Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
“Copyright © Allyn & Bacon 2007
The Neuron������������
�The basic unit of the nervous system� Receives signals from neurons or sense
organs� Processes signals� Sends signals to other neurons, muscles, or
organs
�The brain contains 100 billion neurons
“Copyright © Allyn & Bacon 2007
Categories of neurons� Sensory neurons ��������������������
� transmit impulses received by receptors�� � � �to the central nervous system
� Motor neurons � � ���� � ���� � ���� � ���� carry outgoing signals from the brain or spinal cord
to muscles and glands� Interneurons � � � � / � ��� � ��� � ��� � ���
� receive the signals from the sensory neurons and send impulses to other interneurons or to motorneurons. Found only in the brain, eyes and spinal cord
Brain circuit: A set of neurons that affect one another
“Copyright © Allyn & Bacon 2007
Neural Impulses����������������
� Resting potential�� � � �
� More positively charged ions outside than inside�� � � � � � �
� Action potential: “Firing” � � � �
Threshold exceeded � � / �
� Flow of ions through channels in membrane�� � � � �
� All-or-none law( � � � � � �
“Copyright © Allyn & Bacon 2007
Complexity of the Brain
� Is the brain the single most complex object in the universe?� 100,000,000,000 (100 billion) neurons� Average of 10,000 connections for each neuron� 10,000,000,000,000 (10 trillion) neural
connections!
“Copyright © Allyn & Bacon 2007
Neurotransmitters:������
Dopamine����� � �� � �� � �� � � ����
Release of dopamine in certain areas of the brain produces intense feelings of pleasure. Too much dopamine in some areas of the brain may cause schizophrenia ( � � � � � ), while too little in other areas may lead to Parkinson’s disease ( � � � ).
Serotonin ( � � �� � �� � �� � � ����
� Role in mood regulation, role in depression (low levels)
� Important in the regulation of sleep and appetite
“Copyright © Allyn & Bacon 2007
� The central nervous system � � � � �
� all the neurons in the brain and spinal cord
� The peripheral nervous system � � � � � �
� all the nerves connecting the brain and spinal cord to other parts of the body
� Somatic system � � / � � � � � �
� subdivision of the peripheral nervous system that carries messages to and from the sense receptors, muscles and the surface of the body
� Autonomic system � � /� � � � � �
� subdivision of the peripheral nervous system that connects with the internal organs and glands
The Organization of the Nervous SystemThe Organization of the Nervous System
“Copyright © Allyn & Bacon 2007
The Nervous System
Central Nervous System
P eri p h eral Nervous System
Sensory-Somati cNervous System
A utonomi cNervous System
P arasymp ath eti cNervous System
Symp ath eti cNervous System
Motor Output
Sensory I np utMo
tor O
utput
“Copyright © Allyn & Bacon 2007
The Peripheral Nervous System������������������������
� Autonomic Nervous System � � / � � � � � �� Sympathetic����
� Emergency preparedness� Fight-or-flight� Increased arousal
� Parasympathetic� ����
� Decreased arousal
� The Sensory-Somatic Nervous System����� � � �� Input-output connections� Cranial nerves� � � ��
� Skeletal system � �
“Copyright © Allyn & Bacon 2007
The Brain: Structures
� Meninges � �
� Cerebral hemisphere� � �
� Lobes�
� Corpus collosum� �
� Cerebral cortex� � � �
“Copyright © Allyn & Bacon 2007
The Brain: Lobes��������
� Occipital lobes �
� Temporal lobes �
� Parietal lobes �
� Frontal lobes�
“Copyright © Allyn & Bacon 2007
The Occipital Lobes � �� �� �� �
� At the back of the head
� Functions include� Visual processing
� Seeing stars?
“Copyright © Allyn & Bacon 2007
The Temporal Lobes � �� �� �� �
� In front of the ears� Functions include
� Language comprehension� Sound processing� "Entering new information
in memory"� "Storing visual memories"
“Copyright © Allyn & Bacon 2007
The Parietal Lobes � �� �� �� �
� Top, rear of the brain� Functions include
� Attention� Spatial location� Somatosensory
processing
“Copyright © Allyn & Bacon 2007
The Frontal Lobes � �� �� �� �
� Front of the brain � Functions include
� Planning� Memory search� Motor processing� Reasoning
� Phineas Gage
“Copyright © Allyn & Bacon 2007
Asymmetries of the BrainAsymmetries of the Brain
LeftLeftHemisphereHemisphere
RightRightHemisphereHemisphere
SplitSplit--Brain SurgeryBrain Surgery
Corpus Corpus CallosumCallosum
“Copyright © Allyn & Bacon 2007
Hemispheric Specialization� Left hemisphere
� expressive language� logical activities� mathematical computation
� Right hemisphere� spatial and pattern recognition� facial identity and expressions of emotion� line slopes and dot locations
“Copyright © Allyn & Bacon 2007
Split-Brain Surgery
Severed CorpusCallosum
��Asymmetries of the BrainAsymmetries of the Brain
“Copyright © Allyn & Bacon 2007
After Split-Brain Surgery
Asymmetries of the BrainAsymmetries of the Brain
“Copyright © Allyn & Bacon 2007
Subcortical Brain Areas
� Thalamus: Crossroads� Hypothalamus: Thermostat� Hippocampus: Remember� Amygdala: Inner feelings� Basal ganglia� � � : More
than habit-forming � � � � �
� � � �
� Brainstem: Wakeup call� Cerebellum: Walking tall
“Copyright © Allyn & Bacon 2007
The Endocrine System ����� � � � �� � � � �� � � � �� � � � � ����
It acts more slowly, indirectly affecting the activities of cell groups throughout the body. It does so by means of hormones.
� Glands����� � � �� � � �� � � �� � � � ����:organs located throughout the body that secrete special substances such as sweat, milk or particular hormones
� Hormones����� � � � � � � � ����:chemicals secreted by the endocrine glands into the bloodstream and transported to other parts of the body
� Pituitary Gland ( � � � � � � � � / � �� �� �� � ����:the “master gland”, controls the secretion activity of other endocrine glands. One of the pituitary hormones has the crucial job of controlling of the body’s growth.
� The adrenal glands����� � �� � �� � �� � � ����:It plays an important role in determining mood, energy level, and ability to cope with stress.
“Copyright © Allyn & Bacon 2007
Probing the Brain � � �� � �� � �� � �� Detecting electrical activity
� Electroencephalograph (EEG) � �
� Magnetoencephalography (MEG)� Single-cell recording
� Visualizing structure� Computer-assisted tomography (CT scan)���
� � �
� Magnetic resonance imaging (MRI) � � �
� Visualizing function� Positron emission tomography (PET) � � � �
� � �
� Functional magnetic resonance imaging (fMRI)
“Copyright © Allyn & Bacon 2007
Pictures of the Living BrainPictures of the Living Brain
CAT ScanCAT Scan
��
“Copyright © Allyn & Bacon 2007
MRI ScanMRI Scan
Pictures of the Living BrainPictures of the Living Brain
“Copyright © Allyn & Bacon 2007
PET ScanPET Scan
Pictures of the Living BrainPictures of the Living Brain
“Copyright © Allyn & Bacon 2007
Pictures of the Pictures of the Living BrainLiving Brain
PET ScanRed areas
indicate maximum brain
activity; blue areas show
minimum activity..
“Copyright © Allyn & Bacon 2007
Observing the Brain
� Brain damage� Lesion� Stroke
� Stimulating the brain� Transcranial magnetic stimulation (TMS)
“Copyright © Allyn & Bacon 2007
Genetic Studies and Behavior
� Selective breeding� animals that are high or low in a certain behavior or
physical trait are mated with each other� Twin studies
� monozygotic (identical), dizygotic (fraternal) twins� Molecular genetics������������������������
� influence of specific genes on personality, and other specific behavioral traits
� Environmental influences on gene action� role of environment and interaction in manifestation of
a behavior or particular disorder