Download The Nervous System Period 1 - Mercer Island School District

The Nervous System
Period 1
By Griffin, Paige, and Claire
Overview
Function
Receptors
Central Nervous System
Peripheral Nervous System
Main Organs/Cells
Homeostasis
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
Types of receptors
Touch - pain, pressure, heat, cold
Sight - photoreceptors
Smell - chemical receptors
Taste - chemical receptors
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)
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
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
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
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
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
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
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)
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.
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.
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
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
Sources
http://www.nsta.org/publications/interactive/nerves/basics/ouch.html
https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/sensation-andperception-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
Sources
https://prezi.com/ft96fr9kjdjd/how-the-nervous-interacts-with-other-systems-inyour-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/