The nervous system is a complex, highly coordinated network of tissues that communicate via electro chemical
signals. It is responsible for receiving and processing information in the body and is divided into two main branches:
the central nervous system
So far, researchers have discovered about 1520 different neurotransmitters, and new ones are still being identified.
The nervous system communicates accurately because there are so many neurotransmitters and because
neurotransmitters work only at matching
There are two kinds of cells in the nervous system: glial cells and neurons.Glial cells, which make up the support
structure of the nervous system, perform four functions:
Provide structural support to the neurons
To examine the brains functions, researchers have to study a working brain, which means they cant use cadavers.
Invasive studies, in which researchers actually put instruments into the brain, cant be done in humans, though they
can be done occasionally du
The brain is divided into three main parts: the hindbrain, the midbrain, and the forebrain.
The hindbrain is composed of the medulla, the pons, and the cerebellum. Themedulla lies next to the spinal cord
and controls functions outside consci
The endocrine system, made up of hormone-secreting glands, also affects communication inside the
body. Hormones are chemicals that help to regulate bodily functions. The glands produce hormones and dump them
into the bloodstream, through which the hormone
Consciousness is the awareness we have of ourselves and our environment. Different states of consciousness are
associated with different patterns of brain waves. Brain waves are tracings of electrical activity that is going on in the
brain. Scientists rec
Consciousness is the awareness people have of themselves and the environment around them.
The level and state of consciousness vary. Different states of consciousness are associated with different
brain wave patterns.Brain waves are tracin
Cognition, or thinking, involves mental activities such as understanding, problem solving, and decision making.
Cognition also makes creativity possible.
The Building Blocks of Cognition
When humans think, they manipulate mental representations of objects
Cognitive development refers to the change in childrens patterns of thinking as they grow older.
Jean Piagets Stage Theory
The scientist best known for research on cognitive development isJean Piaget (see pages 7275), who proposed
that childrens thinking
Today, researchers generally agree that heredity and environment have an interactive influence on intelligence. Many
researchers believe that there is areaction range to IQ, which refers to the limits placed on IQ by heredity. Heredity
places an upper and