Neurons & Nervous System Development – Genes; ~25,000 in a fertilized egg Structure - ~ 3 lbs; fuel = glucose glial cells (support; insulation) Neurons (brain cells) Some Repair- no regrowth in neurons except dendrite extensions

What’s in the Central Nervous System ? Central Nervous System (CNS) Brain – (Made up of neurons) & Spinal Cord What comprises a Neuron? (refer to diagram) Cell body – Dendrites – Axon – Myelin Sheath - End bulbs – Synapse –

Neuron

Peripheral Nervous System Nerves outside the Brain & Spinal cord Can regrow, regenerate & reattach What is the Peripheral Nervous System?

What do Neurotransmitters do? Excitatory Open up the chemical gates in organs/cells increase the response Inhibitory Block the chemical gates – decrease the organ response Endorphins – Natural pain killers ALL or NONE Law – transmission occurs from start to end in a neuron

What are Reflex Responses? Unlearned, involuntary, protective Afferent – Sensory Attach to the Spinal Cord Efferent – Motor Exit from the Spinal Cord

What is Phantom Limb Phenomena? Feeling Sensations from an amputated limb ? Stump Nerves? ? Spinal Cord? ? Brain? (Apparently images & sensations are stored there)

How do drugs affect neurons? Blocking reuptake of neurotransmitter Blocking receptors Mimicking neurotransmitters

Should Fetal Tissue Transplants be Allowed? Allows growth of neurons in damaged areas Parkinson’s disease – motor neuron recovery Alzheimers Multiple Sclerosis Cells removed from aborted fetuses

The Brain – Structure / Function Anamolies: Which affect brain… Anencephaly Hydrocephaly Trisomy 21 – Down’s Syndrome Fragile X syndrome – pinched X Epilepsy / Stroke

How does the Theory of Evolution Relate? Basis for much of psychology due to Darwin’s influence How is behavior, growth, development adaptive or functional for the individual and/or species

How do we look at the brain? MRI (Magnetic Resonance Imaging) Radio frequencies Structure PET Scan -Positron Emission Topography Radioactive absorption in areas Functioning

What are the branches of the Peripheral Nervous System? Somatic – Voluntary Includes afferent and efferent nerves Autonomic – Involuntary (Automatic) Sympathetic – Parasympathetic –

How does the Peripheral Nervous System Work? Fight or Flight Response – triggered by Sympathetic system Bodily reaction to threatening situation Homeostasis –equilibrium

Autonomic Nervous System

What’s at the front of our brain? Frontal Lobes Most evolved Aspects of Emotion Executive Functions Motor Cortex **-Voluntary motor functions Broca’s area – Production of language

What’s at the top of our brain? Parietal Lobes Sensory information; temp & pain Somatasensory Cortex Information on touch, limbs, pain & temperature, object recognition & remembering ** Contralateral – one side of brain controls opposite side of body

What’s at the side of our brain? Temporal Lobes Hearing/speaking words/ Writing Primary Auditory Cortex – Auditory association area – Wernicke’s area – understanding speech and speaking coherently

What’s at the back of our brain? Occipital Lobes Colors, Recognizing objects, animals, people Primary Visual Cortex – Visual Association Area –

What is in the Hindbrain? Cerebellum – “little brain” Co-ordinated motor movement Pons - Sleep Medulla – vital functions

Is there a correlation between Brain Size & Intelligence ? Racial myths – only used confirming data leading to biases Density, not structural size appears important

Are there Hemispheric Differences ? Left Side of the Brain Verbal Language, Math, Analytical (pieces) Right Side of the Brain Nonverbal, Spatial, Holistic (combining parts into meaningful whole) Split-brain video clip