Download Document

A.
Skin system
1.
Skin temperature: During stress, blood is directed away from
the extremities so that it can be redirected toward the vital
organs.
a.
Therefore, when stressed, our suface skin temperature
decreases
b.
Norepinephrine constricts the blood vessels
(vasoconstriction) of the arms and legs so our fingers
and toes feel colder
2.
Galvanic Skin Response (GSR): a measure of the degree of
electrical
conductance of our skin
a.
b.
c.
d.
When we’re stressed, we perspire
The increased perspiration, even if imperceptible,
increases our skin’s electrical conductance
This conductance is measured by a GSR and is a major
component of a lie detector (along with respirations
and heart rate)
A lie detector assumes that a person would be stressed
by lying. If a person has no conscience and is not
stressed, they could pass a lie detector test. If a person
is overly anxious or nervous at having to take a lie
detector test, they could fail even if telling the truth
DEMONSTRATION: Using the GSR as a lie detector. One person will be asked
questions about themselves. They will then be told to lie about something.
Questions will be repeated until the class can determine what thing the person is
lying about.
QUESTION: Based on the demonstration, what do you think about the validity of a
lie detector test for use in court?
II.
Muscles
1.
2.
They allow us to move and respond to the environment
Muscles respond to stress (through alternatingly contracting
and relaxing) and also provide feedback to the rest of our
body regarding how tense we are
EXERCISE: Turn off lights. Brief progressive muscle relaxation. Rate your muscular
tension on a scale from 1 to 10 (1 is not tense, 10 is as tense as you can be). Try
to determine which muscles are the most and least tense. Start at toes, work up.
When finished, rate tension. Which muscles are most and least tense? Rate
tension.
QUESTION: Why does this exercise seem to lower tension? What mechanisms
are working?
3.
4.
Muscles contract (or shorten) when stimulated; this shortening
causes tension
Two types of muscles
a.
b.
5.
When contracting, muscles also affect blood vessels
a.
b.
6.
Skeletal muscles contract and move bones
Smooth muscles contract and control internal organs
Pain can develop when a muscle is chronically
contracted because it is affecting the amount of blood
to the tissues
Also, a chronically contracted muscle puts pressure on
the joint, ligaments, tendons, overexerting these
Muscles contract both subconciously and voluntarily
QUESTION: Examples of subconscious muscle contractions in stress responses?
QUESTION: Examples of voluntary muscle contractions in stress responses?
a.
b.
c.
d.
In voluntary contractions, the motor cortex is involved
The brain decides an action and directs the body to
move in a particular way
Excitatory neurotransmitters are released and the
action potentials begin in the motor cortex and
continue until that muscle contracts
We have a sense called the proprioceptive sense
which provides feedback about our where our bodies
are in space
(1)
(2)
(3)
This sense relies on feedback from our muscles
back to our brain so that we can interpret where
we are in space
Thus, the muscular contraction is important
information for helping us make this
determination
Without it, we couldn’t do coordinated motor
movements
e.
Our brains are involved in another way as well
(1)
(2)
We memorize or learn certain ways of responding
so that we can act in ways that appear
subconcious or physical
We don’t have to consciously think about how to
run because we have learned engrams for this
(learned patterns of muscle movements), yet a 1
year old hasn’t learned these patterns yet.
QUESTION: Let=s break down running into each muscular contraction. How
many are involved? How complex is this behavior? What about fighting (i.e.,
the fight or flight response)? How many muscular contractions are involved
then?
(3)
f.
The engrams allow us to respond quickly in
response to threats or perceived threats and our
endocrine system, once engaged, allow us to
respond efficiently
Different tracts
(1)
(2)
(3)
Pyramidal tract: sends neural impulses from the
motor cortex to the muscles by the spinal cord
Extrapyramidal motor system: send signals from
the hypothalamus and upper limbic area (the
emotional center) to the muscles
Both of these can result in muscle contractions
which are specific (i.e., in response to a particular
threat) or nonspecific (i.e., generalized muscular
tension)--some people have greater resting
muscle tension than others and this puts a
greater strain on the system