickly.

Detailed explanation-4: -The ring canal connects the radial canals (there are five in a pentaradial animal), and the radial canals move water into the ampullae, which have tube feet through which the water moves.

Detailed explanation-5: -Stone canal walls are supported by a series of calcareous rings. Note: Stone canal of starfish takes part in the vascular system. It works as follows-Water enters through the madreporite and flows through the stone canal. It connects to the circular ring canal surrounding the mouth.