CHS AP Psychology

Unit 3: Biological Psychology

Essential Task 3-5b:Describe the subdivisions and functions of the peripheral nervous system:A. Somatic Nervous SystemB. Autonomic Nervous System

– i. Sympathetic Nervous System (Fight or Flight)– ii. Parasympathetic Nervous System (Rest and Digest)

http://spinacare.files.wordpress.com/2007/02/bigstockphoto_heart_beat_1093363.jpg

The Central Nervous System

• The Brain• The Spinal Cord

The Spinal Cord

• Complex cable of nerves that connects brain to rest of the body

• Carries motor impulses from the brain to internal organs and muscles

• Carries sensory information from extremities and internal organs to the brain

• 400,000 people a year in US either partial or complete paralysis.

The Spinal Cord

• The spinal cord controls some protective reflex movements without any input from the brain

The Somatic Nervous System

• Consists of neurons that communicate between the body and the brain

• Motor Neurons– Neurons that carry messages from the

spinal cord (through interneurons) or brain to muscles and glands

The Autonomic Nervous System

• Sympathetic division– Most active when you

are angry, afraid, or aroused

– Increases heart rate and breathing

– Stops digestion– “Fight-or-flight”

SNS = Evolutionary Byproduct

What “fear” looks like…(Taken in a Haunted House)

A Sympathetic Nervous System (SNS) Response

Hold me!

Congo line of fear

Even Flannel Bros have an SNS response

The “I’m not really here to protect you;

I just happen to be in front” response.

Fight, Flight and “Freeze”?

The pupils don’t just dilate for some people. The eyes widen, too!

The Autonomic Nervous System

• Parasympathetic division– Calms body– Produces effects

opposite to those of the sympathetic division

– Reduces heart rate and breathing

– Restores digestion– “Rest and Digest”

The Hypothalamus Has Central Control of the ANS• When someone experiences a stressful event, the

amygdala, an area of the brain that contributes to emotional processing, sends a distress signal to the hypothalamus. – This area of the brain functions like a command center,

communicating with the rest of the body through the nervous system so that the person has the energy to fight or flee.

• The hypothalamus is involved in the coordination of ANS responses– One section of the hypothalamus seems to control

many of the "fight or flight" responses; another section favors "rest and digest" activities