Sixth Entry

I wonder what goes on in the tiny body of a spider.

Therefore I decided to find out more and I clearly learned much more from this piece of research.

The mouth parts of the spider include the coxa of the pedipalps which have been modified as chewing mouth parts. They are often serrated as it is these the spider uses to bite a hole in the skin, or exoskeleton of its prey. The parts of the coxa that function as mouth parts are called maxillae. Apart from their cutting edge the maxillae also have a a filtering edge covered in fine hairs that prevents solid particles from entering the spiders mouth. This filtering system is so fine that only particles smaller than 1 micron (0.001 of a mm) can pass through.

The maxillae form the sides of the mouth. To the front of the mouth is a hinged and movable organ called the rostrum and to the back of the mouth is the labium. Behind the mouth is pharynx a short tube lined with microscopic teeth that also filter the incoming fluid. The pharynx leads into the oesophagus, another tube through the food reaches the sucking stomach. This sucking stomach is a muscularly driven pump that draws the spiders liquid food into its digestive system, there are valves at both the entrance and exit of the stomach that ensure the food only passes one way through the system.

The midgut, or intestine starts immediately behind the stomach and leads from the prosoma to the opisthosoma via a tube that passes through the pedicel. From the midgut two branches or diverticula extend out into the prosoma, in most species they even extend into the coxa of the walking legs. In the opisthosoma there are many of these diverticula branch off from the midgut and surround the other organs present there. At the end of the midgut is the stercoral pocket (cloacal chamber) this is a storage area for wastes which are eventually passed along the short hind gut and out of the body via the anus.

Creepy Video:



Links/Resources:

http://www.everythingabout.net/articles/biology/animals/arthropods/arachnids/spiders/ http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=761566464&pn=3
http://en.wikipedia.org/wiki/Spider