Brain neurosecretory cells and their hormones, Biology

Assignment Help:

Brain Neurosecretory Cells and their Hormones

Kopec was the very first to suggest the role of hormones in controlling metamorphosis. On the base of his experiments on the larval gypsy moth (Porthetria dispar) he observed that at a specific period the brain releases a substance into the blood which is essential for pupation and therefore for metamorphosis. His findings on the role of brain hormones in metamorphosis of insects was supported by consequent workers who found similar mechanisms in dissimilar insect groups. Large secretory nerve cells in the brain of the insects called neurosecretory nerves were as well identified as being responsible for affecting pupation. The secretion of these cells is known as activation hormone (AH) or brain hormone (BH). The activation hormone is comprised of proteins or Lipoproteins. The AH or BH after synthesis pass together the axons of these cells and end blindly into a pair of storage and release organs called the corpora cardiaca (CC), situated in the posterior brain. The CC releases the active hormone material termed as prothoracicotropic hormone (PTTH) which is a small polypeptide. This prothoracicotropic hormone acts on the prothoracic gland, causing it to secrete the moulting hormone known as 'ecdysone'.


Related Discussions:- Brain neurosecretory cells and their hormones

Nucleolus, NUCLEOLUS Discovered by Fontana and name given by Bowm...

NUCLEOLUS Discovered by Fontana and name given by Bowman. It is naked structure that is attached to chromatin at specific point called nucleolar organiser region or

Explain the parasympathetic neurons, Which of the following serves as an ac...

Which of the following serves as an actuating signal, or as part of an actuating signal, in a negative feedback system? A. Action potentials in the fibers of the diaphragm musc

Locomotion in star fish, LOCOMOTION IN STAR FISH - With the help of tub...

LOCOMOTION IN STAR FISH - With the help of tube feet aided by fluid pressure in them. In a tube feet upper ampulla, middle podium and lower sucker present.

Economically important fermentation products-beer, Normal 0 fal...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

What are cotyledons, What are cotyledons? Cotyledons, or seed leaves, a...

What are cotyledons? Cotyledons, or seed leaves, are structures formed by the embryo of angiosperms to absorb nutrients from the endosperm and to keep and transfer these nutrie

Echinococcosis (hydatidosis), Echinococcosis (hydatidosis) Echinococco...

Echinococcosis (hydatidosis) Echinococcosis, also called hydatidosis, is a global problem particularly in countries where sheep and cattle raising forms the major animal husba

Peri operative myocardial infarction, Peri operative Myocardial Infarction ...

Peri operative Myocardial Infarction :  Peri operative Myocardial Infarction is diagnosed by the appearance of fresh Q waves. Non-Q, myocardial infarction is suspected when there

Trinomial systeem of nomenclature, can you tell 10 examples of trinomial sy...

can you tell 10 examples of trinomial system of nomenclature?

Explain spontaneous closure of defects in details, Explain Spontaneous Clos...

Explain Spontaneous Closure of Defects in details? Some defects have a tendency towards spontaneous closure and this can influence the timing of intervention. The defects known

What is the significance of the -r group in amino acid, What is the signifi...

What is the significance of the -R group (variable radical) in an amino acid molecule? The -R group, also known as a lateral chain, is the variable part of the amino acid molec

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd