The brain is the center of the nervous system in all vertebrate and most invertebrate animals — only a few invertebrates such as sponges, jellyfish, adult sea squirts and starfish do not have one, even if diffuse neural tissue is present.

The relationship between brain size, body size and other variables has been studied across a wide range of vertebrate species.

The main subdivisions of the embryogenesis | embryonic vertebrate brain, which later differentiate into the forebrain, midbrain and hindbrain

Neuroanatomists usually divide the vertebrate brain into six main regions: the telencephalon ( cerebral hemispheres ), diencephalon ( thalamus and hypothalamus ), mesencephalon ( midbrain ), cerebellum, pons, and medulla oblongata.

Thousands of distinguishable areas can be identified within the vertebrate brain based on fine distinctions of neural structure, chemistry, and connectivity.

Although the same basic components are present in all vertebrate brains, some branches of vertebrate evolution have led to substantial distortions of brain geometry, especially in the forebrain area.

The main anatomical regions of the vertebrate brain, shown for shark and human.

Here is a list of some of the most important vertebrate brain components, along with a brief description of their functions as currently understood:

It has been demonstrated that neurogenesis can sometimes occur in the adult vertebrate brain, a finding that led to controversy in 1999.

The pterosaurs ' flocculi occupied 7. 5 % of the animals ' total brain mass, more than in any other vertebrate.

The front end of the nerve tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles: The prosencephalon ( forebrain ), mesencephalon ( midbrain ) and rhombencephalon ( hindbrain ), further differentiated in the various vertebrate groups.

Neurons are the core components of the brain, the vertebrate spinal cord, the invertebrate ventral nerve cord, and the peripheral nerves.

In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system ( CNS ) and is actually brain tissue.

The cephalopod retina does not originate as an outgrowth of the brain, as the vertebrate one does.

* Neuroglobin: a myoglobin-like haemprotein expressed in vertebrate brain and retina, where it is involved in neuroprotection from damage due to hypoxia or ischemia.

This more realistic concept of the longitudinal structure of vertebrate brains implies that any section plane, except the sagittal plane, will intersect variably different parts of the same brain as the section series proceeds across it ( relativity of actual sections with regard to topological morphological status in the ideal unbent neural tube ).

In the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord.

A Critique of the paper: " Do fish have nociceptors: Evidence for the evolution of a vertebrate sensory system "</</ ref > Rose argues that since the fish brain is rather different from ours, fish are not conscious, whence reactions similar to human reactions to pain instead have other causes.

In vertebrate anatomy the brainstem ( or brain stem ) is the posterior part of the brain, adjoining and structurally continuous with the spinal cord.

When the molecules are so combined as to form the brain and nervous system of a vertebrate, the corresponding elements of mind-stuff are so combined as to form some kind of consciousness ; that is to say, changes in the complex which take place at the same time get so linked together that the repetition of one implies the repetition of the other.

The pineal gland ( also called the pineal body, epiphysis cerebri, epiphysis, conarium or the " third eye ") is a small endocrine gland in the vertebrate brain.

But even in relatively primitive laboratory animals such as the rat, sex activity closely identified with the hypothalamus and the visceral brain is enhanced by the neocortex.

The visceral brain as well as the neocortex is known to contribute to memory, but this topic is beyond the scope of this paper.

or, to put the same thing in physiological terms, that the performance-capacity of the tactual apparatus, from the periphery up to the tactual centers in the brain, -- that is, from one end to the other -- was unimpaired ''.

There is nothing to suggest that the brain can alter past impressions to fit into an original, realistic and unbroken continuity like we experience in dreams.

As in the theory of perception, established in psycho-physiology, the eye is recognized as an integral part of the brain.

But then this theory confesses that it is completely at a loss as to how the image can possibly be received by the brain.

But why is it necessary to reproduce the retinal image within the brain??

As retinal images are conceded to be an integral function of the brain it seems logical to suppose that the nerves, between the inner brain and the eyes, carry the direct drive for cooperation from the various brain centers -- rather than to theorize on the transmission of an image which is already in required location.

If the photographically realistic continuity of dreams, however bizarre their combinations, denies that it is purely a composition of the brain, it must be compounded from views of diverse realities, although some of them may never be encountered in what we are pleased to call the real life.

Scientists assume that cholesterol ( from the Greek chole, meaning bile, and sterios, meaning solid ) is somehow necessary for the formation of brain cells, since it accounts for about 2% of the brain's total solid weight.

That part of the brain is called the posterior superior temporal cortex ( pSTC ).

The nervous system is basically the same as in other vertebrates, with a central brain, a spinal cord, and nerves throughout the body.

The amphibian brain is less well developed than that of reptiles, birds and mammals but is similar in morphology and function to that of a fish.

Elaborate arborization is important for it allows for the simultaneous transmission of messages to a large number of target neurons within a single region of the brain.

Acute disseminated encephalomyelitis ( ADEM ) is an immune mediated disease of the brain.

This is generally caused by dysfunction of the dorsal columns of the spinal cord, because they carry proprioceptive information up to the brain.

Arnold-Chiari malformation is a malformation of the brain.

While the improvements are attributed primarily to changes in the brain and not just the hip and / or ankle joints, it is still unknown whether the improvements are due to adaptations in the cerebellum or compensation by other areas of the brain.

Each is the size of a large asteroid, only capable surviving in microgravity conditions, and processes data at 0. 5 % the speed of a human brain.

The localizationist model is the original model, but modern anatomical techniques and analyses have shown that precise connections between brain regions and symptom classification don't exist.