Chapter 2
Biological Foundationsand the Brain
Copyright © 1999 by The McGraw-Hill Companies, Inc. 2
The Genetic Perspective
• Chromosomes• threadlike structures located in the nucleus of each
human cell
• Deoxyribonucleic Acid (DNA)• a complex molecule that contains genetic information
• Genes• short segments of DNA that are the units of heredity
information
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Perspectives on Natureand Nurture
• Environment– all of the surrounding conditions and influences
that affect the development of living things• Nurture
– an organism’s environmental experiences• Nature
– an organism’s biological inheritance
Copyright © 1999 by The McGraw-Hill Companies, Inc. 4
Perspectives on Natureand Nurture
• Dominant-recessive genes principle– the principle that if one gene of a pair is
dominant and the other is recessive, the dominant gene exerts its effect, overriding the potential influence of the recessive gene. A recessive gene exerts its influence only if both genes of the pair are recessive
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The Evolutionary Perspective
• Natural selection– the evolutionary process that favors the
individuals within a species that are best adapted to survive and reproduce in their particular environment
• Evolutionary psychology– emphasizes the roles of evolution and
psychological mechanisms in adaptive behavior
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The Nervous System
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The Nervous System
• Neurons• Central Nervous System (CNS)• Peripheral nervous system• Somatic nervous system• Autonomic nervous system
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The Nervous System
• Sympathetic nervous system– the division of the autonomic nervous system
that arouses the body• Parasympathetic nervous system
– the division of the autonomic nervous system that calms the body
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Neural Transmission
• Afferent nerves– sensory nerves that carry information to the
brain• Efferent nerves
– motor nerves that carry the brain’s output• Interneurons
– CNS neurons that mediate sensory input and motor output
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Structure of the Neuron
• Cell body• Dendrite• Axon• Myelin sheath
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The Nerve Impulse
• Ions• Resting potential• Action Potential• All-or-none principle
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Synapses and Neurotransmitters
• Synapses• Neurotransmitters
– dopamine– serotonin– endorphins
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The Central Nervous System
• Hindbrain– Medulla– Cerebellum– Pons
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The Central Nervous System
• Midbrain– Reticular Formation– Basal ganglia
• Forebrain– Thalamus– Hypothalamus
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The Central Nervous System
• Endocrine system– Hormones– Pituitary gland
• Limbic system– Amygdala– Hippocampus
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The Central Nervous System
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The Central Nervous System
• Cerebral Cortex (Cerebrum)– Occipital lobe– Temporal lobe– Frontal lobe– Parietal lobe
• Association cortex
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The Central Nervous System
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Split-Brain Research and theCerebral Hemisphere
• Split-brain research– Corpus Callosum
• Hemispheric specialization• His brain and her brain• Aphasia• Localization and integration of function
– phrenology
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Brain Damage, Plasticity,and Repair
• The brain’s plasticity and capacity for repair– collateral sprouting– substitution of function
• Brain tissue implants– the implantation of healthy tissue into damaged
brains
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Techniques for Studyingthe Brain
• Electroencephalograph (EEG)• Computer-assisted Axial Tomography
(CAT scan)• Positron-Emission Tomography (PET scan)• Magnetic Resonance Imaging (MRI)• Superconducting Quantum Interference
Device (SQUID)
