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Neurons and the nervous systems. October 2010. Q1 - Parts of the neuron. Dendrites Cell body Axon Axon segments Axon terminals Synapse Myelin sheath. How neurons work. Neurons are cells - with walls, nucleus, etc Q2 - Neurons receive information
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Neurons and the nervous systems October 2010
Q1 - Parts of the neuron • Dendrites • Cell body • Axon • Axon segments • Axon terminals • Synapse • Myelin sheath
How neurons work • Neurons are cells - with walls, nucleus, etc • Q2 - Neurons receive information • Receive both excitatory and inhibitory messages • Q3 The neuron exceeds threshold when
What does fire mean? • By “firing,” the neuron transmits a signal to either the receptor of another neuron or to some other body structure (eg, muscles) • Q4 - When neurons fire, it is “all or nothing”. • When it “fires,” it sends neurotransmitters into the synapse (or synaptic gap) where other neurons can receive them
Neurotransmitters Q5 • They are chemical compounds that are used in the brain and the body. • Most are associated with one or more physical or brain functions. • Excess or deficit of certain NTs is associated with different psychological and physical diseases - schizophrenia, Parkinson’s
Q6 - An action potential • A neuron fires! • www.sheatech.net/axon.swf • Refractory phase
After NTs released • See p 57 - diagram • Receptor sites on next neuron • Reuptake – Q7 • Note - NTs are not used up or destroyed in the synapse
NTs you should know • Q8 - Dopamine • Acetylcholine (Ach) • Q9 - Serotonin • Norepinephrine • Q10 - GABA • Glutamate • Q11 - Endorphins
Q12 Nervous system hierarchy P… C…. B.. SC S… A.. P S
Kinds of neurons • Q13 - Sensory neuron - afferent • Motor neuron - efferent • Q14 - Interneuron (and reflexes) • Mirror neurons
Misc facts • Q15 - Neural networks • Q16 - Antagonist / agonist • Q17 - Nerve - a nerve is a bundle .. • Q18 – Spinal cords • Graphic on pg 62
Endocrine system Glands, hormones and behavior
Endocrine system • _____ messenger system Q19 • Controlled by ____________ which is controlled by ________________ • Hormones • Q20 • norepinephrine
Controlling structures • Hypothalamus- Q21 • Controls _________________ • Produces _________________ • Other brain functions ….. • Pituitary –Q22 • Produces both _________________________ • Controls ______________________________
Adrenal (“next to kidneys”) Q23 • Arousal • Produces ________________________ • Fight or flight • Pancreas Q24 • Produces • Produces • Thyroid controls ___________ Q25 • Pineal - melatonin - bio rhythms Q26
Sex and the endocrine system • Ovaries Q27 • Testes • Primary sex characteristics • Secondary sex characteristics
Q28 - Brain research • MRI • fMRI • CAT scan • PET scan • Ablation / lesion • EEG
Brainstem – Q29 • Medulla - • Pons - • Reticular Formation -
Thalamus – Q30 • Thalamus - the sensory switchboard
Cerebellum – Q31 • Non-verbal • All non-conscious
Limbic system – Q32 • Hypothalamus • Amygdala • Hippocampus • Pituitary gland
Cerebral cortex • Assume many parts of the brain are involved in most mental processes • Temporal lobes are not the only parts involved in hearing, right brain / left brain, etc • We will identify major functions of different parts - not necessarily all their functions, nor all the parts of the brain involved in different functions
Structure • Glial cells - Q33 • 2 hemispheres • Lobes – Q34 • Cortexes - motor, sensor • Association areas
Cortexes – Q35 • Sensory cortex • Motor cortex
Lobes – Q36 • Frontal • Parietal • Occipital • Temporal
Association areas • Q37 • Is it true that we use only 10% of our brains?
Q38 - Reading aloud - see pg 81 • Text to visual cortex as graphics • Angular gyrus interprets picture as auditory code • Wernicke’s area interprets auditory code as language • Broca’s area controls speech using the motor cortex • Motor cortex controls lips, tongue, etc
Brain plasticity • Q39 • What do we mean by plasticity?
Corpus callosum • Q40 • How is the corpus involved in seizure treatment?
Split brains • Q41 - HE * ART experiment • Q42 – Who was Phineas Gage? • Q43 - right side functions • left side functions
Nature vs nurture Or what the heck is heritability?
Q44 - Behavioral genetics • The study of how genes and environment interact to affect our behavior, personality • Heritability - the extent to which differences between groups of people can be attributed to genetics
Q45 - Genes • Genome • Chromosomes • Genes • DNA
Twins and adoptees – Q46 • Q47 - MZ’s and DZ’s - monozygotes and dizygotes • MZ’s share 100% of genetic material • DZ’s share 50% • All siblings share 50% (on average) • Adoptees share environment with adopted family • MZ’s and DZ’s may not share environment
Q48 - Shared environment • Assumption is that living in the same home with same parents and same general environment will cause children to be similar • And different from kids from another family
Shared environment • Seems reasonable • Except it doesn’t seem to happen
Evidence • Similarities among MZA’s, MZ’s, DZ’s, DZA’s • Low correlations between traits of adopted child and adopted parents • Multiple adoptees in one family don’t become similar • Large differences among natural siblings
Why do siblings differ? • They are different genetically • How “shared” is the shared environment? • Pre-natal influences • Birth order effects? • Age and sex of older sibs • Unique experiences - injury, illness
Generally it appears that the higher the genetic relatedness, the higher the correlation of IQ scores • Appears that IQ has a high degree of heritability
How about schizophrenia? • Predict: • Will both identical twins be schizophrenic? • How about fraternal twins? • Child of schizophrenic parents? • Sibling of schizophrenic?
Once again the closer the genetic relationship, the higher concordance • That argues for a high level of heritability - that is, we can explain the differences by genetics
Can’t we argue that the more we share environment, the closer our IQ scores will be?