neuroscience and behavior t/f: we only use 10% of our brains: lucy t/f: we only use 10% of our...
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Neuroscience and Behavior
T/F: We only use 10% of our brains: Lucy
It’s all about the body!crash course
Neural Communication
Neuron – a nerve cell; “building block” of the nervous system Icons of Science
Neuroanatomy(include glial cells)
Khan Academy, stop @ 3:30
Neuroanatomy
• Synapse – the junction (space) between the axon of one neuron and the dendrite of another
• Neurotransmitter – chemicals that carry messages across the synapse from one neuron to another
How a Neuron FiresKhan: stop @ 4:45
• an electrochemical process– Electrical inside the neuron;
chemical outside the neuron (neurotransmitters).
• called an action potential• an “all or nothing” process– like a gun– greater intensity of stimulus does
not equal faster/more intense firing; greater stimulus can mean more neurons firing or more frequent firing
Action Potential1. Resting Potential - the neuron is ready
to fire 2. Reaches its threshold , then fires based
on the all-or-none response3. Polarization Depolarization
a) opens up portals in axon letting in positive ions (Sodium) which mix with negative ions (Potassium) that are already inside the axon
b) process continues down axon to the axon terminal
4. Terminal buttons convert electrical charge into chemical response (neurotransmitter) and sends message to next neuron, across the synapse
Action Potential
The Role of Neurotransmitters
•Excitatory - neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or “fire”• Inhibitory - neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential or “fire”
SPECIFIC NEUROTRANSMITTERS
Acetylcholine (ACh)• vital role in
movement and memory
• too much – muscle contractions, convulsions– some spider venoms
cause floods of ACh• too little – immobility,
extreme lethargy– Botulin causes
paralysis by blocking its release
• Undersupply of ACh has been linked to Alzheimer’s disease
Dopamine
• deals with movement, learning, attention & emotion
• lack of dopamine has been linked to Parkinson’s Disease
• too much has been linked to Schizophrenia
Serotonin
• involved in mood control, hunger, sleep / arousal
• lack of serotonin has been linked to clinical depression (Prozac and other antidepressants raise serotonin levels)
Endorphins• “endogenous
morphine”• involved in pain
control• most addictive
drugs work with endorphins
Neurotransmission Drugs• Agonists - mimics / blocks reuptake /
excites• Antagonists - prevents release / blocks /
inhibits
Types of NeuronsKhan;start @ 4:50
• Efferent (Motor) Neurons– info to body parts for
movement
• Interneurons– info within central nervous
system
• Afferent (Sensory) Neurons– info to CNS from body parts
• Remember… S.A.M.E.
A Neural Chain
A Neural Chain
A Neural Chain
A Neural Chain
The Nervous Systemcrash course
Khan
Central Nervous System
• brain and spinal cord• CNS
Peripheral Nervous System
• all nerves that are not encased in bone
• everything but the brain and spinal cord
• divided into two categories– somatic– autonomic
Somatic Nervous System
• controls voluntary muscle movement
• uses motor (efferent) neurons
Autonomic Nervous System
• controls the automatic functions of the body
• divided into two categories– sympathetic– parasympathetic
Sympathetic Nervous System
• “Fight or Flight” response
• automatically accelerates heart rate, breathing, dilates pupils, slows down digestion
Parasympathetic Nervous System
• automatically calms the body down after a stressful event
• heart rate and breathing slow down, pupils constrict, and digestion speeds up
• think, “parachute”
Reflexes
• normally, afferent neurons spine brain & brain sends orders for movement efferent neurons
• some reactions occur when sensory neurons reach just the spinal cord & spinal cord sends orders
Neural NetworksHow much of our brain do we actually use?
• interconnected neurons• regular connections or
routes of communication for different tasks, processes, etc.
• body/brain “learns” networks over time
• “muscle memory” in sports (“practice makes permanent”)
brain rap
Ways to Study the Brain
• Case Studies / Clinical Observation– Accidents (i.e. –
Phineas Gage)– Diseases /
Disorders
Invasive Exploration
• Lesion - a natural or man-made destruction of brain tissue• Electrical
Probing• Psychosurgery
Less Invasive Methods
• Electroencephalogram (EEG)
• Computerized Axial Tomography (CAT Scan / CT Scan)
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography (PET)
• Functional MRI (fMRI)
The BrainPinky & the Brain
• made up of…– neurons – glial cells (or glia -
support neural cells by insulating them, removing waste, etc.)
– connective tissues– cerebrospinal fluid
• can be divided into three major sections: hindbrain, midbrain, forebrain
Brain Structuresbrain mneumonics
• Be familiar with functions/roles.
• Location / ability to label might be helpful, but not required.
Our Super Brain!
For your assigned brain area:-Where is it located?-What is it’s main functions?-Create a superhero or supervillain with extra strength in this part of his or her brain that gives them their super powers (be sure to include what his /her power is). .
Brainstem• Pons - involved in sleep,
arousal, facial recognition• Medulla Oblongata
located just above the spinal cord
involved in the control of heart rate, blood pressure, respiration.
• Reticular Formation - arousal and ability to focus attention
Cerebellum
• coordinates voluntary muscle movements
• balance/coordination• injury = difficulty
walking, keeping balance, shaking hands, etc.
Thalamusswitchboard example
• Receives sensory information and sends them to appropriate areas of forebrain.
• Like a switchboard.
• Everything but smell.
Limbic System#24
• EMOTIONAL CONTROL CENTER of the brain.
• Made up of Hypothalamus, Amygdala and Hippocampus.
Hypothalamus• Pea sized in brain,
but plays a not so pea sized role.
• Body temperature• Hunger• Thirst• Sexual Arousal
(libido)• Endocrine System
Hippocampus and Amygdala
• Hippocampus is involved in forming new memories.
• Amygdala is vital for our basic emotions.
Cerebral Cortex
• Top layer of our brain.
• Contains wrinkles called fissures.
• The fissures increase surface area of our brain.
• Laid out it would be about the size of a large pizza.
Hemispheres
• Divided into a left and right hemisphere.
• Contralateral controlled- left controls right side of body and vice versa.
• Brain Lateralization.
Split-Brain Patients
• Corpus Collosum attaches the two hemispheres of cerebral cortex.
• right & left sides working together?
• When removed (usually b/c of severe seizures) you have a split-brain patient. #5
Areas of the Cerebral Cortex
• Divided into eight lobes, four in each hemisphere (frontal, parietal, occipital and temporal).
• Any area not dealing with our senses or muscle movements are called association areas.
Frontal Lobe
• Deals with planning, maintaining emotional control and abstract thought.
• Contains Broca’s Area.
• Broca’s Aphasia.• Contains Motor
Cortex.
Parietal Lobes
• Located at the top of our head.
• Contains the somato-sensory cortex.
• Rest are association areas (intelligence!).
Occipital Lobes
• In the back of our head.
• Handles visual input from eyes.
• Right half of each retina goes to left occipital lobe and vice versa.
Temporal Lobes
• Process sound sensed by ears.
• Not lateralized.• Contains
Wernicke’s area.• Wernicke’s
Aphasia.
Build a Brain!
Using the materials provided build a brain and label the following areas:-Frontal Lobe -Temporal Lobe-Parietal Lobe -Occipital Lobe-Cerebellum -Brain Stem
Also include one specific function of that area in your label.Then on a separate piece of paper, write down how each part of your brain is engaged in this activity.
Brain Plasticity# 7
• ability of our brains to form new connections (repair itself) after being damaged
• the younger you are, the more “plastic” your brain is
The Endocrine Systema system of glands that secrete
hormones into the bloodstreamsimilar to nervous system,
except hormones work a lot slower than neurotransmitters
Neurotransmitters
Hormones
Endocrine System
• System of glands that secrete hormones.
• Controlled by the hypothalamus.
• Ovaries and Testes.• Adrenal Gland• Epinephrine-energy
boost (adrenaline)
Common Hormones That Influence Behavior
Hormone Where? What does it do? Too much?
Not enough?
Epinephrine(Adrenaline)
Adrenal gland
-stress management-fight or flight
Melatonin Pineal gland
-regulated circadian rhythm (sleep/wake cycle)
Oxytocin Pituitary gland
-romantic attraction -bonding (romantic, parental)-regulates fear and anxiety-increased empathy
Testosterone Testes (m)Ovaries (f)
-aggression-libido-encourages risk taking
Estrogen Ovaries (f)Testes (m)
-regulates mood (f)-regulates compulsive behavior (m)-libido (f)
Nervous System v. Endocrine System
Nervous System Endocrine System
Signal
Transmission
Speed
Duration
Compare and Contrast the Nervous and Endocrine Systems using the following chart:
Nervous System Endocrine System
Signal Nerve impulses Hormones
Transmission Along neural networks
Carried in the blood stream
Speed Super fast- nearly instantaneous
Much slower
Duration Fraction of a second
Much longer lasting
• hold your stomach!
• So what’s the REAL significance of this chapter??