The nervous system makes it possible for animals to know and react to the environment around them. A change or event that evokes a specific functional reaction in an organ or tissue is a stimulus. There can either be an internal or an external stimulus. Internal stimulus being something like hunger or pain, while external is more along the lines of a sound or an odor. The nervous system interprets stimuli and orders other organ systems to respond. The nervous system does so through using sensory receptors. Sensory receptors are made up of sensory nerve cells and support cells.
There are millions of nerve cells in the human body that control just about every move you make, the human brain alone carries about 100 billion neurons. Every neuron …show more content…
The main division is between the central nervous system and the peripheral nervous system. The central nervous system (CNS) contains the brain and spinal cord, while the peripheral nervous system (PNS) carries information between the CNS and other organs. The PNS consists of 12 pairs of cranial nerves that extend from the brain into the head and upper body, in addition to 31 pairs of spinal nerves that branch out from the spinal cord throughout the entire body. The PNS contains of all of the nerve tissue except the brain and spinal cord. The peripheral nervous system has two main divisions; sensory and motor. The sensory division helps maintain homeostasis by coordinating the functions of internal organs and providing the CNS with sensory information. The motor division enables an organism to respond to its environment by stimulating activities of glands and muscle contraction. The motor division includes the autonomic system and the somatic nervous system. The somatic system is in charge of skeletal muscle contraction, which is normally voluntary. Whereas the autonomic nervous system is responsible for involuntary responses. For example, changes in the activities of glands or the digestive system. These systems often work together, like when you’re cold. Your brain signals to your autonomic nervous system to constrict surface blood vessels in your skin. Meanwhile, your brain is also signalling to your somatic nervous system to stimulate your skeletal muscles, which cause you to shiver. Inside of the autonomic nervous system, there is the sympathetic division and the parasympathetic system. The sympathetic system prepares an animal for quick action and also reduces the activity of the digestive system and stimulates the heart to beat faster. The parasympathetic system does quite the opposite. It reduces an animal’s readiness for
There are millions of nerve cells in the human body that control just about every move you make, the human brain alone carries about 100 billion neurons. Every neuron …show more content…
The main division is between the central nervous system and the peripheral nervous system. The central nervous system (CNS) contains the brain and spinal cord, while the peripheral nervous system (PNS) carries information between the CNS and other organs. The PNS consists of 12 pairs of cranial nerves that extend from the brain into the head and upper body, in addition to 31 pairs of spinal nerves that branch out from the spinal cord throughout the entire body. The PNS contains of all of the nerve tissue except the brain and spinal cord. The peripheral nervous system has two main divisions; sensory and motor. The sensory division helps maintain homeostasis by coordinating the functions of internal organs and providing the CNS with sensory information. The motor division enables an organism to respond to its environment by stimulating activities of glands and muscle contraction. The motor division includes the autonomic system and the somatic nervous system. The somatic system is in charge of skeletal muscle contraction, which is normally voluntary. Whereas the autonomic nervous system is responsible for involuntary responses. For example, changes in the activities of glands or the digestive system. These systems often work together, like when you’re cold. Your brain signals to your autonomic nervous system to constrict surface blood vessels in your skin. Meanwhile, your brain is also signalling to your somatic nervous system to stimulate your skeletal muscles, which cause you to shiver. Inside of the autonomic nervous system, there is the sympathetic division and the parasympathetic system. The sympathetic system prepares an animal for quick action and also reduces the activity of the digestive system and stimulates the heart to beat faster. The parasympathetic system does quite the opposite. It reduces an animal’s readiness for