P a g e | 1CHAPTER 2 PSYC 1000 SEC 13 2.1 Biology and Behavior - BIOLOGICAL PSYCHOLOGISTS: o Study the links between our biology and behavior 2.2 Neural Communications- Animals and Humans share similar “operating systems” 2.2.1 Neurons- NEURONS:o A nerve cell; the basic building block of the nervous systemo Active neurons require glucose the way a car requires fuel  Cell body - Life support center Dendrites - Receive messages from other cells  Axon - Passes messages away from the cell body to other neurons, muscles, or glands Neural impulse - Action potential (a neural impulse; a brief electrical charge that travels down an axon)- Electrical signal traveling down the axon Terminal branches of axon - Form junctions with other cells  Myelin sheath - covers the axon of some neurons and helps speed and neural impulses- GLIAL CELLS :o Cells in the nervous system that support, nourish, and protect neuronso They also may play a role in learning and thinking- ACTION POTENTIAL o Neuron stimulation causes a brief change in electrical charge. If strong enough this produces depolarization and an action potentialo This depolarization produces another action potential and little farther along the axon. Gates in this neighboring area now open, and charged sodium atoms rush it. A pump in the cell membrane (the sodium/ potassium pump) transports the sodium ions back out of the cello As the action potential continues speedily down the axon the first section has now complete recharged. - Threshold = minimum intensity- WHEN A NEURON FIRES AN ACTION POTENTIAL THE INFO TRACELS THROUGH THE AXON, THE DENDRITES AND THE AXONS TERMINAL BRANCHES, BUT NOT IN THAT ORDER. PLACE THESE THREE STRUCTURES IN THE CORRECT ORDER o Dendrites, Axon, Axon’s terminal branches- How does our nervous system allow us to experience the difference between a slap and a tap on the back o Stronger stimuli (the slap) causes more neurons to fire and to fire more frequently than what happens with the weaker stimuli(the tap) 2.2.3 How Neurons Communicate - Sir Charles Sherrington o SYNAPSE:P a g e | 2 The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; The tiny gap at this junction is called the synaptic gap or synaptic cleft- NEUROTRANSMITTERS :o Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron,neu-rotransmitters travel across the synapse and bind to receptor sites on receiving neuron, thereby influencing whether that neuron will generate a neural impulse. Cross gaps and bind to the receptor sites on the receiving neuron Action potentialNeurotransmittersexcited atoms in receiving atom reuptake- WHAT HAPPENS IN THE SYNAPTIC GAP? o Neurons send neurotransmitters across this tiny spce between ones neuron’s terminal branch and the next neurons dendrite or cell body2.2.4 How neurotransmitters influence us - A neurotransmitter affects specific behaviors and emotions o Acetylcholine  Enables muscle action, learning and memory If blocked we are paralyzed o Dopamine  Influence movement, learning, attention, and emotion- Too little dopamine = Parkinson’s disease - Too much dopamine = schizophrenia o Serotonin  Affects mood, hunger, sleep, and arousalo Norepinephrine  Helps control alertness and arousalo GABA  A major inhibitory neurotransmitter Low  seizures, tremors, and insomnia o Glutamate  A major excitatory neurotransmitter; involved in memory- Candace pert and Solomon Snyder o Morphine - Naturally occurring opiates o ENDORPHINS: Natural, opiate like neurotransmitters linked to pain control and to pleasure- Agonist drugso Mimics neurotransmitter functioning  Black widow spider bite- Antagonist drugso Block a neurotransmitter’s functioning  Botulin or Botox  Paralyzing the muscles in the place where its being injected 2.3 The Nervous System - The Nervous system is the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems. o CENTRAL NERVOUS SYSTEM  Brain  Spinal chordP a g e | 3 The body’s decision makero PERIPHERAL NERVOUS SYSTEM  The sensory and motor neurons that connect the central nervous system to the rest of the body Body’s sensory receptors, muscles and glands- AUTONOMIC o Controls self-regulated action on internal organs and glands Sympathetic (arousing) Parasympathetic (calming)- SOMATIC o Controls voluntary movements of skeletal muscles Info travels through the nervous system through three types of neuronso Sensory neurons  Carry incoming info from the sensory receptors to the brain and spinal cordo Motor neurons  Messages from the brain and spinal cord  muscles and glandso Interneurons  Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs  Least likely to worry about if you lost 100,000 of them 2.3.1 The Peripheral Nervous system- Canial nerves and spinal nerves - Communication lines btween the cns and rest of the body SOMATIC NERVOUS SYSTEM:o Enables voluntary control of out skeletal muscles AUTONOMIC NERVOUS SYSTEMo Controls our glands and the muscles of our internal organs Sympathetic nervous system - Arouses and expends energy - Accelerate your heartbeat- Raise your blood pressure- Slow digestion- Raise blood sugar - Cool perspiration - Alert and ready for action Parasympathetic - Conserving energy as it calms you- Decreasing heartbeat - Lowering blood sugaro They both work together to help maintain homeostasis2.3.2 The Central Nervous System- Brain and spinal cord - Integrative and control centers - Neural networks  the brains neurons clustered - REFLEXES o A simple, autonomic, response to a sensory stimulus, such as the knee-jerk response- A simple spinal reflex pathway is composed of a single sensory neuron and a single motor neuron- Pain reflex circuitP a g e | 4o Your hand will jerk away from the fire before you can feel the pain 2.4 The Endocrine System - THE ENDOCRINE SYSTEMo The body’s “slow” chemical communication system; a set of glands that secrete hormones into the blood stream. - HORMONES o Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues. Sex  Food 