41. Some sponges overcome this limitation by adopting the " syconoid " structure, in which the body wall is pleated. 42. Many sea cucumbers have papillae, conical fleshy projections of the body wall with sensory tube feet at their apices. 43. It moves mainly by peristaltic action of its body wall , assisted to a limited extent by its tube feet. 44. Laparoscopic surgery is performed using a camera and instruments placed through small incisions ( ports ) in the body wall . 45. Many of the mesenteries project into the enteric cavity but some extend from the body wall to the central stomodaeum. 46. The Vestimentiferan tubeworms build the external chitin structure themselves by secreting chitin from specialized glands located in their body walls . 47. Because much of the bowel is not anchored to the body wall , it is free to move out of position. 48. There are no nephridia ( " little kidneys " ) or other diffuses out through the body wall and lophophore. 49. The integumentary nephridia lie attached to the inner side of the body wall in all segments except the first two. 50. Inside the body wall is the coelom which is divided by three longitudinal mesenteries which surround and support the internal organs.
