BIOL 201 Lecture Notes - Lecture 34: Voltmeter, Electromagnetism, Nernst Equation
23 Apr 2016
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Document Summary
Nervous system has inputs: light (photons, sound (air waves, touch (forces, smells/tastes (chemicals) And outputs: movements (muscle contractions, hormones/secretions. Brain is the most densely packed conglomerate of nervous cells (neurons) and glial cells. Golgi staining was used on brain to see individual branching cells (axons/dendrites: very inefficient staining made for good observations. Sensory input (i. e. light into eye), reaches sensitive cells (i. e. Sensory input (i. e. light into eye), reaches sensitive cells (i. e. those on retina) have processes that go to optic nerve that then goes to the brain. In the brain talks to sensory neuron interneuron which does all processing motor neurons that activate a muscle. Propagation of signal down an axon is called an action potential: wave of electricity going down length of axon, 1-10 m/s, triggers release of neurotransmitter at the other end. Glial cells are non-neuronal cells, not electrically excitable but support neurons: astrocytes bring in nutrients and regulate environment, oligodendrocytes wrap around axon to protect it.
