The spinal cord behaves like an information superhighway, speeding signals from the brain to the PNS and vice versa. Like the muscular system, the PNS, consisting of all the roads that ultimately lead to the superhighway, has a dual function. One part is somatic, meaning under conscious control, and the other is autonomic, or outside of conscious control. Nerves work together with muscles your conscious mind relays this command to your CNS, which translates it into electrical impulses. These are then channeled through the somatic part of your PNS to the nerves responsible for controlling the necessary muscles. When the messages arrive, a chemical (acetylcholine) is released from the nerve endings, stimulating the membranes of muscle fibers and causing them to contract. This takes about 1 millisecond to happen. Normally, your conscious mind is unable to speed up or slow down your heart
The spinal cord behaves like an information superhighway, speeding signals from the brain to the PNS and vice versa. Like the muscular system, the PNS, consisting of all the roads that ultimately lead to the superhighway, has a dual function. One part is somatic, meaning under conscious control, and the other is autonomic, or outside of conscious control. Nerves work together with muscles your conscious mind relays this command to your CNS, which translates it into electrical impulses. These are then channeled through the somatic part of your PNS to the nerves responsible for controlling the necessary muscles. When the messages arrive, a chemical (acetylcholine) is released from the nerve endings, stimulating the membranes of muscle fibers and causing them to contract. This takes about 1 millisecond to happen. Normally, your conscious mind is unable to speed up or slow down your heart