Structure, Function,&

Information Processing

(Gather & synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories.) 08-LS1-8

Target 1 a – I can identify the structure and function of motor neuron, sensory neuron, and interneuron.

Target 1 b – I can draw a model of motor neuron, sensory neuron, and interneuron.

Humans versus Simple OrganismsSimple organisms like a flat worm or planarian the nervous system is spread out and disorganized.

In more complex animals the nervous system becomes more complex and the tissue that makes up the nervous system is concentrated in the head.

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=3zbR1kFv2mqU5M&tbnid=sX6Mt1YjqYrDYM:&ved=0CAQQjB0&url=http%3A%2F%2Fwww.goodpsych.com%2Fstress-psychology%2F&ei=ZZ83UtW6EcqF2QX0sIGgCg&bvm=bv.52164340,d.b2I&psig=AFQjCNEPshHl55Mj0lYzOZ-dlRcKL043Qw&ust=1379463371974851

More Complex organisms have highly developed sense organs like…..

The planarian has eye spots which help the organism detect light.

The fruit fly has multiple eyes to help it detect motion and some colors

http://www.microscopyu.com

The human auditory nerve detects vibrations that is turned into a signal in our brain recognizes as different pitches and frequencies.

Larger complex brains have different regions that are programed for different purposes.

http://keepingkidssafenow.info/anatomy/memory-part-of-the-brain/

What are neural networks? • Neural Networks are ………….

Groups of select neurons that are connected with one another to process information & create activities by sending messages throughout our body.– Part of our nervous system

* Brain * sensory nerves* Spinal cord * motor nerves

– Types of neurons ………….• Sensory neurons• Motor neurons• Interneurons

What are neurons?

Neuron Cell Body – it is the factory of the neuron because it produces proteins and energy that is are transferred to other parts of the nerve cell.

http://facstaff.bloomu.edu/jhranitz/Courses/APHNT/Laboratory%20Pictures.htm

Dendrites– the finger-like projections that surround the cell body. They receive electrical signals and relay the signals to the cell body.

Axon – is like a highway going AWAY from the cell body and dendrites to send signals to the synapse. It’s covered in a myelin sheath that insulates the axon which transmits electrical impulses. The speed of the impulse varies depending on the thickness of the myelin sheath.

http://news.emory.edu/stories/2012/07/new_gene_linked_with_familial_ALS_critical_for_axon_growth/

http://www.cerebromente.org.br/n07/fundamentos/neuron/parts_i.htm

Synapse – is an area between a dendrite and axon terminal where electrical and chemical signals cross from one neuron to another neuron until it reaches the brain.

Axon Terminal

http://faculty.washington.edu/chudler/synapse.html

Why are neural networks important? • Determine how we behave as individuals–Our emotions–Our ability to think and store information

(memories)–Program our movements (how we type,

play sports, our vision and hearing)–Control Important Body Functions• Body temperature• blood pressure

Types of Neurons

Sensory NeuronTypical Neuron

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Sensory Neurons – “Spy for the Brain”

Function

• Detects what is happening outside & inside the body using the 5 senses.• Reports the information to the network of

interneurons through an electrical impulse.

How does it collect the information?• By using our senses which react to a

stimulus. (ex: eyes, ears, skin)

•An initial (beginning) event that causes the neuron to activate• Examples• – a cold breeze blowing across

your arm• - someone using their fingernails

on the chalkboard• - some cooking fried chicken

Stimulus Defined

Interneuron

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=hXxjqddBa8RbUM&tbnid=_ZWnrMttHkqOHM:&ved=0CAQQjB0&url=http%3A%2F%2Fhealth.howstuffworks.com%2Fhuman-body%2Fsystems%2Fnervous-system%2Fbrain-pictures.htm&ei=o2A7UrfjNJLK9QT18YHACg&bvm=bv.52288139,d.eWU&psig=AFQjCNGDzp3WxIEC5gIGVorzC8QxY9VVAA&ust=1379709333478858

Interneurons – “Connector”

Function

•Receives information about the outside environment or inside state of the body from sensory neurons.•Activates motor neurons.

Motor Neuron

Motor Neurons – “Interstate”

Function

•Receives information from interneurons•Transfers information to

“Effector Systems” like muscles, glands, & internal organs.

• The response or action that occurs after a stimulus (effect)• Examples:• - you shiver because a cold breeze blew

across your arm• - you get Goosebumps because

someone scratched their fingernails across the chalkboard• - your mouth begins to water because

you smell fried chicken cooking

Response (Reflexes) Defined

• Autonomic• Acts on its own without you consciously

trying to control it.• Examples:• Heart rate (blood pressure)changes as

your body changes to different conditions such as – your heart beats faster after you have just walked from one classroom to another. You don’t consciously think about raising your heart rate.

Response (Reflexes) Types

Experiment Time

Autonomic Experiment ExplanationThe reason your heart rate typically increases when you stand up is due to the fact that blood tends to settle in your legs and there is less blood in your heart. This causes your heart to work harder to pump more blood to increase your blood pressure until it reaches its normal level again. This is an autonomic reflex.