Psych-100 textbook outline unit 2

Psych-100 textbook outline unit 2 - Andrea Chin's Psych-100...

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Andrea Chin’s Psych-100 Textbook Outline: Unit 2: Chapter 5: The Neural Control of Behavior ( 9/15/06-9/19/06) -The brain makes up about 2% of an average person’s body weight but 20% of a person’s metabolic energy. -The human brain contains roughly 100 billion neurons and roughly 100 trillion synapses, or points of communication between those neurons. - central nervous system : brain and spinal cord - peripheral nervous system : the entire set of nerves that connect the brain and the spinal cord to the sensory organs, muscles and glands - nerve : bundle of the axons of many neurons within the peripheral nervous system - sensory neurons : carry information from sensory organs into the CNS - motor neurons : carry messages out from the CNS to operate muscles and glands - interneurons : relay messages b/w the neurons of the CNS; vastly outnumber the other 2 - cell body : cell nucleus and other basic machinery common to all bodily cells - dendrites ; thin, tube-like extensions that receive input to the neuron -motor neurons and interneuron dendrites: extend directly off the cell body; increase the surface area and allow for receipt of signals from many other neurons -sensory neuron dendrites: extend from one end of the axon into a sensory organ - axon : another kind of thin, tube-like extension to carry messages to other neurons or, in the case of motor neurons, to muscle cells - axon terminal : release chemical transmitter molecules onto other neurons or, in the case of motor neurons, onto muscle cells or glandular cells - myelin sheath : special non-neural cell casing surrounding some neurons’ axons - action potentials : all-or-none firing off impulses -In motor neurons and interneurons they’re triggered at the junction between the cell body and the axon and travel rapidly down the axon to the axon terminals. -In sensory neurons they’re triggered at the dendritic end and travel through or past the cell body to the axon terminals. -Each action potential produced by a neuron is the same strength as any other action potential produced by that neuron & retains full strength all the way down the axon. -By varying its rate of action potentials, a neuron varies the strength of its effect on other neurons or muscle cells. -More negatively charged particles exist inside the cell than outside. -Soluble protein molecules have negative charges and exist only in the intracellular fluid. -Potassium ions (K+) are more concentrated in the intracellular than extracellular fluid. -Chloride ions (Cl-) are more concentrated in the extracellular than intracellular fluid. - resting potential : charge (A-) across the membrane of an inactive neuron -Potassium ions can diffuse out through the semipermeable membrane, -There’s a surplus of positive charges outside the cell and a deficit of positive charges inside, which means that the resting membrane has an electrical charge across it of ~70 mV with the inside negative compared to the outside. -Two forces drive sodium ions into the cell when thousands of tiny channels are open:
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This note was uploaded on 02/27/2008 for the course PSYC 100 taught by Professor Madigan during the Fall '07 term at USC.

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Psych-100 textbook outline unit 2 - Andrea Chin's Psych-100...

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