The central nervous system is divided into two parts: the brain and the spinal cord. The average adult human brain weighs 1.3 to 1.4 kg (approximately 3 pounds). The brain contains about 100 billion nerve cells 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 grams. The vertebral column, the collection of bones (back bone) that houses the spinal cord, is about 70 cm long. Therefore, the spinal cord is much shorter than the vertebral column.
The peripheral nervous system is divided into two major parts: the somatic nervous system and the autonomic nervous system.
The following table shows how the nervous system can be divided. The bottom row of the table contains the names of specific areas within the brain.
Subscriure's a:
Comentaris del missatge (Atom)
Cap comentari:
Publica un comentari a l'entrada