M1 PSC 131 - Chapter 3 study questions: 1. list the main...

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Chapter 3 study questions: 1. list the main parts of a neuron and describe the function of each: a. cell body: contains the nucleus b. axon: long fibers that conduct nerve impulses towards the many other neurons with which each neuron connects. Many neurons have axons that are covered by protective and nutritive cells called the myelin sheath made of glial cells. c. Dendrites : the branching structures that receive info from incoming nerve fibers of other neurons. 2. describe the way a neuron communicates to other neurons using the sodium potassium pump. a. Sodium potassium pump ejects 3 sodium molecules from the cell for every 2 potassium molecules it allows into the cell. When a neuron is stimulated, the electrical potential changes across the cell. b. Depolarization: a change in electrical potential from the resting potential toward 0 mV and beyond. c. Hyperpolarization: a change toward an even more negative potential. d. Action potential: an abrupt change in a cells state aka neural spike. e. Refractory period: the period of hyperpolarization following a spike. During this time, the neuron is much more difficult to excite. f. Resting potential: about -70 mV. Its when a neuron is unstimulated or at rest, the inside is electrically negative with respect to the outside. 3. what is the main way in which sensory receptors communicate with other neurons? What about interneurons? a. Sensory neuron: conducts info about the outside world to other neurons. b. Interneuron: conducts info btwn neurons: c. Motor neuron: conducts nerve impulses from the central nervous system outwards to the muscles. 4. list some differences between the microscopic and macroscopic approaches to the study of the nervous system. Microscopic macroscopic the behavior of individual neurons in known sensory pathways or brain regions can be recorded. The functioning of larger brain regions and neural systems is studied. 5. draw and label the man structures of the human eye: a. sclera: the outer covering, which is seen as the “white” of the eye, is a strong elastic membrane. b. cornea: the front of the eye where the sclera bulges forward to form a clear, domelike window. It serves as a simple fixed lens that begins to gather light and concentrate it so that it will eventually form a sharp image on the rear interior surface of the eye. It allows for the reception of light from a region slightly behind the observer. c. aqueous humor: watery fluid between the cornea and the lens. d. vitreous humor: a clear jellylike substance that fills the main chamber of the eye. e. iris: colored membrane surrounding the pupil. Iris color is genetically determined. Function is to control the amount of light entering the eye. f.
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M1 PSC 131 - Chapter 3 study questions: 1. list the main...

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