ch. 13

"slow"

"Slow" glucocorticoid response of the HPA axis

The hypothalamus

has projections down through the brainstem and spinal cord controls outgoing information in both branches of the autonomic nervous system

Norepinephrine

helps control alertness and arousal (noradrenaline)

HPA

hypothalamic-pituitary-adrenal axis

"Fast" sympathetic response

norepinephrine and adrenaline

pathophysiology

prolonged physiological imbalances can lead to disease

Slow Stress Response System

1) sensory info about threat reaches the amygdala. 2) amygdala sends signals to the hypothalamus via stria terminalis. (OTHER STEPS) --> 3) hippocampus has receptor sites for cortisol, activates to inhibit excessive release of GRH.

negative feedback loop

(to keep cortisol level in check) Hippocampus monitors cortisol levels for potential negative feedback

which of the preceding steps are part of the Cognitive contributors to emotion

-Attentional Deployment -Cognitive Change (attention, appraisal)

the process model of emotional regulation

-Situational Selection -Situation Modification -Attentional Deployment -Cognitive Change -Response Modulation

what happens in our bodies/brains when we get stressed? key players

1) the "HPA axis" 2) the autonomic nervous system 3) the central nervous system

systems inhibited by stress: Metabolic stress response

1. Stressor inhibits insulin Net effect: raises blood glucose (to feed brain and muscle) Blocks formation of glycogen, the storage form of glucose Promotes uptake of glucose by cells to generate energy for the cell 2. A prolonged stressor inhibits growth hormone (GH)

stress and performance

A moderate amount of stress is optimal for peak performance, but too much is deleterious Not a linear relationship (ie, more stress does not mean higher performance after a certain point) if stress is too low you get sleep/awareness, if it is too high you get anxiety/disorganization

Amygdala (AMYG) and hippocampus (HPC) regulate stress response (what stress response?)

AMYG: "on" switch HPC: "off" switch SLOW stress response

Core features of emotion regulation

Activation of regulatory goal, engagement of regulatory processes, effects on emotion dynamics e.g., latency, rise time, magnitude, duration, offset time

stress problem

Chronic, unrelieved stress --> Health problems

mouse experiment

Control over an aversive experience can greatly impact the organism's response to subsequent stressors. We compared the effects of escapable (ES) and yoked inescapable (IS) electric tail shocks on the hypothalamic-pituitary-adrenal (HPA) axis hormonal (corticosterone and ACTH), neural (c-fos mRNA) and behavioral (struggling) response to subsequent restraint. We found that although the HPA axis response during restraint of both previously stressed groups were higher than stress-naïve rats and not different from each other, lack of control over the tailshock experience led to an increase in restraint-induced struggling behavior of the IS rats compared to both stress-naïve and ES rats.

Historical Stress Conceptualizations: walter cannon

Fight or flight response, The concept of homeostasis

Historical Stress Conceptualizations: Hans Selye

General adaptation syndrome, Nonspecific response to many different kinds of stressors

EP AND NEP: These hormones quickly mobilize energy resources.

Increase in heart's output Increase in blood flow to muscles Decrease in blood flow to extremities

systems inhibited by stress: Gastrointestinal stress response

Inhibition of digestive enzymes --> Chronic stress associated with gastric ulcers Helicobacter pylori bacteria (weakens protective coating of stomach from acidic digestive juices)

effects of cortisol

Mobilization of amino acids and lipids for potential energy use, increased blood sugar, immune response initially increased (brief stress) and later decreased (chronic stress)

systems inhibited by stress: immune response

Normally, white blood cells (lymphocytes) release antibodies to destroy foreign invaders Chronically heightened cortisol suppresses lymphocyte activity Chronic stress leads to increased vulnerability to disease

other stress hormones -- Anterior pituitary gland: endorphin

Participates in reduced sensitivity to pain Adaptive: allows one to persist with "fight or flight" activity for extended period of time Endorphin = Endogenous morphine

Are chronic symptoms of stress associated with elevated heart rate?

Physiological hyperarousal is a component of post traumatic stress that poses a serious health risk. Diurnal heart rate patterns differed for patients with versus without post traumatic stress symptoms. In particular, patients with elevated symptoms showed: less nighttime dipping in heart rate and a 50% smaller peak-trough amplitude in heart rate (it was higher and dropped less)

Function of Stress Response

Purpose: Divert resources from homeostasis and long-term goals. Survive short-term threat. This is done by 1. Mobilize energy: inhibit energy storage (glucose) 2. Inhibit anabolic processes related to digestion, reproduction, growth, tissue repair, and immune system 3. Inhibit pain perception (endogenous opioids) and inflammation (corticosteroids)

General Adaptation Syndrome

Selye's concept of the body's adaptive response to stress in three phases—alarm, resistance, exhaustion.

Endocrine and nervous system relationship

So how are the endocrine and nervous system linked? The brain structure known as the hypothalamus connects these two important communication systems. The hypothalamus is a tiny collection of nuclei that is responsible for controlling an astonishing amount of behavior. Located at the base of the forebrain, the hypothalamus regulates basic needs such as sleep, hunger, thirst, and sex in addition to emotional and stress responses. The hypothalamus also controls the pituitary glands, which then controls the release of hormones from other glands in the endocrine system.

what is stress?

Stress is a perturbation that upsets the physiological balance and the body's efforts to reestablish balance.

autonomic nervous system

The autonomic nervous system is responsible for controlling involuntary functions such as certain aspects of heartbeat, respiration, digestion and blood pressure. This system is also related to emotional responses such as sweating and crying. The autonomic system can then be further subdivided into two subsystems known as the sympathetic and parasympathetic systems.

CNS

The central nervous system (CNS) is made up of the brain and spinal cord. The primary form of communication in the CNS is the neuron. The brain and spinal cord are absolutely vital to life and functioning Think of these structures as the literal "center" of the body's communication system. The CNS is responsible for processing every sensation and thought you experience. The sensory information that is gathered by receptors throughout the body then passes this information on to the central nervous system. The CNS also sends messages out to the rest of the body in order to control movement, actions, and responses to the environment.

the pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands. is called the "master gland" of the body releases hormones into the blood stream that cause a cascade of physiological responses

parasympathetic nervous system

The parasympathetic nervous system functions to counter the sympathetic system. After a crisis or danger has passed, this system helps to calm the body. Heart and breathing rates slow, digestion resumes, pupil contract and sweating ceases.

HPA axis' chain of responses to a stressor

The paraventricular nucleus of the hypothalamus secretes corticotropin releasing hormone (CRH) into the hypothalamic pituitary portal circulation to trigger... Release of adrenocorticotropic hormone (ACTH) from the anterior pituitary, which triggers... Release of cortisol from cortex of the adrenal gland

PNS

The peripheral system (PNS) is composed of a number of nerves that extend outside of the central nervous system. The nerves and nerve networks that make up the PNS are actually bundles of axons from neuron cells. Nerves can range from relatively small to large bundles that can be easily seen by the human eye. The PNS can be further divided into two different systems: the somatic nervous system and the autonomic nervous system.

somatic nervous system

The somatic system transmits sensory communications and is responsible for voluntary movement and action.

sympathetic nervous system

The sympathetic system controls the body's response to emergencies. When this system is aroused, a number of things begin to occur: your heart and breathing rates increase, digestion slows or stops, the pupils dilate and you begin to sweat. Known as the fight-or-flight response, this system responds by preparing your body to either fight the danger or flee.

Homeostasis and the nature of stress: Two systems respond to perceived threat to try and maintain normal functioning--what are they

Two systems respond to perceived threat to try and maintain normal functioning: Autonomic (i.e., sympathetic nervous system, specifically) Endocrine (i.e., hormonal)

"Fast" Stress Response: Sympathetic/Catecholamine Response

When stressor perceived by brain: In brainstem: Locus coeruleus releases norepinephrine, which influences the reticular formation. Results in arousal, vigilance for unpredictable emergencies Activation of sympathetic branch of autonomic nervous system Tachycardia (increased heart rate) Hypertension (increased blood pressure) Hyperthermia (decreased temperature regulation)

The sympathetic nervous system

activates the adrenal gland.

Epinephrine

adrenaline

stressor

agent that causes imbalance

adrenal glands

are located at the top of the kidneys release stress hormones into the bloodstream

Two main adrenal responses to a range of different kinds of stressors

fast and slow

stress response

response to the stressor

The adrenal medulla

secretes epinephrine and norepinephrine (catacholamines)

Diurnal Pattern of Cortisol

secretion with the highest levels in the morning and a gradual decrease throughout the day. CAR magnitude is higher on work days than on weekends. This difference is related to perceived stress levels. Low diurnal slope (i.e., less of a drop in stress throughout the day) predicts poor health: Increased coronary calcification, Reduced breast cancer recovery rates

fight or flight response

sequence of internal processes preparing an organism for struggle or escape

Is worrying associated with high blood pressure?

stressor --> Perseverative Cognition --> Subjective Stress --> Elevated Blood Pressure

the stress cycle (with physiology)

stressor --> Sympathetic Nervous System, FIGHT OR FLIGHT --> Chronic catecholamines and cortisol, resistance/continued coping --> Ulcers and cardiovascular disease, exhaustion and depletion

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream