JANUARY 2019
BIOLOGICAL PSYCHOLOGY:
THE HUMAN BODY
1.4 C
JIM LEFERINK OP REININK
ERASMUS UNIVERSITY ROTTERDAM
Psychology, Ba-1, 2017-2018
,TABLE OF CONTENTS
PROBLEM 1: BRAIN AND BODY ..................................................................................................... 3
GENERAL LAYOUT OF THE NERVOUS SYSTEM.................................................................................................3
CELLS OF THE NERVOUS SYSTEM .................................................................................................................7
SPINAL CORD AND THE BRAIN .................................................................................................................. 11
PROBLEM 2: TWO SIDES ............................................................................................................. 20
CEREBRAL LATERALIZATION OF FUNCTION.................................................................................................. 20
THE SPLIT BRAIN.................................................................................................................................... 22
LEFT AND RIGHT HEMISPHERES ................................................................................................................ 25
HANDEDNESS ........................................................................................................................................ 32
PROBLEM 3: INSIDE THE NEURON............................................................................................... 34
THE NERVE IMPULSE .............................................................................................................................. 34
THE CONCEPT OF THE SYNAPSE ................................................................................................................ 40
PROBLEM 4: DRUGS ................................................................................................................... 51
BASIC PRINCIPLES OF DRUG ADDICTION .................................................................................................... 51
COMMONLY ABUSED DRUGS ................................................................................................................... 58
DRUGS AND THE BRAIN........................................................................................................................... 64
PROBLEM 5: GENDER ISSUES ...................................................................................................... 68
NEUROENDOCRINE SYSTEM ..................................................................................................................... 68
SEXUAL DEVELOPMENT OF THE BODY........................................................................................................ 74
SEXUAL DEVELOPMENT OF BRAIN AND BEHAVIOUR ..................................................................................... 82
EXCEPTIONAL HUMAN SEXUAL DEVELOPMENT ........................................................................................... 85
SEXUAL ORIENTATION AND SEXUAL IDENTITY ............................................................................................. 86
PROBLEM 6: BON APPÉTIT! ........................................................................................................ 88
DIGESTION AND ENERGY ......................................................................................................................... 88
THEORIES OF HUNGER AND EATING .......................................................................................................... 93
HUNGER AND THE BRAIN ........................................................................................................................ 97
BODY WEIGHT REGULATION.................................................................................................................. 102
PROBLEM 7: NIGHT, NIGHT ...................................................................................................... 107
STAGES OF SLEEP ................................................................................................................................. 107
COMMON BELIEFS ABOUT SLEEPING ....................................................................................................... 110
EFFECTS OF SLEEP DEPRIVATION............................................................................................................. 112
CIRCADIAN SLEEP CYCLES ...................................................................................................................... 114
SLEEP AND THE BRAIN .......................................................................................................................... 117
PROBLEM 8: STRESS ................................................................................................................. 122
STRESS RESPONSES .............................................................................................................................. 122
STRESSORS, CONTEXTS, AND REACTIONS ................................................................................................. 126
STRESS AND HEALTH ............................................................................................................................ 127
THE IMMUNE SYSTEM .......................................................................................................................... 128
STRESS AND THE BRAIN......................................................................................................................... 131
2
,PROBLEM 1: BRAIN AND BODY
GENERAL LAYOUT OF THE N ERVOUS SYSTEM
Central nervous system (CNS) – The division of the nervous system located within the skull and spine. The CNS
is composed of two divisions: the brain (in the skull) and the spinal cord (in the spine).
Afferent nerves – Carry sensory signals to the central nervous system. Every sensory neuron is an afferent to
the rest of the nervous system.
Efferent nerves – Carry motor signals from the central nervous system. Every motor neuron is an efferent from
the nervous system.
Within the nervous system, a given neuron is an efferent from one structure and an afferent to another.
Peripheral nervous system (PNS) – The division of the nervous system located outside the skull and spine.
• Somatic nervous system (SNS) – The part of the PNS that interacts with the external environment
(either voluntary or involuntary). It is composed of afferent nerves that carry sensory signals from the
skin, skeletal muscles, eyes, ears, and so on to the CNS and efferent nerves that carry motor signals
from the CNS to the skeletal muscles.
• Autonomic nervous system (ANS) – The part of the PNS that regulates the body’s internal environment
(involuntary). It is composed of afferent nerves that carry sensory signals from internal organs to the
CNS and efferent nerves that carry motor signals from the CNS to internal organs.
The autonomic nervous system has two kinds of efferent nerves: sympathetic nerves and parasympathetic
nerves.
• Sympathetic nerves – Autonomic motor nerves that project from the CNS in the lumbar (small of the
back) and thoracic (chest area) regions of the spinal cord.
• Parasympathetic nerves – Autonomic motor nerves that project from the brain and sacral (lower back)
region of the spinal cord.
All sympathetic and parasympathetic nerves are two-stage neural paths: The sympathetic and parasympathetic
neurons project from the CNS and go only part of the way to the target organs before they synapse on other
neurons (second-stage neurons) that carry the signals the rest of the way. However, note that the sympathetic
neurons project from the CNS synapse on second-stage neurons at a substantial distance from their target
organs, whereas the parasympathetic neurons that project from the CNS synapse near their target organs on
very short second-stage neurons.
The sympathetic (fight-flight) and parasympathetic (rest-digest) systems rely on three important principles:
1. Sympathetic nerves stimulate, organize, and mobilize energy resources in threatening situations,
whereas parasympathetic nerves act to conserve energy.
2. Each autonomic target organ receives opposing sympathetic and parasympathetic input, and its activity
is thus controlled by relative levels of sympathetic and parasympathetic activity.
3. Sympathetic changes are indicative of psychological arousal, whereas parasympathetic changes are
indicative of psychological relaxation.
3
, Cranial nerves – Project from the brain and consist of 12 pairs; most of the nerves of the peripheral nervous
system project from the spinal cord, but these 12 pairs of cranial nerves form an exception. The cranial nerves
include purely sensory nerves such as the olfactory nerves (smell) and the optic nerves, but most contain both
sensory and motor fibres. The autonomic motor fibres of the cranial nerves are parasympathetic.
4
BIOLOGICAL PSYCHOLOGY:
THE HUMAN BODY
1.4 C
JIM LEFERINK OP REININK
ERASMUS UNIVERSITY ROTTERDAM
Psychology, Ba-1, 2017-2018
,TABLE OF CONTENTS
PROBLEM 1: BRAIN AND BODY ..................................................................................................... 3
GENERAL LAYOUT OF THE NERVOUS SYSTEM.................................................................................................3
CELLS OF THE NERVOUS SYSTEM .................................................................................................................7
SPINAL CORD AND THE BRAIN .................................................................................................................. 11
PROBLEM 2: TWO SIDES ............................................................................................................. 20
CEREBRAL LATERALIZATION OF FUNCTION.................................................................................................. 20
THE SPLIT BRAIN.................................................................................................................................... 22
LEFT AND RIGHT HEMISPHERES ................................................................................................................ 25
HANDEDNESS ........................................................................................................................................ 32
PROBLEM 3: INSIDE THE NEURON............................................................................................... 34
THE NERVE IMPULSE .............................................................................................................................. 34
THE CONCEPT OF THE SYNAPSE ................................................................................................................ 40
PROBLEM 4: DRUGS ................................................................................................................... 51
BASIC PRINCIPLES OF DRUG ADDICTION .................................................................................................... 51
COMMONLY ABUSED DRUGS ................................................................................................................... 58
DRUGS AND THE BRAIN........................................................................................................................... 64
PROBLEM 5: GENDER ISSUES ...................................................................................................... 68
NEUROENDOCRINE SYSTEM ..................................................................................................................... 68
SEXUAL DEVELOPMENT OF THE BODY........................................................................................................ 74
SEXUAL DEVELOPMENT OF BRAIN AND BEHAVIOUR ..................................................................................... 82
EXCEPTIONAL HUMAN SEXUAL DEVELOPMENT ........................................................................................... 85
SEXUAL ORIENTATION AND SEXUAL IDENTITY ............................................................................................. 86
PROBLEM 6: BON APPÉTIT! ........................................................................................................ 88
DIGESTION AND ENERGY ......................................................................................................................... 88
THEORIES OF HUNGER AND EATING .......................................................................................................... 93
HUNGER AND THE BRAIN ........................................................................................................................ 97
BODY WEIGHT REGULATION.................................................................................................................. 102
PROBLEM 7: NIGHT, NIGHT ...................................................................................................... 107
STAGES OF SLEEP ................................................................................................................................. 107
COMMON BELIEFS ABOUT SLEEPING ....................................................................................................... 110
EFFECTS OF SLEEP DEPRIVATION............................................................................................................. 112
CIRCADIAN SLEEP CYCLES ...................................................................................................................... 114
SLEEP AND THE BRAIN .......................................................................................................................... 117
PROBLEM 8: STRESS ................................................................................................................. 122
STRESS RESPONSES .............................................................................................................................. 122
STRESSORS, CONTEXTS, AND REACTIONS ................................................................................................. 126
STRESS AND HEALTH ............................................................................................................................ 127
THE IMMUNE SYSTEM .......................................................................................................................... 128
STRESS AND THE BRAIN......................................................................................................................... 131
2
,PROBLEM 1: BRAIN AND BODY
GENERAL LAYOUT OF THE N ERVOUS SYSTEM
Central nervous system (CNS) – The division of the nervous system located within the skull and spine. The CNS
is composed of two divisions: the brain (in the skull) and the spinal cord (in the spine).
Afferent nerves – Carry sensory signals to the central nervous system. Every sensory neuron is an afferent to
the rest of the nervous system.
Efferent nerves – Carry motor signals from the central nervous system. Every motor neuron is an efferent from
the nervous system.
Within the nervous system, a given neuron is an efferent from one structure and an afferent to another.
Peripheral nervous system (PNS) – The division of the nervous system located outside the skull and spine.
• Somatic nervous system (SNS) – The part of the PNS that interacts with the external environment
(either voluntary or involuntary). It is composed of afferent nerves that carry sensory signals from the
skin, skeletal muscles, eyes, ears, and so on to the CNS and efferent nerves that carry motor signals
from the CNS to the skeletal muscles.
• Autonomic nervous system (ANS) – The part of the PNS that regulates the body’s internal environment
(involuntary). It is composed of afferent nerves that carry sensory signals from internal organs to the
CNS and efferent nerves that carry motor signals from the CNS to internal organs.
The autonomic nervous system has two kinds of efferent nerves: sympathetic nerves and parasympathetic
nerves.
• Sympathetic nerves – Autonomic motor nerves that project from the CNS in the lumbar (small of the
back) and thoracic (chest area) regions of the spinal cord.
• Parasympathetic nerves – Autonomic motor nerves that project from the brain and sacral (lower back)
region of the spinal cord.
All sympathetic and parasympathetic nerves are two-stage neural paths: The sympathetic and parasympathetic
neurons project from the CNS and go only part of the way to the target organs before they synapse on other
neurons (second-stage neurons) that carry the signals the rest of the way. However, note that the sympathetic
neurons project from the CNS synapse on second-stage neurons at a substantial distance from their target
organs, whereas the parasympathetic neurons that project from the CNS synapse near their target organs on
very short second-stage neurons.
The sympathetic (fight-flight) and parasympathetic (rest-digest) systems rely on three important principles:
1. Sympathetic nerves stimulate, organize, and mobilize energy resources in threatening situations,
whereas parasympathetic nerves act to conserve energy.
2. Each autonomic target organ receives opposing sympathetic and parasympathetic input, and its activity
is thus controlled by relative levels of sympathetic and parasympathetic activity.
3. Sympathetic changes are indicative of psychological arousal, whereas parasympathetic changes are
indicative of psychological relaxation.
3
, Cranial nerves – Project from the brain and consist of 12 pairs; most of the nerves of the peripheral nervous
system project from the spinal cord, but these 12 pairs of cranial nerves form an exception. The cranial nerves
include purely sensory nerves such as the olfactory nerves (smell) and the optic nerves, but most contain both
sensory and motor fibres. The autonomic motor fibres of the cranial nerves are parasympathetic.
4
