Flashcards
Motor Systems
Cards in this deck (99)
- 1Where is the primary motor cortex found?In front of the central sulcus
- 2What is the function of the primary motor cortex?Execute or effect muscle control
- 3Where is the primary sensory cortex found?Behind the central sulcus
- 4What is the function of the primary sensory cortex?Receives sensation from the skin, muscles, and viscera
- 5Which cortex is located on the occipital lobe?Primary visual cortex
- 6What is the function of the primary visual cortex?Receive visual information from the retina
- 7Which cortex is located on the superior surface of the temporal lobe?Primary auditory cortex
- 8What is the function of the primary auditory cortex?To receive auditory information
- 9The motor system is a 2 neuron relay. What are the 2 types of neurons that make up this relay?Upper motor neurons
Lower motor neurons - 10Where are upper motor neurons found?In the primary motor cortex (M1), premotor area, or supplementary motor area
- 11Where are lower motor neurons found?Either in the cranial nerve nuclei or in the spinal cord
- 12What do the lower motor neurons do?Control the contraction of muscles
- 13What do the upper motor neurons project? Describe the route of these projectionsUpper motor neurons project axons down through the internal capsule, through the midbrain (pons and medulla)
As they leave the medulla, they decussate (cross midline), and then make a synaptic connection with lower motor neurons - 14What do the lower motor neurons project to?Skeletal muscle
- 15Upper motor neurons innervate lower motor neurons in which 2 regions?In the ventral horn of the spinal cord
In the cranial nerve motor nuclei - 16What do the lower motor neurons in the cranial nerve motor nuclei project to?Muscles of the face
Neck
Tongue
Larynx/pharynx - 17What are the 2 main functions of the motor neurons in the primary motor cortex?Control muscular force generated
Higher level control - control of limb trajectories and task specific muscle activation (e.g. precision vs power grip) - 18What do lower motor neurons in the spinal cord do?Regulate trunk axial muscles and appendicular (limb) muscles
- 19What do lower motor neurons in the cranial nerve motor nuclei do?Regulate the muscles of the head and neck
- 20What does the primary motor cortex receive a lot of its input from?Sensory association areas
- 21What are sensory association areas?Association area around the borders of a primary receiving area, where sensory stimuli are interpreted
- 22Which 2 areas of the cerebral cortex relay the information they receive to the sensory association cortex?Primary sensory cortex (S1)
Primary visual cortex - 23What happens in the sensory association cortex?The information received is integrated/computed which allows a perception of the outside world to be generated
- 24Where is the computed sensory information from the sensory association cortex sent? What does this allow?To the primary motor cortex (M1)
Which allows the M1 to plan and execute movement - 25As well as receiving information from the sensory association cortex, where else does the primary motor cortex receive information from?Direct stream of information sent from the primary sensory cortex to the primary motor cortex
- 26What do accessory motor areas have an important role in?Movement planning
- 27Name the 2 accessory motor areasPremotor area
Supplementary motor area - 28Where are the 2 accessory motor areas found?Just in front of the primary motor cortex
- 29As well as relaying information to the primary motor cortex, where else does the sensory association area relay information to?Premotor area
- 30What does the premotor area do with the information it receives from the sensory association area?Computes the information and either sends it to the primary motor cortex or directly to lower motor neurons
- 31What does the premotor area also contain? What does this mean?Upper motor neurons which project down the spinal cord
Means it can relay information directly to lower motor neurons - 32How is the supplementary motor area different from the premotor area?The supplementary motor area does not really receive any sensory information
- 33What does the supplementary motor area (SMA) have a role in?Memorised movement and initiation of these movements
- 34Where does the supplementary motor area (SMA) send information?Either to the primary motor cortex (which then sends it down the spinal cord) or to the lower motor neurons directly through the spinal cord (as it has its own upper motor neurons)
- 35What is the premotor area involved in?Movement planning - using visuospatial information to guide movement
- 36In what species of animals has the pyramidal motor pathway only really developed?Primates (particularly well-developed in humans)
- 37Which 2 fibre tracts is the pyramidal motor pathway comprised of?Corticobulbar tract
Corticospinal tract - 38Where does the corticospinal tract start and end?Starts in the motor cortex
Ends in the spinal cord - 39Where does the corticobulbar tract start and end?Starts in the cortex
Ends in the cranial nerve motor nuclei - 40What does the pyramidal motor pathway arise from?From upper motor neurons of the primary motor cortex, premotor area (PMA), and supplementary motor area (SMA)
- 41What does the pyramidal motor pathway mediate?Conscious control of motor activity
- 42Describe the general pathway of neurons from the primary motor cortexUpper motor neurons project their axons down through the internal capsule
Make a synaptic connection with lower motor neurons either in the cranial nerve motor nuclei (found in the midbrain, pons and medulla) or the axons pass through the midbrain, pons and medulla to make a connection with lower motor neurons in the spinal cord - 43Where do the corticobulbar fibres decussate?At the level of the individual cranial nerve motor nuclei
- 44What happens at the level of the individual cranial nerve motor nuclei?The corticobulbar fibres decussate
- 45Name the 2 cranial nerve motor nuclei in the midbrainOculomotor
Trochlear - 46What do the oculomotor and trochlear cranial nerve motor nuclei do?Contain motor neurons that control the movement of the eye - innervate the extrinsic muscles of the eye
- 47How are the lower motor neurons in the oculomotor and trochlear nerve motor nuclei innervated?Bilaterally
- 48What does it mean to be innervated bilaterally by the cortex?Innervated both contralaterally from the motor cortex on the opposite side of the cerebral hemispheres, and from upper motor neurons on the same side of the brain
- 49Bilateral innervation of the oculomotor and trochlear nerve motor nuclei is likely to be an evolutionary adaptation. Why is this useful?If one side of the brain is damaged, you can still retain movement of the extrinsic eye muscles and the ability to see properly
- 50Name the cranial nerve motor nuclei located in the ponsTrigeminal motor nucleus
Abducens motor nucleus
Facial motor nucleus - 51What type of innervation does the trigeminal nerve motor nucleus receive?Contralateral
- 52What do the neurons contained within the trigeminal motor nucleus innervate?Muscles of mastication and muscles used for speech
- 53What type of innervation does the abducens motor nucleus receive?Bilateral innervation
- 54What do the lower motor neurons in the abducens motor nucleus innervate?Extrinsic eye muscles
- 55What type of innervation does the facial motor nucleus receive?Mainly contralateral but some bilateral (muscles above eye, forehead) innervation
- 56What do the lower motor neurons of the facial motor nuclei do?Control the muscles of facial expression
- 57Name the 2 cranial nerve motor nuclei located in the medullaNucleus ambiguus
Hypoglossal nerve motor nucleus - 58What does the nucleus ambiguus contain?Lower motor neurons that innervate the muscles of the larynx and pharynx and some muscles of the neck and shoulders
- 59What do the lower motor neurons of the hypoglossal nerve motor nucleus do?Innervate the tongue and control its movement
- 60What type of innervation do the motor nuclei in the medulla receive?Contralateral innervation
- 61What do the axons of motor neurons in the cortico-spinal tract do?Axons project all they way through the midbrain, pons, and medulla without synapsing with lower motor neurons
Axons leave the medulla and decussate (90% of them) to become the lateral corticospinal tract - this innervates lower motor neurons which control the muscles of the limbs/trunk
Remaining 10% of axons pass down the ventral region of the spinal cord as the medial corticospinal tract - these then decussate at the level of the lower motor neurons - 62Why is it called the pyramidal motor pathway?Because the cross-section of the corticospinal fibres as they emerge from the medulla is pyramidal
- 63Which of the following two motor pathways is evolutionary ancient? Which of the following two motor pathways is evolutionary recent? Pyramidal motor pathway Extra-pyramidal motor pathwayPyramidal - evolutionary recent (primates)
Extra-pyramidal - evolutionary ancient (in all vertebrates) - 64Name the components of the extra-pyramidal motor pathways- Cerebellum
- Vestibular system
- Basal ganglia
- Thalamus
- Reticular formation nuclei
- Midbrain nuclei
- Cortex - 65What does the extra-pyramidal motor pathway mediate?Unconscious control of motor activity (posture, balance, reflexes)
Note// pyramidal and extra-pyramidal motor pathways do not work in isolation - work closely together to coordinate posture, reflexes and voluntary movement - 66What does the cerebellum do? How does it do this?Compares the movement outcome with the intention of that movement
Does this by receiving ascending sensory input and descending motor input from M1 - 67What do the basal ganglia do?Exchange information with the primary motor cortex and thalamus
Co-ordinate different motor subroutines/movement execution - 68What is the thalamus a relay between?Between the basal ganglia and cortex
- 69What reflexes does the midbrain tectum play a role in?Visual and auditory reflexes
- 70Name the 4 main extra-pyramidal motor pathwaysReticulospinal tract
Tectospinal tract
Vestibulospinal tract
Rubrospinal tract - 71Where does the reticulospinal tract begin and end?Begins at the reticular formation
Ends at the spinal cord - 72Which 3 structures continually exchange information to coordinate motor output/execution?Basal ganglia
Thalamus
Cortex - 73Where does the reticulospinal tract emanate from?Neurons within the pontine and medullar reticular nuclei (reticular nuclei within the pons and medulla)
- 74What is input to the reticular nuclei neurons predominantly from?From the cortex via the corticopontine tract and from the vestibular nucleus
- 75What is input to the vestibular nucleus from?Cerebellum and inner ear
- 76Describe the projection of reticulospinal tract axonsThey project to the lower motor neurons that innervate the trunk, head/neck, and proximal limb muscles
- 77What does the reticulospinal tract control?Muscle tone
Posture
Simple stereotyped movements - 78Where does the tectospinal tract begin and end?Begins at the midbrain tectum
Ends at the spinal cord - 79Where, specifically, in the midbrain tectum does the tectospinal tract emerge from?From neurons in the superior colliculus of the midbrain tectum
- 80What is the input to the superior colliculus of the midbrain tectum mainly from?Retina and visual cortex (visual information)
Or the inferior colliculus and auditory cortex (auditory information) - 81Fill in the gaps: The superior colliculus receives a steady stream of information that is both [?] and [?].Visual
Auditory - 82What do the axons of the tectospinal tract project to?Cervical spinal cord lower motor neurons that innervate the neck and upper back muscles
- 83What do the cervical spinal cord lower motor neurons innervate?Neck and upper back muscles
- 84What is the function of the tectospinal tract?Coordinate reflex head movement towards auditory or visual stimuli
- 85What does the vestibulospinal tract arise from?Neurons within the superior, lateral and medial vestibular nuclei
- 86Where does the input to the vestibular nuclei neurons come from?Inner ear and cerebellum
- 87What do the axons of the vestibulospinal tract project to?Cranial nerve motor nuclei containing lower motor neurons that innervate the extrinsic eye muscles (III, IV and VI)
- 88Fill in the gaps: The vestibulospinal tract axons project in the ascending [?] [?] [?] to cranial nerve motor nuclei.medial longitudinal fasciculus
- 89What is the medial longitudinal fasciculus?A myelinated composite fibre tract found in the brainstem
- 90What does the descending medial longitudinal fasciculus do?Carries vestibulospinal tract axons that innervate lower motor neurons that control upper back and neck muscles
- 91Other than innervate the extrinsic eye muscles and upper back and neck muscles, what does the vestibulospinal tract do?It descends down the spinal cord to lower more neurons innervating proximal leg muscles
- 92Fill in the gaps: The VST plays a role in coordinating [?] and keeping the [?] balanced and [?] horizontal when the body is moving.The VST plays a role in coordinating balance and keeping the head balanced and eyes horizontal when the body is moving.
- 93Where does the rubrospinal tract arise from?Neurons within the red nucleus of the midbrain tegmentum
- 94What does the red nucleus mainly receive direct input from?The motor cortex
- 95Where do axons arising from the red nucleus decussate?In the pons
- 96What do the axons from the red nucleus do once they decussate in the pons?Innervate lower motor neurons at all levels of the spinal cord
- 97What does the rubrospinal tract appear to have a similar function to?The lateral corticospinal tract in (non-primate) mammals
- 98What does the rubrospinal tract modulate?Lateral corticospinal tract induced motor activity in humans
- 99Pyramidal and extra-pyramidal spinal motor pathway locations
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- Undergraduate Other Flashcards on Motor Systems, created by Riya X on 10/08/2021.
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