TASK 5 Flashcards
REFLEXES
_reflexes – basic units of behaviour. A simple, and unlearned response to a particular stimulus
_motor plan (or motor program)
– complex set of commands to muscles that is established before the behaviour starts. A plan for action in the nervous system _motor behaviour can be analysed with videos, or EMG (electromyography, electrical activity of muscles)
MECHANISM THAT REGULATE AND CONTROL OUR MOVEMENTS
_closed-loop control mechanisms _open-loop control mechanisms
_closed-loop control mechanisms
– control mechanism that TRANSPORT information from what is being controlled to the device that controls it. MAXIMIZE ACCURACY (prevent or minimize error)
_open-loop control mechanisms
– a control mechanism that DOES NOT give FEEDBACK because has to respond as fast as possible. MAXIMIZE SPEED (to complete a task quickly and efficiently)
_ballistic movements
– a rapid muscular movement that is generally preprogramed
_skeletal system
– determines which movements are possible _muscles control actions of skeletal system IN THERE THERE ARE _smooth muscle _tendons _antagonist muscles _synergists _motor neuron
_smooth muscle
– a type of muscle fibre, as in the heart, that is controlled by the autonomic nervous system rather than by voluntary control . IN THE SKELETAL SYSTEM
_tendons
– strong tissue that connects muscle to bone . IN THE SKELETAL SYSTEM
_antagonist muscles
– a muscle that counteracts the effect of another muscle . IN THE SKELETAL SYSTEM
_synergists
– a muscle that acts together with another muscle . IN THE SKELETAL SYSTEM
_motor neuron
– a neuron in the brain or spinal cord that transmits motor messages to a muscle. IN THE SKELETAL SYSTEM
_spinal cord
– controls skeletal muscles in response to sensory information, also implements motor commands from the brain
_brain stem
– integrates motor commands from higher levels of the brain and transmits them to the spinal cord. Also, it relays sensory information about the body from the spinal cord to the forebrain
_non primary motor cortices
– provide an additional source of motor commands, acting indirectly via primary motor cortex
_ cerebellum and basal ganglia
– modulate activity of every control system below them. Some of their contributions are routed via the thalamus in a loop back to the cortex
_automatic movements and control
_stretch reflex – the contraction of a muscle in response to a stretch of that muscle _central pattern generator – neural circuitry that is responsible for generating rhythmic pattern of a behaviour such as walking (most locomotion is rhythmic)
_stretch reflex
– the contraction of a muscle in response to a stretch of that muscle, , it is monosynaptic, meaning that involves transmission of information from a sensory neuron to the appropriate motor neuron across a single synapse in the spinal cord- IT DOESN’T GO TO THE BRAIN
_central pattern generator
– neural circuitry that is responsible for generating rhythmic pattern of a behaviour such as walking (most locomotion is rhythmic)
_injuries OF SPINAL CORD
_flaccid paralysis _motor-neuron pathology
_flaccid paralysis
– it generally results just when considerable length of the spinal cord has been destroyed. It is a loss of reflexes below the level of transection of the spinal cord
_motor-neuron pathology
_amyotrophic lateral sclerosis (ALS) _polioviruses INJURY OF THE SPINAL CORD
_polioviruses
INJURY OF THE SPINAL CORD, MOTOR-NEURON PHATOLOGY – a class of viruses that destroy motor neurons of the spinal cord and brainstem
_amyotrophic lateral sclerosis (ALS)
INJURY OF THE SPINAL CORD, MOTOR-NEURON PHATOLOGY – A disease in which motor neurons and their target muscles waste away
_brain controls different aspects of movements by…
pyramidal extra-pyramidal systems SPINAL CORD
_pyramidal system
– consists of neuronal cell bodies within the cerebral cortex and their axons, which pass through the brainstem , forming the pyramidal tract to the spinal cord _many of the axons of the pyramidal tract originate from neurons in the _primary motor cortex (M1). It also has a non-primary motor cortex. SPINAL CORD
_primary motor cortex (M1)
– consists mainly in precentral gyrus. The cell bodies of many of these large neurons are found in layer V of the primary motor cortex. Motor representations in M1 change as a result of training (memory) SPINAL CORD, PYRAMIDAL SYSTEM
_non primary motor cortex
– anterior to M1, cortical regions that are also important for motor control, and they can contribute to behaviour directly, through communication with lower levels of the motor hierarchy in the brainstem and spinal cord system, as well as indirectly through M1. _supplementary motor area (SMA) _premotor cortex SPINAL CORD, PYRAMIDAL SYSTEM
_supplementary motor area
IT INCLUDES
SMA, preSMA and supplementary eye field
– a region of non-primary motor cortex that receives inputs from the basal ganglia and modulates the activity of the primary motor cortex. Activated when motor sequences are guided internally by stimuli SPINAL CORD, NON PRIMARY MOTOR CORTEX, PYRAMIDAL SYSTEM
_premotor cortex
IT IS DORSAL OR VENTRAL
– a region of non-primary motor cortex just anterior to the primary motor cortex. Activated when motor sequences are guided externally by stimuli SPINAL CORD, NON PRIMARY MOTOR CORTEX, PYRAMIDAL SYSTEM
_extrapyramidal system
– a motor system that includes the basal ganglia and some closely related brainstem structures (cerebellum overall) _messages from basal ganglia and cerebellum are transmitted via _ticulospinal tract _rubrospinal tract
_corticospinal tact
IT IS A LATERAL PATHWAY
_messages from basal ganglia and cerebellum are transmitted via this (originates in the reticular formation of the brainstem) , it sends axons down the spinal cord to synapse on spinal interneurons – controls hands and fingers movements so DIPENDENT of trunk movements- they form the pyramidal tract
_rubrospinal tract
IT IS A LATERAL PATHWAY _messages from basal ganglia and cerebellum are transmitted via this (originates from the midbrain’s red nucleus) , it sends axons down the spinal cord to synapse on spinal interneurons _they do not control hands and fingers movements so INDEPENDENT of trunk movement– they form the extrapyramidal tract
_basal ganglia
– lesions of the basal ganglia produce movement impairment – Parkinson’s disease and Huntington’s disease are caused by the generation of the basal ganglia. It lays a role in determining the amplitude and the direction of movement and the initiation of movement. The basal ganglia is especially important in the performance of movements influenced by memories, in contrast to those guided by sensory control
_cerebellum
– affects programs, coordination and learning of acts – guides movement by inhibiting neurons at the Purkinje cells that synapse with the deep cerebellar nuclei. Controls skilled movements, particularly fast and repeated so that become automatic
MIRROR NEURONS
A neuron that is activated when both -an individual makes a particular movement -when that individual sees another individual make the same movement They’re in frontal and parietal cortex May suggests a neural basis for empathy
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_withdrawal reflex
– the contraction of a muscle when a painful stimulus is encountered , it is NOT monosynaptic.
and it takes longer (an interneuron is involved as well, more muscles are involved and thus move. IT DOES NOT GO TO THE BRAIN)
_association cortex
it is part of the skeletal system. Composed by
_posterior parietal association cortex
_dorsolateral prefrontal association cortex
_dorsolateral prefrontal association cortex
IT IS AN ASSOCIATION CORTEX
– it communicates with secondary and primary motor cortex, as well as to the frontal eye field. Plays an important role to identify and respond to objects, initiate voluntary movements
_posterior parietal association cortex
IT IS AN ASSOCIATION CORTEX
– plays an important role indirecting behaviour by providing spatial information and in directing attention, it receives input from more than one sensory input (visual, auditory and somatosensory system) , most of the output goes to the secondary (non-primary) motor cortex or to the dorsolateral prefrontal association cortex
_DAMAGE – it can produce a variety of deficits, including deficts in the perception and memory of spatial relationships, in accurate reaching and grasping , in the control of eye movement, and in attention
_apraxia – difficulty making specific movements when they are requested to do so, if they don’t think about it they are able to move. Usually caused by unilateral damage to the left posterior parietal cortex
_contralateral neglect – disturbance of a patient’s ability to respond to stimuli on the side of the body opposite (contralateral) to the side of a brain lesion in the absence of simple sensory or motor deficits. Patients act as their left side of the world doesn’t exist, they often fail to appreciate that they have a problem, acting as it doesn’t exist
_reciprocal innervation
– antagonistic muscles are innervated in a way that permits a smooth, unimpeded motor response: when one is contracted the other relaxes
MOTOR PATHWAYS IN THE SPINAL CORD
_lateral group
They control less automatic movements. They’re involved in independent limb movements, particularly movements of hands and fingers. Independent means that the right and left limbs make different movements or one limb moves while the other stays there
_corticobulbar tract
_rubrospinal tract
_corticolspinal tract
MOTOR PATHWAYS IN THE SPINAL CORD _ventromedial group
They control more automatic movements (gross movements of the muscles of the truck and coordinated trunk and limb movements involved in posture and locomotion. These tracts control motor neurons in the ventromedial part of the spinal cord gray matter.
_reticulospinal tract
_ventral corticospinal tract
_vestibulospinal tract
_tectospinal tract
_reticulospinal tract
VENTROMEDIAL PATHWAYS – it descends from the reticular formation in two tracts to act on the motor neurons supplying the trunk and proximal limb muscles. It is involved mainly in locomotion and postural control, although it does have other effects as well. Mediates autonomic functions, thus it is an independent extrapyramidal tract
_ventral corticospinal tract
VENTROMEDIAL PATHWAY – it descends from the reticular formation in two tracts to act on the motor neurons supplying the trunk and proximal limb muscles. It is involved mainly in locomotion and postural control, although it does have other effects as well. It is a dependent pyramidal tract.
_structures that interact with it
_vestibular nucleus
_tectum
_reticular formation
_motor nuclei of cranial nerves
IMAGE PATHWAYS POSTERIOR PARIETAL ASSOCIATION CORTEX
IMAGE PATHWAYS DORSOLATERAL PREFRONTAL ASSOCIATION CORTEX
IMAGE PATHWAYS OF SECONDARY MOTOR CORTEX
IMAGE LATERAL MOTOR PATHWAYS SPINAL CORD
IMAGE VENTROMEDIAL MOTOR PATHWAYS SPINAL CORD
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_withdrawal reflex
– the contraction of a muscle when a painful stimulus is encountered, it is NOT monosynaptic and it takes longer (an interneuron is involved as well, more muscles are involved and thus move. IT DOES NOT GO TO THE BRAIN
