HTHSCI 1H06 Chapter Notes - Chapter 12: Enteric Nervous System, Somatic Nervous System, Foramen Magnum

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Peter Helli

Document Summary

The brain is the part of the cns that is located in the skull and contains about 85 billion neurons. The spinal cord is connected to the brain through the foramen magnum of the occipital bone and is encircled by the bones of the vertebral column. The spinal cord contains about 100 million neurons. Nerve: is a bundle of hundreds to thousands of axons plus associated connective tissue include nerves, ganglia, enteric plexuses, and sensory receptors. and blood vessels that lie outside the brain and spina cord. Twelve pairs of cranial nerves emerge from the brain. Thirty-one pairs of spinal nerves emerge from the spinal cord. Ganglia: are small masses of nervous tissue, consisting primarily of neuron cell bodies that are located outside of the brain and spinal cord. Enteric plexuses: are extensive networks of neurons located in the walls of organs of the gastrointestinal tract. The neurons of these plexuses help regulate the digestive system.