HEALTH PSYCHOLOGY PART 2: BIOPSYCHOLOGICAL INTERACTIONS
CLASS 1: HOMEOSTATIC REGULATION
HOMEOSTATIC REGULATION
= an organisms ability to keep internal environment stable, despite changes in external environment
• Examples:
o temperature
o blood pH
o oxygen pressure
o blood glucose
• Balance!
• Central nervous system = interface for interaction with external environment
• Stress = threat to homeostasis
o Stressor (= what causes the stress)
▪ Physical (e.g. cold)
▪ = bottom up: we sense it, comes from physiology
▪ Psychological (e.g. anticipation of pain, exam)
▪ = top down
o Compensatory stress response (= what the organism is doing to get the system back
to its balance)
HOMEOSTASIS
(NEGATIVE) FEEDBACK CONTROL
1) Temperature:
- Dilate = get wider
- Constrict = get narrower
2) Blood pressure:
1
, - Glossopharyngeal nerve = very important!
- Parasympathetic activation increases, sympathetic decreases if blood pressure decreases
3) Blood pH/PaCO2:
FEEDFORWARD CONTROL
• Perturbations (= verstoringen) are anticipated & corrected before they occur
• Classical conditioning as a viable mechanism
o e.g. Exercise hyperpnea
▪ hyper = a lot, pnea = breath
▪ = breathing a lot before exercise
2
, • Increases in ventilation and heart rate occur at onset of physical exercise, even before
increase in PaCO2
o At the onset of exercise, our body prepares us to react on the coming changes
A HIERARCHY OF HOMEOSTATIC CONTROLS
Higher in the hierarchy = more complex system
VITAL ORGANS & LOCAL REFLEXES
= the organ level: intrinsic control mechanisms
• Organ adapts its functioning on its own in response to slow, local changes
• Example: Frank Starling Mechanism
o IF more blood returns from the body through vena cava => atrium chambers more
volume => fuller ventricles => more wall stretch => more muscle fiber tension =>
more vigorous contraction in that beat => left ventricle empties more completely =>
more effective blood flow into aorta
o SO more blood flow = more powerful contraction
o SO: the heart responses to flow demands caused by systemic circulation
o = only possible when conditions are relatively stable
AUTONOMOUS NERVOUS SYSTEM (ANS)
3
, Brainstem controls => autonomic messages
• Signal transmission in ANS: dendrites > cell body > axon > synapse > NT
• Viscera (internal organs): limited awareness & voluntary control ~ ‘autonomic’
• Works mostly through negative feedback
• Keeps our higher brain centres and energy free to do more important things
• ANS
o Sensory pathways (afferent = up = ascending)
o Motor pathways (efferent = down = descending)
o Divisions:
▪ Sympathetic (SNS)
▪ Parasympathetic (PNS)
▪ Enteric
▪ Not clear if this belongs to ANS
o Reciprocal regulation of organic function
Each division has:
• Sensory pathways from organs via ganglia to brainstem (afferent, = ascending parts)
+
• 4 response components (= descending parts):
o Descending autonomic and pre-ganglionic fibers
▪ Hypothalamus/brainstem => towards intermediolateral cell column of spinal
cord
o Ganglion
4
CLASS 1: HOMEOSTATIC REGULATION
HOMEOSTATIC REGULATION
= an organisms ability to keep internal environment stable, despite changes in external environment
• Examples:
o temperature
o blood pH
o oxygen pressure
o blood glucose
• Balance!
• Central nervous system = interface for interaction with external environment
• Stress = threat to homeostasis
o Stressor (= what causes the stress)
▪ Physical (e.g. cold)
▪ = bottom up: we sense it, comes from physiology
▪ Psychological (e.g. anticipation of pain, exam)
▪ = top down
o Compensatory stress response (= what the organism is doing to get the system back
to its balance)
HOMEOSTASIS
(NEGATIVE) FEEDBACK CONTROL
1) Temperature:
- Dilate = get wider
- Constrict = get narrower
2) Blood pressure:
1
, - Glossopharyngeal nerve = very important!
- Parasympathetic activation increases, sympathetic decreases if blood pressure decreases
3) Blood pH/PaCO2:
FEEDFORWARD CONTROL
• Perturbations (= verstoringen) are anticipated & corrected before they occur
• Classical conditioning as a viable mechanism
o e.g. Exercise hyperpnea
▪ hyper = a lot, pnea = breath
▪ = breathing a lot before exercise
2
, • Increases in ventilation and heart rate occur at onset of physical exercise, even before
increase in PaCO2
o At the onset of exercise, our body prepares us to react on the coming changes
A HIERARCHY OF HOMEOSTATIC CONTROLS
Higher in the hierarchy = more complex system
VITAL ORGANS & LOCAL REFLEXES
= the organ level: intrinsic control mechanisms
• Organ adapts its functioning on its own in response to slow, local changes
• Example: Frank Starling Mechanism
o IF more blood returns from the body through vena cava => atrium chambers more
volume => fuller ventricles => more wall stretch => more muscle fiber tension =>
more vigorous contraction in that beat => left ventricle empties more completely =>
more effective blood flow into aorta
o SO more blood flow = more powerful contraction
o SO: the heart responses to flow demands caused by systemic circulation
o = only possible when conditions are relatively stable
AUTONOMOUS NERVOUS SYSTEM (ANS)
3
, Brainstem controls => autonomic messages
• Signal transmission in ANS: dendrites > cell body > axon > synapse > NT
• Viscera (internal organs): limited awareness & voluntary control ~ ‘autonomic’
• Works mostly through negative feedback
• Keeps our higher brain centres and energy free to do more important things
• ANS
o Sensory pathways (afferent = up = ascending)
o Motor pathways (efferent = down = descending)
o Divisions:
▪ Sympathetic (SNS)
▪ Parasympathetic (PNS)
▪ Enteric
▪ Not clear if this belongs to ANS
o Reciprocal regulation of organic function
Each division has:
• Sensory pathways from organs via ganglia to brainstem (afferent, = ascending parts)
+
• 4 response components (= descending parts):
o Descending autonomic and pre-ganglionic fibers
▪ Hypothalamus/brainstem => towards intermediolateral cell column of spinal
cord
o Ganglion
4
