1. Parts of the Nervous System Neurons – communication specialists, transmit signals to, from, and within CNS. Neurons – communication specialists, transmit signals to, from, and within CNS. ~ apprx. 100 billion in human brain ~ apprx. 100 billion in human brain ~ building blocks of CNS ~ building blocks of CNS ~ Neurons can regenerate and reproduce themselves ~ Neurons can regenerate and reproduce themselves 3 parts to Neuron: 3 parts to Neuron: Dendrites – message receivers Dendrites – message receivers Cell Body – contains biochemical machinery to keep neuron alive Cell Body – contains biochemical machinery to keep neuron alive Axon – sends messages away from cell body Axon – sends messages away from cell body –Myelin Sheath – fatty material which covers axons; keeps signals from other neurons from interfering with each other. Loss of myelin causes loss of sensation, paralysis, weakness Loss of myelin causes loss of sensation, paralysis, weakness Action Potential – electrical pulse Action Potential – electrical pulse Refractory Period – short recovery period between firing. Refractory Period – short recovery period between firing.

2. Central Nervous System Functions – receives, processes, interprets and stores incoming information; sends out information to muscles, glands, internal organs. Functions – receives, processes, interprets and stores incoming information; sends out information to muscles, glands, internal organs. Parts – brain and spinal cord Parts – brain and spinal cord Peripheral Nervous System Functions Functions –Sensory nerves – bring input from skin, muscles and organs. –Motor nerves – carry output to muscles, glands and organs Somatic nervous system Somatic nervous system Nerves connected to sensory receptors Nerves connected to sensory receptors Nerves connected to skeletal muscles – voluntary actions Nerves connected to skeletal muscles – voluntary actions Autonomic nervous system Autonomic nervous system –Functions – regulates blood vessels, glands, organs –Biofeedback – helps people control autonomic responses Sympathetic – mobilizes the body for action Sympathetic – mobilizes the body for action Parasympathetic – enables body to conserve and store energy. Parasympathetic – enables body to conserve and store energy.

3. Peripheral Nervous System Nuclei – CNS clusters of neuron cell bodies Nuclei – CNS clusters of neuron cell bodies Fiber Tracts (Pathways) – bundles of axons Fiber Tracts (Pathways) – bundles of axons Nerves – made of bundles of neuron fibers Nerves – made of bundles of neuron fibers –43 pairs of peripheral nerves –1 nerve of each pair to left side & to right side of body. –Most come out of the spinal cord –12 are in the brain called cranial nerves. Reflexes – incoming signal is “reflected” back out Reflexes – incoming signal is “reflected” back outNeurotransmitters Chemical created in synapses to carry signals from neuron to neuron. Chemical created in synapses to carry signals from neuron to neuron. –If neurotransmitters don’t get to correct neuron, message doesn’t get carried out. Three Classes of Neurotransmitters: Small Molecules, Peptides, Gases Three Classes of Neurotransmitters: Small Molecules, Peptides, Gases Small Molecules Small Molecules –Serotonin – affect sleep, appetite, sensory perception, mood, temperature regulation. –Dopamine – affects voluntary movement, learning, memory, emotion. –Acetylcholine – affects muscle action, cognitive function, memory, emotion –Norepinephrine – affects learning, waking from sleep, memory, dreaming, heart rate due to stress. –GABA – the major inhibitory neurotransmitter in the brain. –Glutamate – strengthens synaptic connections – easier to send messages. –High and low levels of these neurotransmitters can have harmful affects.

4. Peptides Peptides –Endorphins Any neurotransmitter that can bind to same receptors stimulated by opiates. Any neurotransmitter that can bind to same receptors stimulated by opiates. Natural opiates; reduce pain, promote pleasure & bring on sleep in high doses. Natural opiates; reduce pain, promote pleasure & bring on sleep in high doses. Limit or prolong effects of the neurotransmitters Limit or prolong effects of the neurotransmitters Effect appetite, blood pressure, mood, learning, memory, sexual activity Effect appetite, blood pressure, mood, learning, memory, sexual activity Levels increase when animal or person is afraid or stressed; needed for survival. Levels increase when animal or person is afraid or stressed; needed for survival. Endorphins levels increase when given affection by someone else. Therefore, people tend to seek out affection or love. Endorphins levels increase when given affection by someone else. Therefore, people tend to seek out affection or love. Gases Gases –Nitric Oxide and Carbon Dioxide Released by neurons & affects chemical reactions Released by neurons & affects chemical reactions Key to diverse functions; sexual performance to formation of memories Key to diverse functions; sexual performance to formation of memories

5. Endocrine System –Regulates growth, energy consumption, sexual behavior, & readies body for action. Hormones Hormones –Originates in endocrine glands –Released directly into blood stream. –Aids digestion, regulates metabolism, promotes bodily growth. –Some hormones are more interesting to psychologists then others: Melatonin Melatonin –Promotes sleep –Coordinates body rhythms, ex. Sleep cycle Adrenal Hormones Adrenal Hormones –Involved in emotion and stress –Levels affected by pain, temperatures, physical exercise, injury, caffeine & nicotine. –Get body ready for action. –Adrenal hormones enhance memory as long as levels are normal. Sex Hormones Sex Hormones –Androgens and Testosterone – male hormones –Estrogens – female hormones –Progesterone – prepares and maintains uterine lining for fertilized egg.

6. The Brain The Hindbrain Continuation of spinal cord; reflex & feedback system are important Continuation of spinal cord; reflex & feedback system are important Vital autonomic functions are controlled here, in the Medulla Vital autonomic functions are controlled here, in the Medulla Reticular Formation in Hindbrain to Midbrain Reticular Formation in Hindbrain to Midbrain –Involved in arousal & attention Cerebellum Cerebellum –Involved in both physical & cognitive agility –Well-rehearsed movements, language, abstract thinking, finely coordinated movements.

7. The Brain The Midbrain Midbrain & hindbrain makeup brainstem. Midbrain & hindbrain makeup brainstem. Smooth movements Smooth movements The Forebrain Complex aspects of behavior & mental life. Complex aspects of behavior & mental life. Cerebral Cortex is its outer surface. Cerebral Cortex is its outer surface. Thalamus – processes & makes sense of pain & sensory information Thalamus – processes & makes sense of pain & sensory information Hypothalamus Hypothalamus –regulates hunger, thirst & sex drives –Connected to autonomic system & other parts of brain. Amygdala Amygdala –Links different sensory info in memory. –Role in fear & connecting emotion to sensation. Hippocampus Hippocampus –Emotions & formation of new memories –Shrinks as you get older, 40% smaller in Alzheimer suffers

8. The Brain Cerebral Cortex Analyzes info from senses Analyzes info from senses Controls voluntary movement Controls voluntary movement Abstract thinking & other complex behaviors Abstract thinking & other complex behaviors Corpus Callosum Connects the two hemispheres of brain Connects the two hemispheres of brain Sensory Cortex Receives info from different senses Receives info from different senses Makes up for lost senses with other senses. Makes up for lost senses with other senses. Motor Cortex Controls voluntary movement for specific parts of the body. Controls voluntary movement for specific parts of the body.Plasticity Ability to strengthen & create new connections Ability to strengthen & create new connections

9. Right side Controls left side of the body Controls left side of the body Some language ability Some language ability Solves problems requiring spatial-visual abilities. Solves problems requiring spatial-visual abilities. Excels reading maps or follow dress patterns Excels reading maps or follow dress patterns Excels in facial recognition & reading facial expressions. Excels in facial recognition & reading facial expressions. Recognizes non-verbal sounds Recognizes non-verbal sounds Learning style is more intuitive & holistic Learning style is more intuitive & holistic Active in creation & appreciation of art & music Active in creation & appreciation of art & music

10. Left side Process language in the left hemisphere Process language in the left hemisphere Used with logical, symbolic, & sequential tasks Used with logical, symbolic, & sequential tasks Good at learning things. Good at learning things. Tries to explain actions & emotions, especially non-verbal. Tries to explain actions & emotions, especially non-verbal. Speech ability is stronger Speech ability is stronger 2 hemispheres cooperate naturally and neither is dominant over the other. 2 hemispheres cooperate naturally and neither is dominant over the other. They both have their talents and they are used when needed. They both have their talents and they are used when needed.

11. What happens when they are unable to communicate with each other? What happens when they are unable to communicate with each other? –Ronald Myers & Roger Sperry split the 2 hemispheres of several cats’ brains and severed the eye nerves that lead to the brain. Result: Result: –Trained cats to perform tasks with one eye covered –Cats were only able to perform task learned while right eye was uncovered when the right eye was uncovered and vice-a-versa. Explanation: since two sides of brain cannot communicate with each other then they can’t share learned information. Explanation: since two sides of brain cannot communicate with each other then they can’t share learned information.