<h2>Axons </h2>
Explanation:
Axons cross from one side of the spinal cord to the other through the gray commisure
- Each arm or extension of the gray matter in the spinal cord is referred to as a horn
- Projecting towards the back of the spinal cord are the dorsal horns (or posterior horns)
- Projecting towards the front are the ventral horns (or anterior horns)
- In the thoracic and upper lumbar regions of the cord, an additional pair of side projections occur, which are called the lateral horns
- A narrow band of gray matter known as the gray commissure stretches across of the center of the spinal cord and connects the two sets of horns
- In the middle of the gray commissure is the central canal, which contains cerebral spinal fluid
Zoning laws establish the uses an area of land can be put to. Zoning's basic purpose is to equally divide the municipality into zones which includes residential, commercial and industrial zones. Separating and use of these zones should be reasonably equal.
Chemical factors: This is due to internal stimuli. Changes in the blood such as decrease in O2, increase in CO2 and decrease in PH cause impulse in the carotid artery which stimulates the respiratory centers in the medulla and cause breathing.
Mechanical factors: also called external stimuli. Compression of the fetal chest during delivery forces small amount of lung fluid out of the lungs. This increase in pressure in the chest draws air into the lungs.