a process in which the nervous system interprets the sensory input and decides what should be done at each moment
the response of the nervous system to integration by activating effector organs (muscle/glands)
central nervous system (CNS)
the integrating and command center of the nervous system; consists of the brain and spinal cord
peripheral nervous system (PNS)
the communication lines that link all parts of the body to the CNS; consists of cranial and spinal nerves
sensory (afferent) division
the subdivision of the PNS that consists of nerve fibers that convey impulses TO the CNS from sensory receptors
motor (efferent) division
the subdivision of the PNS that consists of nerve fibers that transmit impulses FROM the CNS to effector organs (muscles and glands)
somatic nervous system
voluntary nervous system; the subdivision of the motor division that is composed of somatic motor nerve fibers that conduct impulses from the CNS to skeletal muscles
autonomic nervous system
the subdivision of the motor division that consists of visceral motor nerve fibers that regulate the activity of smooth muscles, cardiac muscles and glands
the division of the ANS that activates the body to cope with some stressor (danger, excitement etc); the fight, fright, and flight subdivision
the division of the ANS that oversees digestion, elimination, and glandular function; the resting and digesting subdivision; feed and breed subdivision
star-shaped supporting cells in the CNS that are the most abundant & versitile; assists in exchanges between blood in capillaries and neurons
small ovoid-shaped supporting cells in CNS that have long thorny processes; can transform into macrophages to destroy bacteria, viruses, and damaged cells
supporting cells in the CNS that wrap their cytoplasmic extensions around the nerve fibers, producing insulating covering called myelin sheaths
supporting cells in the PNS that surround neuron cell bodies within ganglia; function still unkown
the suppporting cells in PNS that surround and form myelin sheaths around larger nerve fibers in the PNS
short, tapering branching extensions of motor neurons that serve as receptive or input regions; transmit the nerve impulse towards the cell body
a cone-shaped area of the cell body from which the nerve impulse is triggered to move down the nerve fiber
whitish, fatty, segmented sheath that protects and electically insulates fibers form one another and increases the speed of nerve transmission
regions of the brain and spinal cord containing mostly nerve cell bodies and unmyelinated fibers
neuron with two processes extend for the cell; one is the dendrite, the other is an axon
afferent neruon; transmits impulses from sensory receptors in the skin or internal organs toward or into the central nervous system
efferent neuron; carry impulses away from the central nervous system to the effector organs (muscles or glands)
association neurons; lie between motor and sensory neurons in neural pathways and shuttle signals through CNS pathways where integration occurs
resting membrane potential
the difference in electrical charges on either side of a cell membrane when the cell is at rest, measured in millivolts, inside membrane is more negative than outside, difference in change is ions moving- K+ diffusing out of cell
the process during the action potential when sodium is rushing into the cell causing the interior to become more positive
outflow of positive ions from the nerve cell restores the electrical conditions at the membrane to the polarized, or resting state
when axon is repolarizing, more K+ ions leave the cell, causing the cell to become MORE polarized than before it started
All or None Principle
the law that the neuron either generates an action potential when the stimulation reaches threshold or it doesn't fire when stimulation is below threshold
pathway for a simple nervous reaction: knee jerk, sensory receptor, sensory neuron, motor neuron, and effector that are involved in a quick response to a stimulus
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 cleft.
a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential(impulse)
a neurotransmitter that enables learning and memory and also triggers muscle contraction
neurotransmitter that influences voluntary movement, attention, alertness; lack of dopamine linked with Parkinson's disease; too much is linked with schizophrenia
receptor, efferent neuron, integration center, afferent neuron, effector
What is the path of a simple spinal reflex?
What is the period after an initial stimulus when a neuron is not sensitive to another stimulus?
Action potentials are moving too slowly to communicate
Why is nerve function impaired when myelin surrounding an axon is damaged?
central nervous system
Which branch of the nervous system contains the major organs of the nervous system?
peripheral nervous system
Which branch of the nervous system connects the brain and spinal cord to other organs?
nerve cell bodies and glial cell bodies
What is the gray matter of the central nervous system composed of?
True or False--Electrical nerve stimulation is a more effective anesthesia than chemical inhibitors.
Peripheral Nervous System
The following are characteristics of which branch of the nervous system? carries messages to and from the brain and spinal cord, contain somatic and autonomic divisions, contain motor and sensory nerve cells.