Download Chapter 1: Introduction

Brain and Nervous System
Anatomy of the Brain: Structure and Function
Neurons: The Basic Unit of Communication
Neurotransmitters and Hormones
Neuroplasticity
Interdisciplinary Approach: Neuroscience
Begins with studying cells of the nervous system
Neurons
- up to one billion cells
- inter-connections up to 50,000 per neuron
Glia
- outnumber neurons 10:1
- function not incompletely understood
Studying the Nervous System
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Clinical observation
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Neuropsychology
Studying the Nervous System
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Experimental Techniques
Neuroimaging Techniques
Used to examine structures and functioning of brain
Computerized Tomography (CT):
Magnetic Resonance Imaging (MRI), functional MRI (fMRI):
Neuroimaging techniques, cont’d.
Positron Emission Tomography (PET):
Electroencephalography (EEG):
The Nervous System
Communication throughout the body
Highly organized network
Relays, processes, and integrates information
The Architecture of the Nervous System
Limbic System
Involved in the regulation of motivational and emotional
states
Aggression, fear, anxiety, appetite (stress-induced eating)
Kluver-Bucy Syndrome: (Humans)
The Cerebral Cortex
Cortical Brain Structures
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3 mm thickness; millions of cells
80% of total brain volume
Convoluted (folded) structure increases overall
amount of tissue (total area = 1 sq metre)
Divided into 2 hemispheres and 4 paired lobes:
frontal, temporal, occipital, parietal
Lateralization
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Two “sides” to the brain: LEFT and RIGHT hemispheres
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Contralateral organization:
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LEFT hemisphere controls actions of RIGHT side of body
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Most structures are bilateral
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Hemispheres connected through “commissures” – bundled neural
fibers
Cerebral Commissures
Tracts that connect the left and right cerebral hemispheres
Example: Corpus Callosum
Lateralization - Cerebral Asymmetry
Cortical Control of Sensory and Motor
Information
(Sensory and Motor Homunculus)
The Developing Nervous System
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Neurogenesis:
 Differentiation among cells
 Proliferation of cells; Migration
 Nearly complete by month 5 of uterine gestation in
humans
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Connections among neurons and selective death of
neurons: (Pruning/Wiring)
Can continue into adulthood.
The Neuron
Characteristics of the Neuron
Communication within the Neuron
Communication between Neurons
Communication within the Neuron
Distribution of charged particles; ions
Sodium; Potassium
Communication within the Neuron
Action Potential
Momentary change from about -70 mV to +50 mV.
Communication between Neurons
Neurotransmitters and Receptors
Endorphins, NPY, PYY,
Urocortin, Substance P.
Neurotransmitter vs Hormone
[Hormones are chemicals released by endocrine
glands into blood circulation]
Some final thoughts on the CNS…..
The Brain is “PLASTIC”