Neuromuscular Flashcards
What is the neurodevelopmental origin of the cerebral hemispheres?
Telencephalon
What fissure separates the temporal from frontal and parietal lobes?
Lateral central fissue
What is another name for the lateral central fissure
Fissure of Sylvius
What fissure separates the two cerebral hemispheres?
Longitudinal central fissure
What separates the frontal lobe from the parietal lobe?
Central sulcus
What are the 3 main anatomic features of the frontal lobe?
- Precentral gyrus
- Prefrontal cortex
- Broca’s area
What is the function of the precentral gyrus?
Primary motor cortex (voluntary muscle activation)
What is the function of the prefrontal cortex?
Controls emotions and judgements
What is the function of Broca’s Area?
Controls motor aspects of speech
What are the 2 main anatomic features of the Parietal Lobe?
- Postcentral gyrus
- Reception of fibers from touch, proprioceptive, pain, and temperature from contralateral side of body
What is the function of the postcentral gyrus?
Primary sensory cortex
What are the 3 main anatomic features of the temporal lobe?
- Primary auditory cortex
- Associative auditory cortex
- Wernicke’s area
What is the function of the primary auditory cortex?
Receives/ processes auditory stimuli
What is the function of the associative auditory cortex?
Processes auditory stimuli
What is the function of Wernicke’s area?
Language comprehension
What are the 2 main anatomic features of the occipital lobe?
- Primary visual cortex
- Visual association acortex
What is the function of the primary visual cortex?
Receives/ processes visual stimuli
What is the function of the visual association cortex?
Processes visual stimuli
Where is the insula located?
Deep within lateral sulcus
What is the function of the insula?
Visceral function
What anatomical features make up the limbic system?
- Limbic lobe
- Hippocampal formation
- Amygdaloid nucelus
- Hypothalamus
- Anterior nucleus of thalamus
What are the 3 anatomical features of the limbic lobe?
- Cingulate
- Para-hippocampal gyri
- Subcallosal gyri
What is the function of the limbic lobe?
- Instincts, emotions
- Feeding
- Aggression
- Emotions
- Endocrine aspects of sexual response
What is the function of the transverse/ commisural fibers?
Interconnect two hemispheres.
What are the 3 transverse/ commisural fibers?
- Corpus callosum
- Anterior commissure
- Hippocampal commissure
What is the function fo the projection fibers of the white matter?
- Connect cerebral hemispheres with other portions of the brain and spinal cord
What is the function of the association fibers of the white matter?
Connects different portions of the cerebral hemispheres so cortex can function cohesively
What four structures are the basal ganglia found in?
- Straitum
- Globus pallidus
- subthalamic nucleus
- Substantia nigra
What is the lenticular nucleus?
Putamen and globus pallidus
What is the function of the basal ganglia?
- Forms an associated motor system (extra-pyramidal system) with other nuclei in subthalamus and midbrain
What are the circuits of the basal ganglia?
- Oculomotor circuit (caudate loop)
- Motor loop (putamen loop)
- Limbic circuit
What is the origin and projection of the oculomotor circuit? What is its function?
- Originates in frontal and supplementary motor eye fields
- Projects to caudate
- Functions in saccadic eye movements
What is the origin and projection of the motor loop? What is its function?
- Origin in precentral motor and postcentral somatosensory areas
- Projects to and excites putamen
- Inhibits globus pallidus, which bossts activity in ventral lateral nucelus and supplemental motor area
- Scales amplitude and velocity of movements
- Reinforces selected patterns
- Suppresses conflicting patterns
- Prepares for movement
What is the origin and projection of the limbic circuit? What is its function?
- Origin in prefrontal and limbic areas of cortex
- Projects to basal ganglia and prefrontal cortex
- Organizes behaviors for procedural learning
What 4 anatomic structures make up the diencephalon?
- Thalamus
- Subthalamus
- Hypothalamus
- Epithalamus
What are the 3 types of nuclei found in the thalamus?
- Sensory nuclei
- Motor nuclei
- Other nuclei
What is the function of the sensory nuclei of the thalamus?
- Integrate and relay sensory information from body, face, retina, cochlea, and taste receptors to cerebral cortex and subcortical regions
What sensation is not processed at the sensory nuclei of the thalamus?
Smell
What is the function of the motor nuclei of the thalamus?
Relay information from cerebellum and globus pallidus to precentral motor cortex
What is the function of the other nuclei of the thalamus?
- Visceral and somatic function
What is the function of the subthalamus?
- Controls several functional pathways for sensory, motor, and reticular function
What are the 2 functions of the hypothalamus?
- Integrates and controls functions of the autonomic nervous system and neuroendocrine system
- Maintains body homeostasis
What are the 2 portions of the epithalamus?
- Habenular nuclei
- Pineal gland
What is the function of the habenular nuclei?
- Integrate olfactory., visceral and somatic afferent pathways
What is the function of the pineal gland?
- Secretes hormones that influence the pituitary gland, and several other organs
- Influences circadian rhythm
What are the 3 anatomic structures of the brainstem?
- Midbrain
- Pons
- Cerebellum
What structures does the midbrain connect?
Pons to cerebrum
What is the neurodevelopmental structure of the midbrain?
Mesencephalon
What connects the midbrain to the cerebellum?
Superior peduncle
The cerebral peduncles are located within the midbrain; what are their 2 portions?
- Anterior/ basis (crus cerebri, substantia nigra)
- Posterior (tegmentum)
What is contained within the tegmentum?
All ascending tracts, and some descending tracts.
What does the red nucleus (found in the midbrain) receive fibers from?
Cerebellum
What tract originates at the red nucleus?
Rubrospinal tract
What is the important function of the rubrospinal tract?
Coordination
What cranial nerve nuclei are located in the tegmentum of the midbrain?
Oculomotor, and trochlear.
What does the substantia nigra connect?
Basal ganglia and cortex
What is the function of the substantia nigra?
Large motor nucleus, important for motor control and muscle tone.
What is the function of the superior colliculus (found in the midbrain)?
Relay station for vision and visual reflexes.
What is the function of the inferior colliculus (found in the midbrain)?
Relay station for hearing and auditory reflexes.
What is contained in the periaqueductal grey (located int he midbrain)?
Endorphin producing cells for reduction of pain and descending autonomic tracts.
What does the pons connect?
Medulla oblongata to the midbrain
What passes through the pons?
Ascending and descending tracts
What part of the pons serves as a bridge to the cerebellum?
Anterior basal part (middle cerebellar peduncle)
What is the function of midline raphe nuclei (found within the pons)?
Modulate pain and control arousal.
What cranial nerve nuclei are found within the tegmentum of the pons?
- Abducens
- Trigeminal
- Facial
- Vestibulocochlear
What does the medulla oblongata connect?
Spinal cord and pons.
Relay nuclei for which tracts are located in the medulla oblangata? What structure do they form?
- Dorsal columns (gracillis, cuneatus)
- Medial lemniscus
What 2 structures is connected by the inferior cerebellar peduncle in the medulla oblongata?
- Dorsal spinocerebellar tract
- Cerebellum
What tracts cross in the medulla oblongata? What structure does this form?
- Corticospinal tracts
- Medullary pyramids
What does the medial longitudinal fasciculus arise from in the medulla oblongata?
- Vestibular nuclei
Where does the medial longitudinal fasciculus extend to?
Throughout brainstem and upper spinal cord
What is the function of the medial longitudinal fasciculus?
- Control of head movements
- Gaze stabilization
- Vestibular-ocular reflex
What nucleus in the medulla oblongata connects the cerebellum to the brainstem?
- Olivary nucleus complex
What is the function of the olivary nucleus complex?
- Voluntary movement control
What important cranial nerve nuclei are contained within the medulla oblongata?
- Hypoglossal
- Dorsal nucleus of vagus nerve
- Dorsal nucleus of vestibulocochlear nerve
What important centers for vital function are located in the medulla oblongata?
- Cardiac
- Respiratory
- Vasomotor
What bony landmark of the skull contains the cerebellum?
Posterior fossa
What joins the cerebellum to the brainstem?
3 cerebellar peduncles
- Superior
- Middle
- Inferior
What is found in the midline of the cerebellum?
The vermis
Is the cortex found on the outer portion or inner portion of the cerebellar?
Outer
What is found in the inner portion of the cerebellum?
White matter
How many paired nuclei are found within the cerebellum?
4
What system does the archicerebllum connect with?
Vestibular
What is the archicerebellum AKA?
Flocculonodular lobe
What is the function of the archicerebellum?
- Regulates muscle tone
- Coordinates vestibulo-ocular reflex
What system does the paleocerebellum connect with?
Proprioceptive
What is the paleocerebellum AKA?
- Rostral cerebellum, anterior lobe
- Rostral cerebellum
- Spinocerebellum
What is the function of the paleocerebellum?
- Modifies muscle tone
- Modifies synergistic action of mostures
- Postural control
- Voluntary movement control
What tracts does the neocerebellum receive input from?
- Corticopontocerebellar
- Olivocerebellar
What is the neocerebellum AKA?
- Cerebellar hemisphere
- Posterior lobe
- Pontocerebellum
What is the function of the neocerebellum?
- Smooth coordination of voluntary movements
- Accurate force, direction, and extent of movement
- Motor learning
- Sequencing of movements
- Visually triggered movements
- Cognitive function
- Mental imagery
What is the distal end of the spinal cord named?
Conus medullaris
What neurons are contained within the anterior horn of the gray matter of the spinal cord?
- Alpha motor neurons (to skeletal muscle)
- Gamma motor neurons (to muscle spindles)
What neurons are contained in the posterior horn of the gray matter of the spinal cord?
- Afferent neurons
Where are the cell bodies of the afferent neurons of the spinal cord located?
Within the dorsal root ganglia
Where are the 2 enlargements of the spinal cord? What is their function?
- Cervical and lumbosacral
- Provide innervation to upper and lower extremities
Where is the lateral horn of the gray matter of the spinal cord found?
In the thoracic and upper lumbar spinal cord.
What types of fibers are contained within the lateral horn?
Preganglionic
What are the 3 general organizations of white matter within the spinal cord?
- Anterior
- Lateral column/ funiculi
- Posterior (dorsal) column/ funiculi
What are the 4 ascending tracts of white matter found within the spinal cord?
- Dorsal columns/ medial leminiscal system
- Spinothalamic
- Spinocerebellar
- Spinoreticular
What are the 5 descending tracts of the white matter of the spinal cord?
- Corticospinal
- Vestibulospinal
- Rubrospinal
- Reticulospinal
- Tectospinal
What sensations are transmitted along the dorsal columns/ medial lemniscal system?
- Proprioception
- Virabtion
- Tactile discrimination
What are the 2 divisions of the dorsal columns?
- Fasciculus gracilis
- Fasciculus cuneatus
Does the fasciculus gracilis contain the upper extremity or lower extremity tracts?
Lower extremity
Does the fasciculus cuneatus contain the upper extremity or lower extremity tracts?
Upper extremity
How are the fasciculus gracilis and cuneatus arranged mediolaterally?
Gracilis is medial, cuneatus is lateral
To what higher structure do the dorsal columns ascend?
Medulla
What happens to the fibers of the dorsal columns in the medulla?
Cross to form medial lemniscus
What is the crossing of the fibers of the dorsal columns termed?
The lemniscal descussation
Where does the media lemniscus ascend to from the lemniscal decussation?
To thalamus, and then to somatosensory cortex
What sensations are conveyed along the spinothalamic tracts? What are the 2 associated tracts?
- Pain and temperature (lateral spinal thalamic tract)
- Crude touch (anterior spinothalamic tract)
How do the spinothalamic tracts ascend the spinal cord?
- Ascend one or two segments ipsilaterally in Lissauer’s Tract
- Synapse
- Cross to opposite side and ascend in ventrolateral spinothalamic system
What sensations are conveyed along the spinocerebellar tracts?
- Proprioception for control of voluntary movements
What sensory receptors provide information for spinocerebellar tracts?
- Muscle spindles
- Golgi tendon organs
- Touch and pressure receptors
What is the spinocerebellar tracts path up the spinal cord to higher centers?
- Dorsal spinocerebellar tract ascends to ipsilateral inferior cerebellar peduncle
- Ventrospinocerebellar tract ascends to contralateral and ipsilateral superior cerebellar peduncle
What sensations are conveyed along the spinoreticular tracts?
- Deep and chronic pain
What is the path up the spinal cord of the spinoreticular system?
Synapses on reticular formation of brainstem along diffuse, polysynaptic pathways
What is the function of the corticospinal tract?
- Vountary motor control
What is the path of the corticospinal tracts from higher centers down the spinal cord?
- Begins in primary motor cortex
- Descends to brainstem
- Crosses in pyramidal decussation in medulla
- Crossed fibers descend to ventral gray matter in lateral corticospinal tract
- 10% of fibers that do cross descend anterior corticospinal tract to cervical and upper thoracic segments
What is the function of the vestibulospinal tract?
- Controls muscle tone
- Antigravity muscles and postural reflexes
What is the path from higher centers down the spinal cord of the vestibulospinal tract?
- Begin in vestibular nucleus
- Descend spinal cord in lateral (crossed) and medial (uncrossed) vestibular tracts
Which vestibulospinal tracts are crossed?
Lateral
Which corticospinal tracts are uncrossed?
Anterior
What is the function of the rubrospinal tracts?
Assist in motor function
What is the path of the rubrospinal tracts from higher centers down the spinal cord?
- Begin in contralateral red nucleus
- Descend in lateral white columns to gray matter in spinal cord
What is the function of the reticulospinal system?
- Modifies transmission of sensation, especially pain
- Influences gamma motor neurons and spinal reflexes
What is the path of the reticulospinal system from higher centers down the spinal cord?
- Begins in reticular formation of brainstem
- Descends crossed and uncrossed in ventral and lateral columns
- Terminates on dorsal gray and ventral gray
What is the function of the reticulospinal tracts that terminate on the dorsal gray?
Modify sensation, especially pain
What is the function of the reticulospinal tract that terminates on the ventral gray?
Influences gamma motor neurons and spinal reflexes
What is the function of the tectospinal tract?
Assists in head turning responses to visual stimuli
What is the path of the tectospinal tract from higher centers down the spinal cord?
- Begins in superior colliculus
- Descends to ventral gray
What is the function of the autonomic nervous system?
- Innvervation of involuntary structures
Does the autonomic nervous system consist of afferent or efferent fibers? Preganglionic or postganglionic neurons?
- Both
- Both
Where are the nerve bodies of the sympathetic nervous system located?
T1-L2
What are the functions of the sympathetic nervous system?
- Increases heart rate
- Increases blood pressure
- Constricts peripheral blood
- Redistributes blood
- Inhibits peristalsis
Where are the nervebodies of the parasympathetic nervous system located?
- CN III
- CN VII
- CN IX
- CN X
- Pelvic nerves
What is the function of the parasympathetic nervous system?
- Conserves and restores hemeostasis
- Slows heart rate
- Reduces blood pressure
- Increases peristalsis and glandular activity
What are the 5 autonomic nerve plexuses?
- Cardiac
- Pulmonary
- Celiac
- Hypogastric
- Pelvic
What is the origin of the descending autonomic system? (for modulation)
- Begins in hypothatalmus and lower brainstem (cardiac, respiratory, vasomotor)
- Projects to preganglionic ANS in thoracolumbar and craniosacral region
What cranial nerves modulate the autonomic nervous system afferently?
- CN IX
- CN X
What cranial nerves modulate the autonomic nervous system efferently?
- CN III
- CN VII
- CN IX
- CN X
