 The nervous system of the human being is responsible for sending, receiving, and processing nerve impulses throughout the body. This series of articles explains the nervous system for the more technically minded individual.
|
Sub-Categories:
Nerves of the Body
Articles:
What is the Nervous System?
submitted by Dr. Gary Farr 6/24/2002
The nervous system of the human being is responsible for sending, receiving, and processing nerve impulses throughout the body. All the organs and muscles inside your body rely upon these nerve impulses to function. It could be considered as the master control unit inside your body.
Emotion & Behavior
submitted by Dr. Gary Farr 6/24/2002
In order to carry out the correct behaviour—that is to say, correct in relation to the survival of the individual and the group—humans and other higher animals developed innate drives, desires, and emotions, and the ability to remember and learn. These fundamental features of living depend on the entire brain, yet there is one part of the brain that organizes metabolism, growth, sexual differentiation, and the desires and drives necessary to achieve these aspects of life. This is the hypothalamus and a region in front of it comprising the septal and preoptic areas.
Functions of the Nervous System
submitted by Dr. Gary Farr 6/24/2002
The human nervous system differs from that of other mammals chiefly in the great enlargement and elaboration of the cerebral hemispheres. Much of what is known of the function of the brain is derived from observations of the effects of disease or by analogy with the results of experimentation on animals, particularly the monkey. Such sources of information are clearly inadequate for the elucidation of the nervous activity underlying many properties of the human brain—particularly speech and mental processes. It is not surprising, therefore, that knowledge of the functions of this uniquely complex system, although rapidly expanding, is far from complete.
Nerves - The Functional Unit of the Nervous System
submitted by Dr. Gary Farr 6/24/2002
The body is made up of trillions of cells. Cells of the nervous system, called neurons, are specialized to carry "messages" through an electrochemical process. Just by itself, the human brain has about 1 trillion neurons.
Pain
submitted by Dr. Gary Farr 6/24/2002
There have always been two theories of the sensation of pain, a quantitative or intensity theory and a stimulus-specific theory. According to the former, pain results from excessive stimulation of every kind: e.g., excessive heat or cold, excessive damage to the tissues. In contrast, the quantitative theory seems to apply to the viscera, where afferent nerve fibers used in reflex organization also report events giving rise to pain. In the heart, for example, the same nerve fibers are excited by mechanical stimulation as are excited by chemical substances formed in the body that cause pain.
The Autonomic Nervous System
submitted by Dr. Gary Farr 6/24/2002
The autonomic nervous system is a part of the peripheral nervous system that functions to regulate the basic visceral (organ) processes needed for the maintenance of normal bodily functions. It operates independently of voluntary control, although certain events, such as emotional stress, fear, sexual excitement, and alterations in the sleep-wakefulness cycle, change the level of autonomic activity.
The Brain
submitted by Dr. Gary Farr 6/24/2002
The nervous system of the human being is responsible for sending, receiving, and processing nerve impulses throughout the body. All the organs and muscles inside your body rely upon these nerve impulses to function. It could be considered as the master control unit inside your body.
The Central Nervous System
submitted by Dr. Gary Farr 6/24/2002
The central nervous system is divided into two major parts: the brain and the spinal cord. In the average adult human, the brain weighs about 3 pounds. The brain contains about 100 billion nerve cells (neurons) and trillons of "support cells" called glia. The spinal cord is about 43 cm long in adult women and 45 cm long in adult men and weighs about 35-40 gm.
The Cranial Nerves
submitted by Dr. Gary Farr 6/24/2002
Cranial nerve I is the olfactory nerve, the nerve responsilbe for the sense of smell. Cranial nerve II is the optic nerve, the nerve responsible for sight. Both are discussed.
The Hypothalamus
submitted by Dr. Gary Farr 7/2/2002
The hypothalamus is an integral part of the substance of the brain. A small cone-shaped structure, it projects downward, ending in the pituitary (infundibular) stalk, a tubular connection to the pituitary gland. The round bony cavity containing the pituitary gland is called the sella turcica. The posterior portion of the hypothalamus, called the median eminence, contains many neurosecretory cells.
The Meninges
submitted by Dr. Gary Farr 6/24/2002
The meninges, (singular meninx), are three membranous envelopes—the pia mater, the arachnoid, and the dura mater—that surround the brain and spinal cord. Cerebrospinal fluid fills the ventricles of the brain and the space between the pia mater and the arachnoid. The chief function of meninges and cerebrospinal fluid is to protect the central nervous system.
The Peripheral Nervous System
submitted by Dr. Gary Farr 6/24/2002
The peripheral nervous system is a channel for the relay of sensory and motor impulses between the central nervous system on the one hand and the body surface, skeletal muscles, and internal organs on the other hand. It is composed of (1) spinal nerves, (2) cranial nerves, and (3) certain parts of the autonomic nervous system.
The Spinal Cord
submitted by Dr. Gary Farr 6/24/2002
The spinal cord is an elongated cylindrical structure, about 45 centimetres (18 inches) long, that extends from the medulla oblongata of the hindbrain to a level between the first and second lumbar vertebrae of the backbone.
Related News:
|
