What is the brain made of and?

Question

how does it retain charge/current and from where this current/charge comes from? Thanks. :)

Answer 1

Pictures and hot links at web page for:

The brain is made of three main parts: the forebrain, midbrain, and hindbrain. The forebrain consists of the cerebrum, thalamus, and hypothalamus (part of the limbic system). The midbrain consists of the tectum and tegmentum. The hindbrain is made of the cerebellum, pons and medulla. Often the midbrain, pons, and medulla are referred to together as the brainstem.


The Cerebrum: The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action. The cerebral cortex is divided into four sections, called "lobes": the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. Here is a visual representation of the cortex:

What do each of these lobes do?


Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving
Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli
Occipital Lobe- associated with visual processing
Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech
Note that the cerebral cortex is highly wrinkled. Essentially this makes the brain more efficient, because it can increase the surface area of the brain and the amount of neurons within it. We will discuss the relevance of the degree of cortical folding (or gyrencephalization) later. (Go here for more information about cortical folding)

A deep furrow divides the cerebrum into two halves, known as the left and right hemispheres. The two hemispheres look mostly symmetrical yet it has been shown that each side functions slightly different than the other. Sometimes the right hemisphere is associated with creativity and the left hemispheres is associated with logic abilities. The corpus callosum is a bundle of axons which connects these two hemispheres.

Nerve cells make up the gray surface of the cerebrum which is a little thicker than your thumb. White nerve fibers underneath carry signals between the nerve cells and other parts of the brain and body.

The neocortex occupies the bulk of the cerebrum. This is a six-layered structure of the cerebral cortex which is only found in mammals. It is thought that the neocortex is a recently evolved structure, and is associated with "higher" information processing by more fully evolved animals (such as humans, primates, dolphins, etc). For more information about the neocortex, click here.


The Cerebellum: The cerebellum, or "little brain", is similar to the cerebrum in that it has two hemispheres and has a highly folded surface or cortex. This structure is associated with regulation and coordination of movement, posture, and balance.

The cerebellum is assumed to be much older than the cerebrum, evolutionarily. What do I mean by this? In other words, animals which scientists assume to have evolved prior to humans, for example reptiles, do have developed cerebellums. However, reptiles do not have neocortex. Go here for more discussion of the neocortex or go to the following web site for a more detailed look at evolution of brain structures and intelligence: "Ask the Experts": Evolution and Intelligence

Limbic System: The limbic system, often referred to as the "emotional brain", is found buried within the cerebrum. Like the cerebellum, evolutionarily the structure is rather old.

This system contains the thalamus, hypothalamus, amygdala, and hippocampus. Here is a visual representation of this system, from a midsagittal view of the human brain:

Click on the words to learn what these structures do:


Thalamus
Hypothalamus
Amygdala
Hippocampus

Brain Stem: Underneath the limbic system is the brain stem. This structure is responsible for basic vital life functions such as breathing, heartbeat, and blood pressure. Scientists say that this is the "simplest" part of human brains because animals' entire brains, such as reptiles (who appear early on the evolutionary scale) resemble our brain stem. Look at a good example of this here.

The brain stem is made of the midbrain, pons, and medulla. Click on the words to learn what these structures do:


Midbrain
Pons
Medulla

Answer 2

The brain is made of essentially the same thing any other cell is made of, protiens, lipids, carbohydrates, nucleic acids, and water. The electrical activity arises from the active pumping of ions against their concentration gradients (and some other more complex actions, but they all rely on the pumping of sodium). By seperating positive and negative ions across a membrane, a resting membrane potential is created. All cells have a rmp, but in neurons, it's about -70 mV (much greater than other cells). This is the source of the electrical activity.

Answer 3

The brain is primarily made of two types of cells. Neuron cells, which have cell bodies (the grey matter), and many long dendrites (fibers) sheathed in fatty insulation. Glial cells provide support and nutrition to the neurons.

The neurons produce the electrical current. Their cell membranes are electrically excitable with the help of ion channels.

This is a brief overview. You can read more to get the detailed picture. Here's a good link: http://en.wikipedia.org/wiki/Brain

Answer 4

The brain is composed of neurons and glial cells. The neurons do the 'thinking', glial cells are mostly housekeeping and maintenance cells.

The 'electricity' that you are thinking of is expressed as 'potential' - a neuron will have more negatively charged ions within it's cell wall than outside. Once the potential reaches the cell wall's threshold potential, the cell wall depolarizes and allows ion exchange. The neuron 'fires' and the action is transmitted to the next neuron in line. Once that happens, the cell needs time to recoup itself before it is ready to act again.

Answer 5

Well it is mainly water and protein. The individual cells are called Neurons. The electrical current comes from an electro chemical reaction that is a result of our metabolism. In short, our bodies break down the food we eat and turn it into the energy our bodies use to function.

How that energy arranges itself in such a way as to cause us to be sentient remains a mystery.

Answer 6

Brain consists of fat and protein, the charge is carried through strands of tissue insulated by fatty deposits.

Answer 7

Interesting. It is was in then Gospel of Philip that humans created and even said that the gods ought to worship men, their creators.

Answer 8

98% water :D
chemical reactions