1. The Nervous System Period 1 By Griffin, Paige, and Claire

2. Overview Function Receptors Central Nervous System Peripheral Nervous System Main Organs/Cells Homeostasis Interaction with other systems Disorders/Diseases

3. Function The nervous system is responsible for coordinating all of the body’s activities. It controls not only the maintenance of normal functions, but also the body’s ability to cope with emergency situations. Three general functions: -Sensory Function -Interpretative Function -Motor Function

4. Types of receptors Touch - pain, pressure, heat, cold Sight - photoreceptors Smell - chemical receptors Taste - chemical receptors

5. Touch receptors Touch receptors function by receiving chemical signals from surrounding cells, and through dendrites, transform the chemical signal into an electrical one. Pain - when cells are damaged, they release a chemical that causes a change in the membranes of dendrites. (Called nociceptors) Heat/Cold - when skin is rubbed to warm it up, it stimulates receptors. The electrical signals formed travel the same path as those from pain receptors and can help to mask pain. (Called thermoceptors) Pressure - when texture, pressure, or changes in environment occur, pressure receptors release electrical signals that travel to the brain. (Called mechanoreception)

7. Sight receptors Cells in the retina that respond to light Light photons are absorbed and then contribute to the electrical signal sent to the brain. Called photoreceptors

8. Taste and Smell Receptors Smell and taste receptors converge so they can affect each other. Flavor is a combination of both smell and taste Taste - taste buds sense chemical changes to send electric signals Smell - olfactory bulbs located in the back of the nasal cavity detect chemical changes sending electrical signals to the brain

9. Central Nervous System Primary command center for the body Comprised of the brain and spinal cord The brain is the final destination point for information gathered by the nervous system

10. Peripheral Nervous System Consists of a network of nerves that connects the rest of the body to the central nervous system Nerves branch from either the brain or the spinal cord Each nerve is connected to a particular area of the torso or limbs and is responsible for communication to and from those regions

11. Main Organs/Cells Nervous Tissue: -Neurons communicate within the body by transmitting electrochemical systems -Neuroglia acts as the “helper” cells of the nervous system and they protect, feed, and insulate the neuron

12. Main Organs/Cells Brain: -The 100 billion neurons of the brain form the main control center of the body and it controls higher mental functions as well as lower body functions Spinal Cord: -The white matter of the spinal cord serves as the main conduit of nerve signals to the body from the brain -The grey matter of the spinal cord integrates reflexes to stimuli

13. Main Organs/Cells Nerves: -Act as information highways to carry signals between the brain and spinal cord and rest of the body -Different types of nerves (Afferent, Efferent, Mixed, Cranial, and Spinal Nerves)

14. Stimulus to Response When a stimulus is received by a sensory neuron, the impulse (or message) is carried through fibrous extensions called dendrites to the cell body. An impulse begins when a neuron is stimulated by another neuron or by a stimulus in the environment. The cell membranes begin to change the flow of ions and a reversal of charges, the action potential, results.

15. Homeostasis The nervous system maintains homeostasis by controlling and regulating the other parts of the body. A deviation from a normal set point acts as a stimulus to the receptor, which sends nerve impulses to a regulating center in the brain. The brain directs an effector to act in such a way that an adaptive response takes place.

16. Interaction With Other Systems Digestive System: Sends messages from the brain to the muscles in the digestive system for eating and elimination of waste food. Circulatory System: Baroreceptors send the brain information on the blood pressure. The brain regulates the heart rate using the nerves. Respiratory System: The brain monitors the respiratory volume and blood gas levels. The brain regulates respiratory rates. Endocrine System: Hormones give information to the brain to affect neural processing

17. Harmful Diseases/Disorders Multiple Sclerosis: Damaged nerves prevent signals from traveling along them Meningitis: Causes an inflammation of the membranes surrounding the brain and spinal cord

18. Sources http://www.nsta.org/publications/interactive/nerves/basics/ouch.html https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-and- perception-5/sensory-processes-38/somatosensation-pressure-temperature-and-pain-165-12700/ http://www.healthline.com/human-body-maps/nervous-system http://www.britannica.com/science/photoreception/Structure-and-function-of-photoreceptors http://www.innerbody.com/image/nervov.html http://www.brainfacts.org/sensing-thinking-behaving/senses-and-perception/articles/2012/taste-and-smell/ http://www.mhhe.com/biosci/genbio/maderbiology/supp/homeo.html

19. Sources https://prezi.com/ft96fr9kjdjd/how-the-nervous-interacts-with-other-systems-in- your-body/ http://lrrpublic.cli.det.nsw.edu.au/lrrSecure/Sites/LRRView/7700/documents/5657/ 5657/5657_05.htm http://www.e-missions.net/cybersurgeons/?/nerv_teacher/