Chapter 8 - Nervous System Vocabulary Flashcards
Autonomic nervous system
A subdivision of the nervous system that operates without conscious control and regulate the function of the internal organs, glands, and smooth muscles; comprised of the sympathetic and parasympathetic nervous system
Nervous system
The system that controls virtually all activities of the body, both voluntary and involuntary
Somatic nervous system
The part of the nervous system that regulates activities over which there is voluntary control
Neurons
The basic nerve cells of the nervous system, containing a nucleus within a cell body and extending one or more processes; they exit in masses to form nervous tissue
Axons
Long, slender filaments projecting from a nerve cell that conducts impulses to adjacent cells
Dendrites
The parts of the neuron that receives impulses from the axon and contains vesicles for release of neurotransmitters
Neuroglia
One of two basic types of neural tissue, neuroglia support, protect, defend, and aid in the repair of injury of neural tissue, and regulate composition of nervous system interstitial fluid.
Unmyelinated axons
Neurons with no myelin sheath or white matter
Schwann cells
Nervous tissue that helps form the myelin sheath around certain neurons
Myelinated nerves
An axon surrounded by a membrane sheath produced by Schwann cells
Myelin sheath
A membrane formed by Schwann cells, which cover the axons of certain neurons
Node of Ranvier
Regions between individual Schwann cells in myelinated neurons, between which action potential jumps
White matter
Bundles of myelinated nerves
Synapse
The junction between nerve cells across which nervous stimuli are transmitted. Includes the synaptic cleft, presynaptic cell membrane with synaptic vesicles and axon terminal and postsynaptic cell membrane.
Postsynaptic terminal
The end of a nerve were electrical impulses are received from the synaptic cleft
Presynaptic terminal
The end of a nerve where neurotransmitters are released into the synaptic cleft
Synaptic cleft
The space between neurons where electrical impulses trigger the release of neurotransmitters, which in turn stimulate an electrical reaction in adjacent neurons
Synaptic vesicles
Vesicles that contain neurotransmitters
Neurotransmitters
Chemicals produced by neurons that stimulate electrical reactions in adjacent cells
Nerve
Nervous tissue that connects the nervous system with body parts or organs
Nerve fibers
Groups of nerve cells that are bundled together
Brain
The controlling organ of the body and center of consciousness;
functions include:
- perception
- control of reactions to the environment
- emotional responses
- judgement
Brainstem
The area of the brain between the spinal cord and cerebrum, surrounded by the cerebellum; controls functions that are necessary for life, such as Respirations
Central nervous system
The brain and the spinal cord
Cerebrum
The largest portion of the brain that controls higher thought processes, including:
- control of movement
- hearing
- balance
- speech
- visual perception
- emotions
- personality
Also called cerebral cortex
Substantia nigra
A layer of gray matter located in the mid-brain
Spinal reflex arcs
automatic reactions to stimuli mediated by Neuronal pathways within the spinal cord that occur without conscious thought
sulci
Grooves located between the gyri in the cerebrum
Flexor reflex
A withdrawal telex in the flexor muscles of the limbs that contract in response to an unpleasant stimulus
Ascending reticular activating system
Several structures located throughout the brain stem that are responsible for maintenance of consciousnesses
Longitudinal fissure
The crevasse that separates the right and left hemisphere of the cerebrum
Gyri
The numerous folds in the cerebrum, which greatly increase the surface area of the cortex
Frontal lobe
The portion of the brain that is important in voluntary motor actions and personality traits
lobes
Subdivisions within each hemisphere of the cerebrum; each lobe shares the name of the bone of the skull that overlies it
Cerebral cortex
The largest portion of the brain, it controls the higher thought processes; also called the cerebrum
Occipital lobe
The portion of the brain that is responsible for the processing of visual information
Temporal lobe
The portion of the brain that plays an important role in hearing and memory
Parietal lobe
The portion of the brain that is the site for reception and evaluation of most sensory information, except smell, hearing, and vision
Diencephalon
The part of the brain between the brainstem in the cerebrum that includes the thalamus and hypothalamus
Thalamus
The part of the diencephalon the processes most sensory input and influences mood and general body movements, especially those associated with fear or rage
Subthalamus
The part of the diencephalon that is involved in controlling motor functions
Epithalamus
Part of the diencephalon with functions related to emotions, circadian rhythms, and connecting the limbic system with other parts of the brain
Hypothalamus
The most inferior portion of the diencephalon; it is responsible for control of many body functions, including – pulse rate – digestion – sexual development – temperature regulation – emotion – hunger – Thirst – regulation of the sleep cycle
Pineal body
Part of the epithalamus in the diencephalon
Basal ganglia
(Basal nuclei) structures located deep within the cerebrum, diencephalon, and midbrain that okay an important role in coordination of motor movement and posture
Limbic system
Structures within the cerebrum and diencephalon that influence emotions, motivation, mood, and sensation of pain and pleasure
Pons
The portion of the brainstem that lies below the midbrain and contains nerve fibers that affect sleep and respirations
Medulla oblongata
The inferior portion of the midbrain, which serves as a conduction pathway for both ascending and descending nerve tracts
Cerebellum
The region of the brain essential in coordinating muscle movements of the body
Cerebellum peduncles
One of the three bands of nerve fibers through which the cerebellum communicates with other regions of the central nervous system
Stroke
Brain damage typically resulting from a disruption of the circulation to the brain, causing abnormal neurologic findings
Embolic stroke
Result of a blood clot that arises in the heart because of the cardiac rhythm disorder such as atrial fibrillation
Transient ischemic attack
An episode of a neurologic impairment that lasts less than 24 hours and represents a warning sign of an impending stroke
Meninges
A set of three tough membranes, Dura matter, arachnoid, and Pia matter, that encloses the entire brain and spinal cord
Meningitis
An inflammation of the meninges and CSF, usually caused by infection
Dura mater
The outermost of the three meninges that enclose the brain and spinal cord; it is the toughest membrane
Pia mater
The innermost of the three meninges that enclose the brain and spinal cord; it rests directly on the brain and spinal cord
Arachnoid
The middle membrane of the three meninges that enclose the brain and spinal cord
Cerebrospinal fluid
Fluid produced in the ventricles of the brain that flows in the subarachnoid space and bathes the meninges
Subarachnoid space
The space located between the pia mater and the arachnoid in which the CSF is contained
Subarachnoid hemorrhage
A hemorrhage into the brain tissues beneath the arachnoid membrane
Lumbar puncture
A needle insertion through the vertebral canal into the subarachnoid space to obtain a specimen of CSF
Spinal tap
Same as lumbar puncture
Choroid plexus
Specialized cells within hollow areas in the ventricles of the brain that produce CSF
Ventricles
Specialized fluid-filled areas in the brain
hydrocephalus
A birth defect result from a blockage in the ventricles that causes CSF to build up, Denning the cortex and causing severe brain damage
Obstruction to the flow of CSF results in increased pressure within the brain tissue, dilation of the ventricles, and compression of the brain
Spinal cord
An extension of the brain, composed of virtually all the nerves carrying messages between the brain and the rest of the body; it lies inside of and is protected by the spinal canal
Foramen magnum
A large opening at the base of the skull through which the spinal cord exits the brain
Cauda equina
Numerous individual nerve roots that extend from the spinal cord at the level of the second lumbar vertebra
Vertebral canal
The bony canal formed by vertebrae that houses and protects the spinal cord
Tracts
Pathways within the spinal cord that contains nerves
Sciatica
Pain and muscle weakness that travels from the back, into the buttocks, and along the leg into the foot as a result of irritation of the sciatic nerve or lumbar spinal nerve root
Ascending tracts
Fibers that carry sensory information from the periphery to the brain; also called Afferent tracts
Action potential
An electrochemical event associated with cell membrane depolarization where stimulation of a nearby cell could cause excitation of another cell
Descending tracts
Fibers that carry motor impulses from the brain to the fibers of the peripheral nervous system; also called efferent tracts
Anterior spinothalamic tracts
Ascending fiber tracts that carry information to the brain about light touch, pressure, and tickling and itching sensation.
Lateral spinothalamic tracts
Ascending tracts that carry information to the brain about pain and temperature
Spinocerebellar tracts
Ascending tracts that carry information regarding body posturing (proprioception) to the cerebellum
Proprioception
Information about the body’s position and of its parts in relation to itself, to one another, and to the pull of gravity
Corticospinal tracts
Descending tracts that coordinate movements, especially of the hands
Vestibulospinal tracts
Descending tracts involved in involuntary body movements
Reticulospinal tracts
Descending tracts that are involved in involuntary body movements
Peripheral nervous system
The portion of the nervous system that consists of 31 pairs of spinal nerves and 11 of the 12 pairs of cranial nerves; these nerves may be sensory, motor, or connecting nerves
Ganglia
Collections of nerve cell bodies located outside the central nervous system
Spinal nerves
Thirty one pairs of nerves each responsible for sending and receiving sensory and motor messages to and from the central nervous system from a portion of the body.
Rootlets
Small nerves
Ventral root
One of two roots of a spinal nerve that is formed from six to eight rootlets
Dorsal root
One of two roots of a spinal nerve that passes posteriorly into the spinal cord and contains the dorsal root ganglion
Dorsal root ganglion
A ganglion in the dorsal root of each spinal nerve
Intervertebral foramen
Openings between successive vertebrae through which nerves exit the vertebral column
Sensory nerves
Nerves that carry sensations of touch, taste, heat, cold, pain, and other modalities from the body to the central nervous system
Afferent nerve
Nerves that send information to the brain; also called sensory nerves
Dermatome
An area of skin that corresponds to the sensory distribution of a specific cranial or spinal nerve
Motor nerves
Nerves that carry commands from the brain to the muscle; also called efferent nerves
Efferent nerves
Nerves that carry commands from the brain to peripheral muscles; also called motor nerves
Neuromuscular junction
The receptor on the muscle for nerve impulses
Plexuses
Complex networks made up by the combination of the main portions of the spinal nerves
Peripheral nerves
Nerves that arise from the different plexuses to branch and supply motor functions to and convey sensory information from many areas of the body
Curare
An agent that blocks transmission of neural motor impulses at the neuromuscular junction
Neuromuscular blockers
A group of drugs derived from curare that are used in anesthesia to induce muscle relaxation
Brachial plexus
The plexus of the spinal nerves that consists of nerves C5 to T1 and innervate a the shoulder and upper extremities
Axillary nerve
One of the major nerves emanating from the brachial plexus;
it supplies the deltoid and teres minor muscles, enabling arm abduction and lateral rotation
Radial nerve
One of the major nerves in the upper extremity, it supplied muscles that
Extend the elbow (brachioradialis and triceps brachi)
Supinate the forearm (supinator)
Extend the wrist (extensor carpi muscles), fingers (extensor digitorun), and thumb
Musculocutaneous nerve
A nerve in the upper extremity that innervates muscles that flex the shoulder and elbow (coracobranchialis, biceps branchii, brachialis)
Median nerve
The nerve in the brachial plexus that innervates the pronator muscles of the forearm, as well as those that flex the
wrist (flexor carpi muscles and palmar is longus)
fingers (flexor digitorum muscles)
Thumb (flexor pollicis longus)
Ulnar nerve
The nerve in the arm that innervates the muscles that flex the
wrist (flexor carpi ulnaris)
fingers (flexor digitorum muscles)
and abduct and adduct the fingers and thumb
(interossei, adductor pollicis, and abductor pollicis)
Adulatory nerve - sensory distribution
Innervates a small patch of skin on the lateral border of the proximal arm.
Radial nerve - sensory innervation
Posterior arm and forearm
Lateral 2/3rds of the dorsum of the hand
Musculocutaneous - sensory innervation
Lateral surface of forearm
Ulnar nerve - sensory innervation
Medial 1/3rd of the hand
Little finger
Medial 1/2 of ring finger
Median nerve - sensory innervation
Lateral 2/3rds of palm of hand including lateral half of the ring finger
Lumbosacral plexus
A combination of the lumbar plexus and, sacral plexus and the coccygeal foot
Obturator nerve
A nerve emanating from the lumbosacral plexus that innervate the muscles that adduct the thigh (adductor muscles and gracilis) and rotate it laterally (obturator externus)
Femoral nerve
Branch of the lumbosacral plexus that innervates the muscles that flex the hip (psoas major and sartorius) and extend the knee (rectus femoris and the vastus muscles)
Tibial nerve
The nerve in the leg that innervates the muscles that
extend the hip and flex the knee (biceps femoris, semitendinosus, semimembranosus, and popliteus)
plantar flex the ankle (gastrocnemius, soleus, plantaris, and tibialis posterior)
flex the toes (flexor muscles)
Common peroneal nerve
A major nerve of the leg, providing sensation to the lateral leg and dorsum of the foot and motor activity to hip extensors, knee flexors, ankle Dorsiflexors, and toe extensors
Sciatic nerve
The longest peripheral nerve in the body, formed by the combination of the common peroneal nerve and the tibial nerve
Deep peroneal nerve
A component and branch of the common peroneal nerve that innervates of the muscles of the Dorsiflex the ankle and extend the toes
Superficial peroneal nerve
The nerve in the leg that innervates the muscles of foot Eversion
