restriction. n. 1. something that restricts; a restrictive measure, law, etc. 2. the act of restricting or the state of being restricted. 3. (Logic) logic maths a condition that imposes a constraint on the possible values of a variable or on the domain of arguments of a function.
The primitive gut that forms during gastrulation in the developing embryo is known as the archenteron or the digestive tube.It develops into the digestive tract of an animal.ach is controlled by the dorsal blastopore, and primitive node (also known as Hensen's node), respectively. During Gastrulation, the Archenteron develops into the digestive tube, with the blastopore developing into either the mouth (Protostome) or the anus (Deuterostome).
The human gastrointestinal tract is the stomach and intestine, sometimes including all the structures from the mouth to the anus. (The  digestive system  is a broader term that includes other structures, including the accessory organs of digestion).In an adult male human, the gastrointestinal (GI) tract is 5 metres long in a live subject, or up to 9 metres without the effect of muscle tone, and consists of the upper and lower GI tracts.The  digestive system  is a broader term that includes other structures, including the accessory organs of digestion). In an adult male human, the gastrointestinal (GI) tract is 5 metres long in a live subject, or up to 9 metres without the effect of muscle tone, and consists of the upper and lower GI tracts.