Cephalisation - metazoa, Biology

Cephalisation - Metazoa

Bilateral animals when creeping or swimming, have a tendency to keep the same end of the body forward and the same surface down towards the substratum. In such a case the sensory organs and nervous system would also have a tendency to be concentrated at the anterior end. This differentiation of a 'head end' is known as cephalisation'(literal1y head development). Cephalisation has evolved to various degrees in bilateral animals.

2091_Cephalisation - Metazoa.png

                           Figure: Concentration of nervous system in anterior region of a) liver fluke b) Tapeworm c) Planaria

The mouth is usually located at the leading end with which become associated the organs for food capture, as the sensory organs on the head can detect food. Neurons become organized into brain in this region for rapid coordination; longitudinal nerve cords are developed for rapid transmission of information throughout the length of the body. Cephalisation in its most primitive form can be seen in Platyhelminthes.

Posted Date: 1/15/2013 2:28:14 AM | Location : United States







Related Discussions:- Cephalisation - metazoa, Assignment Help, Ask Question on Cephalisation - metazoa, Get Answer, Expert's Help, Cephalisation - metazoa Discussions

Write discussion on Cephalisation - metazoa
Your posts are moderated
Related Questions
Release of lysosomal enzymes from white blood cells during a local immune attack can contribute to the symptoms of inflammation. Suppose, to alleviate inflammation, you develop a d

Q. Why, even though they have an open circulatory system, can flying insects like flies beat their wings with great speed? In insects the circulatory system is open but this sy

Why is the human placenta referred to as haemochorial type? Name the hormone it secretes to facilitate parturition.

Explain CORONAW ARTERY DISEASE (CAD)? As far as CAD is concerned the people of South Asian region are at a very disadvantageous position. The term 'South Asians' includes perso

The principal nitrogenous excretory compound in humans is synthesised: 1. in kidneys but eliminated mostly through liver 2. in kidneys as well as eliminated by kidneys 3.

are viruses cellular organisms

Q. How does the intensity of facilitated diffusion differ in relation to the concentration of the moved substance? What is limiting factor? Like simple diffusion facilitated di

Describe cardiac rewabilptation and its various effects ? A survival benefit cannot be attributed solely to exercise training because many studies involved multifunctional inte

Class angiospermae (Flowering plants) Flowers are the reproductive structures. Ovules are protected within ovary, xylem vessels are present. After fertilisation the ovary develop

The measurement of blood sugar is of prime importance in the diagnosis and monitoring of patients with diabetes. You can refer sub-section 1.5.2 of Unit 1 to review about Glucose T