1. Look At Your Body ... Brain and Nerves by Steve Parker

Copper Beech Books, Brookfield, Cunnecticut, USA

This is an excellent children's book giving a basic understanding of Brain and nervous system. The complex concepts are supplemented with beautiful illustrations. The following is the summary.

The Brain in the human body is formed as follows. About 4 weeks into conception, the nerve tissue on the back of embryo forms a tube. The front of this tube enlarges and develops into three bulges which develop into the main three sections of the brain, forebrain, midbrain, and hindbrain. The rear part of the tube develops into spinal cord.

Brain is stationed in the head of every human being and consists of mainly nerve cells for receiving, storing, analyzing and transmitting information for human body function. Nerve cells come in various form and shapes depending upon their local function. Human Brain weighs about 3 lbs. Humans have one of the highest brain to body weight ratio, at 1:50. In comparison, a chimpanzee is 1:120 and a cow is 1:1200.

In an unborn baby 1.25 million brain cells(nerve cells) are produced every minute until it is born at which it will have nearly 500 billion brain cells. After the age of 20 between 10,000 and 100,000 brain cells die each day. while we are learning new things, interconnections between neural cells are formed.

Brain tapers at its base into the spinal cord which runs through Vertebra, the backbones. The brain and spinal cord form the Central Nervous System(CNS). A network of smaller nerves branch from spinal cord and reach every part of the body. These nerves are called Peripheral Nervous System(PNS). Certain parts of brain, spinal cord and Peripheral nervous system, form another system called Autonomic Nervous System(ANS) which is responsible for the automatic functioning of organs (ex: Heart,Intestines etc.).

Our sensory organs in the body(eyes, ears, nose, tongue, skin) send signals to the brain directly and also through the spinal cord. And brain responds by sending action(motor) signals through the nervous system for taking proper action. Sometimes if the action has to be instantaneous (like when touching a hot plate etc.) the signal goes through a reflexive loop at the spinal cord and the danger averted by sending an action signal immediately before informing the brain. These are called body reflexes.

A nerve signal is a tiny pulse of electricity. It is produced by the quick movement of electrically charged chemical particles Sodium and Potassium in the cell and travels along its outer membrane(Skin). Signal transmission occurs by these tiny pulses going from one cell to other. The signal transmission junction between two nerve cells is called a synapse. In synapse a flood of Neurotransmitters are released and they move quickly and reach the Receptors at the signal receiving nerve cell. The signal jumps between cells and finally reaches its destination in the nervous system. Nerve signals travel quickly, about 330 feet(100 meters) per second.

A beautiful example of signal transmission is the False Start in running races. The starting gun sound has to reach the ear of the runner and should go to the brain and get response(run signal) to the leg muscles, which will take tenth of a second. If the runner responded quickly before tenth of a second, it is a False Start and flagged as such in the race.

Most of the Nerve disorders(Depression, Epilepsy, Parkinson's etc) come because of problems in Nerve signal generation or transmission.