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68wm6 nervous system
Question | Answer |
---|---|
afferent neurons | sensory neurons |
arachnoid mater | delicate, web-like middle layer of meninges |
ascending tracts | nerve tracts in the spinal cord that carry information to the brain |
autonomic nervous system | 9visceral nervous system): portion of nervous system that regulates the activities of the internal organs (viscera) |
axon | nerve fiber; conducts an nerve impulse away from the neuron cell body |
central nervous system | brain and spinal cord |
cerebrospinal fluid | fluid in the ventricles of the brain, subarachnoid space of the meninges, and the central canal of the spinal cord |
dendrite | process of a neuron that receives input from other neurons |
descending tracts | nerve tracts in the spinal cord that carry information from the brain tothe muscles and glands |
dura mater | tough outer layer of meninges |
efferent neurons | motor neurons |
ganglia | a mass of neuron cell bodies, usually outside the CNS |
Gyri | ridges or convolutions on the surface of the cerebrum separated by shallow grooves called a sulcus or deep groove called a fissure |
meninges | membranes that cover the brain and spinal cord to muscles or glands |
motor neuron | efferent neurons carry impulse out of brain or spinal cord to muscles or glands |
myelin | fatty material that forms a sheath like covering around some axons |
neuron | nerve cell |
neurotransmitter | chemical that an axon end secretes on an effector (muscle or gland) or another neuron |
nervous system homeostasis | through sensation of changes in the internal and external environment, and the responses to those changes, the nervous system coordinates all other body systems to maintain homeostasis |
nodes of ranvier | narrow gaps in the schwann cells (myelin sheath)-that allow the impulse is conducted from node to node (saltatory conduction) and thus is sped up |
parasympathetic nervous system | portionof the autonomic nervous system that arises from the brain and sacral region of the spinal cord; most active under normal, restful conditions and couterbalances sympathetic nervous system |
peripheral nervous system | portion of the nervous system outside the central nervous system |
pia mater | inner layer of meninges that encloses the brain and spinal cord |
receptors | cell surface structures that detect changes in the environment and transmit a signal to the inside of the neuron |
resting potential | the difference in electrical charge between the inside and outside of an undisturbed nerve cell membrane |
sensory neuron | neuron that transmits an impulse from a receptor to the central nervous system |
spinal cord | portion of the central nervous system extending from the brain stem through the vertebral cord |
subarachnoid space | space within the meninges between the arachnoid mater and the pia mater |
sulcus | shallow groove on the surface of the brain |
sympathetic nervous system | portion of the autonomic nervous system that arises from the thoracic and lumbar regions of the spinal cord; prepares the body for energy-expending, stressful, or emergency situations |
synapse | connection between the axon of a neuron and the dendrite of another neuron |
contains typical organelles usually found in cells | cell body |
highly branched extension of cell body, main receptive surface of a neuron, conducts electrical signals toward the cell body | dendrites |
slender, cylindrical process of cell body that conducts nerve impulses away from the cell body | axon |
3 types of neurons | sensory neurons, interneurons, motor neurons |
afferent neurons that typically have a long dendrite and short axon, and carry messages from sensory receptors to the central nervous system | sensory neurons |
only found in the central nervous system where they connect neuron to neuron | interneurons |
efferent neurons that have a long axon and short dendrites and transmit messages from the central nervous system to the muscles (or to glands) | motor neurons |
myelinated nerves | white matter |
unmyelinated nerves | grey matter |
functions to increases the speed of conduction through neuron | myelin sheath |
when the nerve impulse jumps across the nodes of ranvier | saltatory conduction |
when the nerve impulse must travel the entire length of the axon | continuous conduction |
after passage of the action potential, there is a brief period, during which the membrane cannot be stimulated | refractory period |
the transmitting neuron | presynaptic neuron |
the recieving neuron | postsynaptic neuron |
the tiny space between the neurons | synaptic cleft |
these synapses occur rimarily between sooth muscle cells where quick, uniform innervation is essential | electrical synapses |
the simplest of nerve pathways, mediates a reflex action, and neurons do not pass directly into the brain, but synapse in the spinal cord | reflex arc |
medications that disrupt the sensory or motor pathway | ASA, anesthetics, morphine(opioids) |
most high level brain functions take place here | cerebrum |
five lobes of cerebrum | frontal, parietal, temporal, occipital, insula |
this lobe plays a part in impulse control, judgment, language production, working memory, motor function, sexual behavior, socialization, spontaneity, assist in planning, coordinating, controllin, and executing behavior | frontal lobe |
this lobes important roles are, integrating sensory information from various parts of the body, knowledge of numbers and their relations, manipulation of objects, portions of this lobe are invovled in spatial processing | parietal lobe |
this lobe is responsible for, sound processing, center for hearing, taste and smell, receives and inerprets sounds as words (auditory receptive aphasia) | temporal lobe |
this lobe is the functional visual areas | occipital lobe |
coodinates body movements, maintains posture and balance by controlling muscle tone and sensing the position of the limbs, all motor activity, from hitting a baseball to fingering a violin depends on this lobe | cerebellum |
the main relay station for incoming sensory signals to the cerebral cortex and for outgoing motor signal, all sensory input to the brain, except that of the sense of smell, connects to individual nuclei of this | thalamus |
controls many of the body's vital drives and activites, controls the function of internal body oragans by means of the autonomic nervous system, interacts closely with the pituitary gland, helps coordinate activities fo the brain stem | hypothalamus |
the three main structures lying between and below the two cerebral hemispheres | midbrain, pons, medulla oblongata |
the most primitive part of the brain and is responsible for sustaining the basic functions of life, such as breathing and blood pressure | brain stem |
the top most structure of the brain stem, contains major relay stations for neurons transmitting signals to the cerebral cortex, as well as many relex centers, relay and reflex centers for visual and auditory functions are located in the top portion | midbrain |
consists of large bundles of nerve fibers that connect the two halves of the cerebellum, connects each side of the cerebellum with the opposite-side cerebral hemisphere, serves mainly as a relay station linking the cerebral cortex and the medulla oblongat | pons |
long, stalk like lowermost portion of the brain stem | medulla oblongata |
three meninges that cover the spinal cord | dura mater, arachnoid membrane, and pia mater |
outermost layer, composed of tough, white fibrous connective tissue, contains many blood vessels and nerves | dura mater |
thin web-like membrane that lacks blood vessels, located between the dura mater and pia mater | arachnoid membrane |
thin delicat innermost layer attached to the organ surface, contains nerves and blood vessels | pia mater |
clear watery fluid that is secreted by choroid plexuses in the walls of the ventricles | cerebrospinal fluid |
interconnected cavities within the cerbral hemisphers and brain stem | ventricles |
two main components of peripheral nervous system | sensory pathways that provide input from the body into the cns, and motor pathways that carry signals to muscles and glands |
the peripheral nervous system can be subdivided into | somatic nervous system, and autonomic nervous system |
oversees conscious activity | somatic nervous system |
oversees unconscious activity, controls muscles in the heart, the muscle in internal organs such as the intestine, bladder, and uterus | autonomic nervous system |
two subsystems of autonomic nervous system | sympathetic nervous system, and parasympathetic nervous system |
fight or flight response | sympathetic nervous system |
relaxation | parasympathetic nervous system |