Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 9, 2025
*The Problem of Seeing.*—What we call seeing is vastly more than the stimulation of the brain through the action of light upon afferent neurons. It is the perceiving of all the different things that make up our surroundings. If one looks toward the clear sky, he receives a sensation of light, but sees no object.
C. Section of a nerve trunk. 1. Epineurium consisting chiefly of connective tissue. 2. Bundles of nerve fibers. 3. Covering of fiber bundle, or perineurium. 4. Small artery and vein. The side-by-side arrangement of the neurons shows clearly the structure of the ganglia and nerves.
Compare the skeleton outline of the nervous system with the bony skeleton. Sketch outlines of mon-axonic and di-axonic neurons. Give two differences between the neurons and the other cells of the body. Describe the two general methods of connecting neurons in the body. What purpose is accomplished by each method? Name and locate the principal divisions of the nervous system.
They are acted upon by external stimuli, while their impulses in turn act on the neurons in the spinal cord. This, the intermediate division, may be composed of mon-axonic neurons, or it may consist of branches from the afferent neurons. From the central nervous system to the muscles. This, the efferent division, is made up of mon-axonic neurons.
The dendrites serve two purposes: first, they extend the surface of the cell-body, thereby enabling it to absorb a greater amount of nourishment from the surrounding lymph; second, they act as receivers of stimuli from other neurons. The same impulse does not pass from one neuron to another. The special function of the axon is to transmit the impulse.
Sorrow for him, she told herself, was a brief misfiring of neurons in an awkward situation that brought on a second of a brief hallucination and an emotional barricade that she now had to scurry around. Gabriele ate a piece of cold toast abandoned near the bacon. She was hungry so she ate. The fact that it was cold showed his hostility toward her.
It was one of his last Halloweens as a boy and perhaps his last time dressed for trick or treat and it had come to this. With the car towed off to the mechanic, she hated him for a week and then it slowly abated, lost and tangled within new neurons, new electronic circuits with thoughts successfully attempting to understand his bitterness, and with new emphasis to forgive and forget.
The steps in the production of any special sensation naturally involve the following parts: 1. A sense organ where the terminations of the neurons are acted upon by the stimulus. A chain of neurons which connect the sense organ with the brain. The part of the cerebrum which produces the sensation.
Control of Arteries.—Changes in the rate and force of the heart’s contractions can be made to correspond only to the general needs of the body. When the blood supply to a particular organ is to be increased or diminished, this is accomplished through the muscular coat in the arteries. These, like the controlling neurons of the heart, have their cell-bodies in the bulb.
*Structure of the Axon.*—The axon, or nerve fiber, has practically the same structure in both classes of neurons, being composed in most cases of three distinct parts. The axis cylinder is present in all axons and is the part essential to their work. It may be considered as an extension of the protoplasm from the cell-body.
Word Of The Day
Others Looking