Neural Control of Voluntary Movement Flashcards
Every muscle fiber is innervated by ______
somatic motor neuron
Five levels of control of the Central Nervous System
- cerebral cortex
- basal ganglia
- cerebellum
- brain stem
- spinal cord
Cerebral cortex
- highest level of control
- provides for the creation of voluntary movement as aggregated muscle action, but not as specific muscle activity
What does cerebral cortex interprets?
It interprets sensory stimuli from a body to a degree of needed responses
Basal Ganglia
-the next lower level from cerebral cortex
What does basal ganglia control?
- maintenance of postures & equilibrium
- learned movements such as driving a car
- sensory integration for balance & rhythmic activities
Cerebellum
- a major integrator of sensory impulses
- provides feedback relative to motion
What does cerebellum control?
timing and intensity of muscle activity to assist in the refinement of movements
Brain stem
-integrates all CNS activity through excitation and inhibition of desired neuromuscular functions
What does brain stem functions in?
Functions in arousal or maintaining a wakeful state
Spinal cord
- common pathway between CNS and PNS
- has the most specific control
Spinal cord integrates _____ and ______
- various simple & complex spinal reflexes
- cortical and basal ganglia activity with various classifications of spinal reflexes
Peripheral Nervous System (PNS) is divided into ___ and ____.
sensory & motor division
What is the PNS sensory division?
Sensory or afferent nerves bring impulses from receptors in skin, joints, muscles, & other peripheral aspects of body to CNS
What is the PNS motor division?
Motor or efferent nerves carry impulses to outlying regions of body from the CNS
Efferent nerves are subdivided into ___ and ____.
voluntary (somatic nerves) & involuntary (visceral nerves)
What are somatic nerves?
- voluntary
- under concious control & carry impulses to skeletal muscles
What are visceral nerves?
- involuntary
- referred to as the autonomic nervous system (ANS)
- carry impulses to the heart, smooth muscles, and glands
PNS - 2 groups of nerves of primary importance
- cranial nerves
- spinal nerves
What are cranial nerves?
12 pair originating from undersurface of brain & exiting from the cranial cavity through skull openings
How are cranial nerves numbered?
numbered or the order in which they emerge from anterior to posterior
How are cranial nerves named?
named in relation to their function or distribution
Olfactory functions
- smell
- identifying familiar odors
Optic functions
- sight or vision
- visual acuity
oculomotor
- levator of eyelid
- upward, downward, & medial gaze, reaction to light
Trochlear
- superior oblique muscle of eyeball
- downward and lateral gaze
Trigerminal
- touch, pain
- muscles of mastication/chewing
Facial
taste, touch, pain, facial muscles
Vestibulocochlear (acoustic nerve)
- hearing, equilibrium/balance
- detecting presence of sounds, balance, & coordination
Glossopharyngeal
- touch, pain
- taste
- muscle of pharynx
- gag reflex, swallowing
Vagus
- touch, pain
- muscles of palate, pharynx, larynx
- gag reflex, swallowing, speech
Accessory
- sternocleidomastoid & trapezius muscle
- shoulder shrugging, head movement
hypoglossal
- muscles of tongue
- tongue movements
Spinal nerves
- 31 pairs originate from the spinal cord
- pass through openings between vertebrae on each side
From each of side of spinal column, there are _____
- 8 cervical nerves
- 12 thoracic nerves
- 5 lumbar nerves
- 5 sacral
- 1 coccygeal nerve
What forms the cervical plexus?
Cervical nerves 1 through 4
Cervical plexus is responsible for ___
generally responsible for sensation from upper part of shoulders to back of head and front of neck
What forms the brachial plexus?
Cervical nerves 5-8 & thoracic nerve 1
Cervical plexus supplies _____
Supplies motor innervation to several muscles of the neck
Brachial plexus supplies _____
Supplies motor & sensory function to the upper extremity and most of the scapula
What forms the lumbosacral plexus?
All lumbar, sacral, and coccygeal nerves
Lumbosacral plexus supplies _____
Supplies sensation & motor function to lower trunk, entire lower extremity & perineum
What is the function of spinal nerves?
Sensory function of spinal nerves is to provide feedback to CNS regarding skin sensation
Dermatome
defined area of skin supplied by a specific spinal nerve
Myotome
muscle or group of muscles supplied by specific spinal nerve
What are neurons?
Basic functional units of nervous system responsible for generating & transmitting impulses
What are dendrites?
one or more branching projections which transmit impulses to neuron and cell body
What are axon?
an elongated projection that transmits impulses away from neuron cell bodies
What are sensory neurons?
transmit impulses to spinal cord & brain from all part of body
What are motor neurons?
transmits impulses away from the brain & spinal cord to muscle & grandular tissue
What are interneurons?
are central or connecting neurons that conduct impulses from sensory neurons to motor neurons
