Lecture 6: Chapter 7 – The Autonomic Nervous System and Hormones Flashcards
The autonomic nervous system is a component of the _____ _____ _____ that regulates ____ ____ ______?
The autonomic nervous system is a component of the peripheral nervous system that regulates involuntary physiological processes
The autonomic nervous system connects to organs such as the?
The heart, lungs, stomach, intestines, genitals, and smooth muscle around arteries
The autonomic nervous system consists of two chains of neurons alongside the spinal cord:
- Sympathetic system: “fight or flight” system
- Walter Cannon (1915) determined that the sympathetic nervous system prepares the body for vigorous/stressful activity - Parasympathetic system: “rest and digest” system
- Activates to relax and repair body after periods of stress
List the 6 short-term impacts from the SNS to engage in vigorous activity
- Increases blood flow to brain and muscles via vasodilation of arteries
- Relaxes and expands bronchioles (sacs in lungs) to increase oxygen intake
- Accelerates heartbeat to improve transfer of oxygen to tissues
- Dilates pupils in order for the retina to take in more light
- Also indicates sexual interest
- Increases sweating to cool down body from increased heat
- Piloerection: making the body’s hairs stand up on end
- Makes animal look larger when frightened,
evolutionary relic in humans
- Makes animal look larger when frightened,
List the 3 long-term impacts from the SNS to engage in vigorous activity
- Secretion of adrenaline, noradrenaline, and cortisol to engage body’s stress response
- Stimulates glucose production and release from liver to supply energy
- Stimulates overall cellular metabolism and breakdown of fats in body
List the 5 mechanisms of the SNS to decrease resting/relaxing behaviour
- Constricts blood flow to hands, feet, and skin via vasoconstriction of arteries
2 Inhibits peristalsis (intestine pulsing) and secretion via vasoconstriction of arteries - Inhibits salivation, leading to dry-mouth feeling
- Inhibits bladder contraction, preventing bladder emptying
- Stimulates orgasm (climaxes/ends sexual activity)
Sympathetic nerves travel ____ each other for long distances along the spinal cord, and synapses connecting to different organs are typically ____ ____
Sympathetic nerves travel alongside each other for long distances along the spinal cord, and synapses connecting to different organs are typically clustered together
Initially, researchers believed that sympathetic branch acted in “____” with each other, resulting in an ______ _____
Researchers believed that sympathetic branch acted in “sympathy” with each other, resulting in an all-or-none response
It is now understood that activation of the sympathetic branch is more _____ with different combinations of _______ and ______ _____
Now understood activation is more differentiated with different combinations of neurotransmitters and receptor subtypes
In contrast to sympathetic nerves, parasympathetic nerves ___ __ and head for different organs closer to the spinal cord. Thus?
In contrast to sympathetic nerves, parasympathetic nerves split off and head for different organs closer to the spinal cord. Thus, stimuli that activate one part of system may or may not activate other parts
List the 9 functions of the parasympathetic nervous system (rest and digest)
- Constricts pupils to conserve energy
- Stimulates flow of saliva to aid in digestion
- In cats and dogs, reflects increased parasympathetic stimulation associated with contentment - Constricts and shrinks bronchioles
- Slows heartbeat
- Stimulates peristalsis and secretion of digestive chemicals (e.g. bile) in GI tract
- Insulin secreted to facilitate the storage of energy in fatty tissues and in the liver
- Contracts bladder, allows bladder emptying
- Does not affect blood vessels directly, but less sympathetic activity will send more blood to digestive system, less to muscles/brain
- Big meals make one feel lethargic when exercising, and sleepy (less blood to brain) - Promotes body conditions favourable for sexual activity
- Increases blood vessel dilatation in genitals of males and females, facilitating sexual arousal
Explain the 1st role of the parasympathetic nervous system in emotion
A certain degree of calming is valuable for social relationships and for some positive emotions (Porges, 1997)
Explain the 2nd role of the parasympathetic nervous system in emotion
People with higher resting parasympathetic activation:
1. Tend to be better than average at regulating their emotions (Butler, Wilhelm & Gross, 2006)
2. Report more positive affect in their daily lives (Bhattacharyya et al., 2008)
Explain the 3rd role of the parasympathetic nervous system in emotion
Heart rate predicts amount of compassion people feel and show when someone else is suffering (Stellar, Cohen, Oveis & Keltner, 2015)
1. Moderately slowing your heart rate helps you focus on others and stop worrying about your own problems
2. Too much calming causes people to stop worrying about others as well
How do the sympathetic and parasympathetic systems work together?
Both work in concert to regulate bodily activity (similar to pedal and brake in a car)
Describe how the sympathetic and parasympathetic systems work together in the rabbit example
- After hearing a sudden noise, rabbit’s sympathetic NS will dilate pupils, and slightly increases sweating, and parasympathetic NS will decrease heart rate
- Helps to focus attention on outside environment
Describe how the sympathetic and parasympathetic systems work together in the human example
Humans read a list of objects and evaluated their usefulness in life-or-death situations (thinking of threats, but not yet doing anything about it)
Finding: increased attention being paid to words on the list results in increased probability of remembering words on list
Describe how the sympathetic and parasympathetic systems work together with respect to the nausea example
During nausea, sympathetic NS decreases stomach contractions and induces gagging, while parasympathetic NS stimulates intestines and salivary glands, while slowing heart rate
Describe the methods of Löw, Lang, Smith & Bradley (2008) study on how the sympathetic and parasympathetic systems work together
- Had participants play video game where they have an opportunity to win some money, and sometimes face the threat of losing it
- As gun approaches you and gets larger, you have an increased chance to lose money, unless you react quickly enough when signal appears
Describe the two findings of Löw, Lang, Smith & Bradley (2008) study on how the sympathetic and parasympathetic systems work together
- When gun is small and distant, heart rate decreases (PSN activated to increase attention)
- When gun grows larger, heart rate increases for vigorous response (SNS activated)
Define the endocrine system
Hormones in the body and the glands that produce them
Define Hormones
Chemicals produced and released by glands in one part of your body and carried by the bloodstream to cells of other areas
Insulin (hormone) is produced and released by the _____ to increase ___ ____ __ _____
Insulin is produced and released by the pancreas to increase glucose uptake in cells
Growth hormone is produced in the _____ ____ to promote ___ _______
Growth hormone is produced in the pituitary gland to promote cell reproduction
_____ is produced by the hypothalamus to promote pair-bonding
Oxytocin is produced by the hypothalamus to promote pair-bonding
Epinephrine acts similarly to the ______ ______ _____, but lasts longer because the hormone ________________________________
Epinephrine acts similarly to the sympathetic nervous system, but lasts longer because the hormone stays in the bloodstream for a while after release
_____ is slower but more longer lasting than epinephrine
Cortisol is slower but more longer lasting than epinephrine
List the 3 functions of Cortisol
- Increases blood sugar by encouraging liver to release it
- Prompts breakdown of muscles and fat to make glucose
- Increases blood pressure, partly by retaining sodium and fluids
- Increasing total amount of blood plasma pumped through system
- Increasing resistance from the arteries
Cortisol acts as a stress hormone but also involved in _____ _____
Cortisol acts as a stress hormone but also involved in biological rhythms
When does Cortisol peak and decline?
Cortisol peaks soon after waking in the morning and slowing declines throughout the afternoon/evening
What happens when there is a disruption of the biological rhythm?
- Disruption of biological rhythm associated with severe stress/mental health issues
- After going through extreme stress, people’s bodies.
may begin to give up on responding to challenging
situations
- After going through extreme stress, people’s bodies.
List the 3 demographics that show smaller cortisol responses on waking
- Women with depression
- Women living with severe economic hardship
- Adults who experienced severe and/or chronic stress as children
List the 3 demographics that show smaller than normal cortisol responses to a stressful experience later in the day
- Children who have been abused or severely bullied
- Children experiencing chronic stress
- Adults who experienced greater stress as children
What are the 3 sex hormones?
Estrogen, progesterone, and testosterone
With respect to sex hormones, women have more _____ & ______ , men have more _______, both have all 3
Women have more estrogen & progesterone, men have more testosterone, both have all 3
Higher levels of _____ have mood enhancing effects in women and drops have been linked to _____ ______
Higher levels of estrogen have both mood enhancing effects in women and drops have been linked to depressive symptoms
Young women taking birth control (giving extra estrogen) are less prone to _______.
Young women taking birth control (giving extra estrogen) are less prone to depression
Testosterone has a ________ ____ in men with minor depression, especially if ___ levels of testosterone
Testosterone has a mood-enhancing effect in men with minor depression, especially if low levels of testosterone
- No significant effect if testosterone levels are normal
Certain children react to mistreatment with a burst of _______ release, matched with an outburst of _______ behaviour. However, most studies indicate low, often nonsignificant correlation between testosterone and anger/aggression
Certain children react to mistreatment with a burst of testosterone release, matched with outburst of disruptive/violent behaviour. However, most studies indicate low, often nonsignificant correlation between testosterone and anger/aggression
In both men and women, high ratio of ______ relative to _____ correlates with increased ________ behaviour and increased _______ behaviour
In both men and women, high ratio of testosterone relative to cortisol correlates with increased aggressive behaviour and increased risk taking behaviour
People with weak _______ _______ responses feel less guilt and fear, and therefore less restraint against antisocial acts (more willing to be agressive)
People with weak sympathetic system responses feel less guilt and fear, and therefore less restraint against antisocial acts (more willing to be agressive)
Heart rate is informally measured through
Heart rate is informally measured through changes in blood pressure when holding fingers against blood vessels to count beats
Electrocardiogram (ECG) is used to detect small electrical signals when the ______ and _______ begin to contract. Thus, in order for ECG to work it places sensors on the chest on a diagonal across the heart
Electrocardiogram (ECG) is used to detect small electrical signals when the atria (upper chambers of heart) and ventricles (lower chambers of heart) begin to contract. Thus, in order for ECG to work places sensors on chest on diagonal across the heart
Describe the most characteristic portion of the ECG response
QRS complex – heart beat pattern characterized by a big spike, then a dip, and then a return to a straight line
What does QRS stand for?
Q - beginning of the contraction
R - peak of electrical activity
S - indicates start of recovery
What are the 2 ways to analyze heart signals?
- Heart rate
- Blood pressure
What is one way that heart signals are analyzed by measuring heart rate?
Measuring number of R peaks in a given period of time and scaling to a minuet
What is a second (more common) way that heart signals are analyzed by measuring heart rate?
Measure average interbeat interval: time in ms between each of the R peaks in a ECG signal, and then average numbers for period of interest
- Allows researchers to detect changes on a second by
second basis