Chapter 3 - Neuroscience & Behavior
MODULE 3-1 (7) - Neurons
Structure of Neurons
Neurons: Nerve Cells
Consist of cell body that contains nucleus
Distinctive Feature of neurons
Dendrite - cluster of fibers at end of neuron that receives messages from other neurons
Axon - part of the neuron that carries messages destined for other neurons.
Terminal Buttons - sends messages
How Neurons Fire
Neurons follow an all-or-none law - rule that neurons are either on or off
Resting state - negative electrical charge of about -70 millivolts within a neuron
Before a neuron is triggered
Action potential - electric nerve
Speed of Transmission
Speed in which an action potential travels along an axon is determined by
- Axon’s Size
- Thickness of myelin sheath
Neurons differ in terms of
- Quickness of impulse moving along axon
- Potential firing rate
Intensity of stimulus determines fire rate
Mirror Neurons
Specialized Neurons that fire, when a person:
Discovery of mirror neurons suggest that humans’ capacity to mitate other may be a inbor behavior
Helps in explaining how and why humans have the capacity to understand others’ intentions
Possible basis for:
Where Neurons Meet: Bridging The Gap
Synapse: Space between 2 neurons when axon of sending neuron communicates dendrites of receiving neuron by using chemical messages
Neurotransmitters: Chemicals that carry messages across the synapse to the dendrite ( an sometimes the cell body) of receiving neuron
Not every neuron is capable of receiving chemical message carried by particular neurotransmitter
Successful chemical communication is possible only when neuro
Types of chemical messages delivered by neurotransmitters:
If neurotransmitters remained at the side of the synapse, it would lead to:
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Receiving nero's awash, in a continual chemical bath
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Producing constant simulation of or coinhibilition of receiving neurons
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Effective communications would no longer be possible
Reuptake: reabsorption of neurotransmitters by a terminal buttons
MODULE 3-2 (8): Nervous System and Endocrine System
Central/Peripheral Nervous System
Central Nervous System: parts of the nervous system that includes brain and spinal cord
Reflex: Automatic, involuntary response to an incoming stimulus
Kinds of neurons involved in reflexes:
Peripheral Nervous Systems: made up of neurons with long axons and dendrites, it branches out from spinal cord and brain and reaching extremities of body
Includes
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Somatic Division
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Autonomic Division
Activating Divisions of Autonomic Nervous Systems
Autonomic Nervous system consists of
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Sympathetic Division
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Parasympathetic Division
Evolutionary Foundations of Nervous System
Endocrine System: Chemicals/Glands
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Endocrine system - chemical communication network that sends messages
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Hormones - circulates through the blood
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Pituitary gland - major component of endocrine system aka “master gland”
MODULE 3-3 (9) - Brain
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How do researchers identify the major parts and functions of the brain?
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What are the major parts of the brain, and what behavior is each part responsible?
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How do the 2 halves of the brain operate independently?
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How can an understanding of the nervous system help us find ways to alleviate disease and pain?
Studying the Brain’s Structure and Functions: Spying on the Brain
Electroencephalogram (EEG)
Functional magnetic resonance imaging
Positron emission tomography (PET)
Transcranial magnetic stimulation (TMS)
Central Core: “Old Brain”
Hindbrain contains:
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Medulla: Controls critical body functions, such as breathing and heartbeat
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Pons: Bridge in Hindbrain
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Cerebellum: Part of the brain that controls bodily balance
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Reticular Formation: Extends from medulla through the pons, passing through midbrain and forebrain
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Thalamus: Part of brain located in middle of central core that acts primarily to rely information about the senses
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Hypothalamus: Tiny part of brain, located below the thalamus
Limbic System: Beyond Central Core
Limbic System: Part of the brain that controls eating, aggression, and reproduction
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Includes amygdala and hippocampus
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Plays important role in emotion, learning, and memory, along with hippocampus
Sometimes referred as “animal brain” due to similarities in structures and functions to those of other mammals
Cerebral Cortex: “New Brain”
Responsible for the most sophisticated information processing in the brain
Lobes: 4 major sections of cerebral cortex
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Frontal
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Parietal
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Temporal
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Occipital
Sulci: deep grooves in cortex that physically divides 4 sets of lobes
Motor Area of Cortex
Motor area: Responsible for body’s voluntary movement
Sensory Area of Cortex
Sensory area: Site in the brian of the tissue that corresponds to each sense with the degree of sensitivity related to amount of tissue
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Example: somatosensory area: in parietal lobe; specific locations associated with the ability to perceive touch and pressure in particular location of body
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Auditory area in temporal lobe
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Visual Area in occipital lobe
Association Areas of Cortex
Association Areas: Site of higher mental processes
Example Phineas Gage, railroad worker accident
Aphasia: result from injuries to association areas of the brain, and create problems with language
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Broca’s aphasia
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Wenicke’s aphasia
Neuroplasticity and Brain
Neuroplasticity
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Changes in the brain related to the addition of new neurons that occur throughout the lifespan
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New interconnections between neurons
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Reorganizations of info-porcessions areas
Neurogenesis - Creation of new neurons in certain areas of the brain during adulthood
Specialization of Hemispheres: 2 Brains or 1?
- Brain is divided into 2 roughly mirror-image halves
- Hemispheres: Symmetrical left and right halves of the brain that control the side of the body opposite to their location
- Lateralization: Dominance of one hemisphere of the brain in specific functions
Split Brain: Exploring 2 Hemispheres
Split-brain patients
END OF CHAPTER 3