1. Stress Psychophysiology
Chapter 2

2. Chapter Overview Components of the brain and body involved with stress
Stress pathways (endocrine, autonomic)
Other components involved:
cardiovascular system
gastrointestinal system
muscles, skin

3. The Brain Two major components Cerebral cortex (thinking functions)
Subcortex (physiological processes)

4. Subcortex Includes the Limbic System (“seat of emotions”)
Thalamus
Hypothalamus
See Figure 2.1
Diencephalon

5. The Brain Hippocampus (sounds the stress alarm)
Cerebellum (coordinates body movement)
Pons (regulates sleep)
Medulla oblongata (heart beat, respiration)

6. Did You Know? Adrenal glands release glucocorticoids during stress
Glucocorticoids are detected by hippocampal cells
With prolonged stress, these cells are damaged and possibly lost forever

7. Stress and Its Pathways
The hypothalamus activates the following under a stress response:
Autonomic nervous system
Immediate fight-or-flight response
Endocrine system
Short-term and long-term stress response

8. Stress and It’s Pathways

9. Autonomic Nervous System
Two systems working together during immediate stress:
Sympathetic (responsible for expending energy)
Parasympathetic (responsible for conserving energy)
Figure 2.6 shows innervation of both divisions of the ANS

10. Endocrine System Includes glands that secrete hormones
Hormones travel through the blood stream
These hormones change function of bodily tissues
See Figure 2.3

11. Major endocrine glands

12. Endocrine System (cont.)
Four pathways
Adrenal Medulla
Adrenal Cortex
Thyroid
Vasopressin (ADH) and Oxytocin

13. Adrenal Medulla
Secretes two catecholamines: epinephrine (adrenalin) and norepinephrine (noradrenalin)
Effects remain 10 times longer than adrenal corticoids and include:
Increased heart rate
Increased stroke force
Dilation of coronary arteries
Dilation of bronchial tubes
Increased basal metabolic rate
Constriction of vessels to skin of arms, legs, muscles
Increased O2 consumption

14. Adrenal Cortex Influenced by the hypothalamus and pituitary gland
Adrenal cortex secretes glucocorticoids and mineralocorticoids
Primary glucocorticoid is cortisol
Primary mineralocorticoid is aldosterone
Cortisol provides fuel for “fight-or-flight” action
Aldosterone increases blood pressure to prepare for action

15. Thyroid Influenced by the hypothalamus and pituitary gland
Thyroid gland secretes thyroxin
Increases the following:
basal metabolic rate
free fatty acids
gluconeogenesis
gastrointestinal motility
respiration
heart rate
blood pressure
anxiety

16. Vasopressin (ADH) and Oxytocin
ADH and oxytocin are produced by the pituitary gland
ADH acts on the kidneys to decrease urine production via water retention
Oxytocin increases contraction of the walls of blood vessels
Together, these two changes will increase blood pressure

17. The Autonomic Nervous System

18. The Cardiovascular System
Transports blood to cells and organs
Stress on the circulatory system may cause release of oxytocin and vasopressin
Both can constrict blood vessels, leading to increased blood pressure
Heart responds with increased force of contraction
Cholesterol and free fatty acids increase risk of heart disease

20. The Gastrointestinal System
Responsible for digestion
Stress reduces saliva production and increases hydrochloric acid production
Ulcers can develop
Stress can alter rhythmic movement of food, leading to bowel distress and diseases

21. The Muscles Stress results in tensing, known as “bracing”
Leads to the development of muscle pain and aches

22. The Skin Involved with stress response
Temperature and electrical conduction affected
Stress causes increased perspiration
Vasoconstriction occurs during stress, causing skin color to change

23. Stress Psychophysiology