Nervous System Organization

November 18-19, 2013

Nervous System Fun FactsWhich “fact” is false?1) All body functions are controlled and regulated by the

nervous system2) There are more neurons in the brain then there are

stars in the Milky Way galaxy3) The left side of the body is controlled by the right side

of the brain and vice-versa4) The brain reaches maturity at around 25 years of age.

The endocrine system also controls and regulates some body functions, especially metabolism, growth, and reproduction.

Nervous System FunctionsThe nervous system has three major functions:1) Sensory

input2) Integration3) Motor

output

Nervous System Functions1) Sensory input – the body gathers information, or stimuli, from the internal or external environment

Ex) seeing a bright light

Nervous System Functions2) Integration– the body processes information and makes a decision about what should be done

Example: “decision” to initiate flight – or- fight response

Nervous System Functions3) Motor Output– the body activates muscles or glands to effect a response.

Example: moving your arm to grab a chip

Nervous System FunctionsWhich function(s) are demonstrated in these examples?

You hear a buzzing sound.

You weigh the pros and cons of two different universities, and make a choice.

You move your leg

You touch a hot stove and jerk your hand back.

Sensory input

Motor output

integration

Sensory input, integration, motor output

Nervous System OrganizationThe nervous system can be organized by structure and by function.

Nervous System OrganizationStructurally, the nervous system is organized intoThe central nervous system, which consists of the brain and spinal cord, and which acts to integrate (interpret & issue instructions for) stimuliThe peripheral nervous system which consists of all the nerves outside the brain and spinal cord. These receive stimuli and effect responses in muscles

and glands.

Nervous System Organization

Nervous System OrganizationThe peripheral nervous system can be further divided into:1) Afferent or sensory neurons - bring stimuli -- affect the body by internal or external information

2) Efferent or motor neurons -- cause muscles or glands to respond -- effect a change / response Mneumonic: A comes before E

Nervous System OrganizationThe efferent / motor neurons can be further divided into:1) Somatic neurons - neurons that control skeletal muscles - mostly voluntary

2) Autonomic neurons -- neurons that control smooth and cardiac muscle and glands - involuntary

Nervous System OrganizationDetermine which parts of the nervous system are involved in these:

You hear a buzzing sound.

You weigh the pros and cons of two different universities, and make a choice.

You move your leg

You touch a hot stove and jerk your hand back.

Nervous System OrganizationDetermine which parts of the nervous system are involved in these:

You hear a buzzing sound.

You weigh the pros and cons of two different universities, and make a choice.

You move your leg

You touch a hot stove and jerk your hand back.

Afferent (peripheral)

Central nervous system

Central nervous system

1) Afferent (peripheral)2) Central nervous system3) somatic (efferent, peripheral)

Exit Ticket – Complete two vocab mini posters

Closure What were our objectives today and what are

your biggest take-aways?How does what we did today relate to our

unit objective?How does what we did today related to LP or

TOK?

Homework Complete neuroglia reading and worksheet, if

not yet doneRead chapter 7