Chapter 42 Nervous System Flashcards
what makes up the central nervous system?
the brain and spinal cord
what makes up the peripheral nervous system?
sensory and motor neurons
what does the somatic nervous system stimulate?
the voluntary skeletal muscles
what does the autonomic nervous system stimulate?
the involuntary smooth and cardiac muscles, as well as glands
what do the sympathetic and parasympathetic nervous system do?
counterbalance each other in regulation of many organ systems
what is the peripheral nervous system?
all nerves that extend out of spinal cord into body
function of sensory neurons?
afferent neurons that carry impulses to central nervous system
function of motor neurons?
efferent neurons that carry impulses from CNS to effectors(muscles and glands)
function of interneurons?
association neurons that provide more complex reflexes and associative functions(learning and memory)
basic structure of neurons?
-cell body - enlarged part containing nucleus
-dendrites - short, cytoplasmic extensions that receive stimuli
-axon - single, long extension that conducts impulses away from cell body
what is a resting potential?
this is what happens when a neuron is not being stimulated
what is an action potential?
the actual signals that move across an axon, triggered by a threshold change in potential
what are the three phases of action potential?
rising, falling, and undershoot
what makes the membrane potential more positive?
depolarization
what makes the membrane potential more negative?
hyperpolarization
