169 Questions
Which area of the motor cortex is responsible for controlling muscles in the hand and muscles concerning speech?
Primary cortex
What is the function of the motor cortex?
Sending commands to the skeletal muscle
What can somatic signals do to muscle contraction?
Enhance muscle contraction
How many areas is the motor cortex divided into?
3
Where does the primary cortex begin?
Laterally in the sylvian fissure
Which area is responsible for motor imaging and contains mirror neurons?
Premotor areas
Where are supplemental areas located?
In the longitudinal fissure
Which area is known as Broca's area and is responsible for motor speech?
Motor speech area
Which area controls bilateral movements such as climbing or grasping an object with both hands?
Supplemental areas
Which area has more complex patterns compared to the primary motor cortex?
Premotor areas
Which tract originates in the red nucleus?
Rubrospinal tract
Which cells are found only in the motor cortex and project down through the spinal cord onto motor neurons?
Betz cells
Which lesions can cause a dramatic increase in extensor tone called decerebrate rigidity?
Lesions above the pons but below the midbrain
Which tract originates in the superior colliculus?
Tectospinal tract
Where do pyramidal tracts decussate?
Lower medulla
Which cells are referred to as magnocellular cells?
Betz cells
Which laminae perform most of the intracortical association functions?
Lamina I, II, and III
Which cells give rise to the output fibers of the cerebral cortex?
Pyramidal and Fusiform cells
Where do most incoming sensory signals terminate within the cerebral cortex?
Lamina IV
Which layer of the primary motor cortex contains pyramidal cells?
Lamina V
Which laminae receive inputs in the primary motor cortex?
Lamina II and IV
Which type of neurons in the red nucleus are more abundant?
Dynamic neurons
Which type of neurons fire at a slower rate and maintain the force of contraction for as long as needed?
Static neurons
Which type of neurons are excited for short periods of time and cause rapid development of force?
Dynamic neurons
Which cells are responsible for transmitting both dynamic and static signals?
Pyramidal cells
Which descending tracts terminate mainly on interneurons and motor nerves?
Corticospinal and rubrospinal tracts
Where is the red nucleus located?
Mesencephalon
Which tract decussates in the lower brain stem and goes into the lateral columns of the spinal cord?
Rubrospinal tract
Which nucleus serves as an alternative pathway for transmitting cortical signals to the spinal cord?
Red nucleus
Which cells give rise to the rubrospinal tract?
Magnocellular cells
Where does the rubrospinal tract originate?
Red nucleus
What is the function of the red nucleus?
Motor coordination
Which portion of the red nucleus is similar in size to Betz cells?
Magnocellular portion
Which lobe of the brain is important for language comprehension?
Temporal lobe
Which area is responsible for word formation in language?
Broca's area
What is the consequence of damage to the angular gyrus in the occipital lobe?
Alexia
Which area is responsible for language comprehension?
Wernicke's area
What is the consequence of damage to Broca's area?
Inability to vocalize words
Which area within the parieto-occipitotemporal area is responsible for visual reading of words?
Angular gyrus
What is the consequence of damage to the arcuate fasciculus?
Impaired speech comprehension
Where are names of objects learned through?
Auditory input
Which area of the brain is responsible for connecting the speech motor areas with the language comprehension area?
Arcuate fasciculus
How are the physical nature of objects learned according to the text?
Through visual input
Which two cortical areas are specialized for language?
Broca's area and Wernicke's area
Where is Wernicke's area located?
Upper part of temporal lobe
How is the understanding of the meaning of words achieved?
Through Wernicke's area
Which tract connects Wernicke's area to Broca's area?
Arcuate fasciculus
What is the consequence of damage to Broca's area?
Inability to produce speech or find a word
What is the consequence of damage to Wernicke's area?
Fluent production of speech with poor comprehension
Which hemisphere is dominant for right-handed people?
Left
Which hemisphere can be dominant for left-handed people?
Right
Which area is important for interpreting complicated meanings of sensory experiences?
Wernicke's area
Which area is used for speaking a written word but not for speaking a heard word?
Angular gyrus
What do fibers in the corpus callosum provide between the two cerebral hemispheres?
Bidirectional information
What types of functions may the non-dominant hemisphere be used for?
Interpreting music and body language
Which disease is the most common form of dementia in the United States?
Alzheimer's disease
Which neurotransmitter is associated with the loss of cholinergic neurons in Alzheimer's disease?
Acetylcholine
Where does degeneration occur in Alzheimer's disease?
Hippocampus
What are the microscopic findings in Alzheimer's disease?
Amyloid-beta plaques and neurofibrillary tangles
Which disease is a leading cause of death from cardiovascular disease in the United States?
Stroke
What is the importance of time in stroke care?
Early care leads to better outcomes
Which type of stroke is caused by an occlusion of a cerebral blood vessel resulting in an infarction?
Ischemic stroke
What is the main cause of hemorrhagic stroke?
Chronic hypertension
Which symptoms can be induced by a stroke?
Paralysis, numbness, and sensory deficits on one side of the body
What can cause an ischemic stroke?
Atherosclerosis, cerebral embolism, or occlusion of a small cerebral vessel
What is the main cause of intracerebral hemorrhage?
All of the below
Which artery supplies the largest portion of the left cerebral hemisphere?
Middle cerebral artery
What symptoms can occur as a result of an occlusion in one of the distal stems of the MCA?
All of the above
What structures can be affected by an infarction in the internal capsule?
Basal ganglia, putamen, and caudate
Which area of the brain is responsible for speech impairment in motor aphasia?
Broca's area
Which artery is associated with occlusion that can cause visual field defects and deviation of the head and eyes towards the side of the lesion?
Middle cerebral artery (MCA)
Which direction do the head and eyes deviate towards when the MCA is occluded?
Towards the side of the lesion
Which area of the cerebellum is responsible for controlling dynamic balance and eye movements?
Vestibulocerebellum
Which area of the cerebellum receives information from the motor cortex and periphery to coordinate movement?
Spinocerebellum
Which area of the cerebellum helps to plan, sequence, and time complex movements?
Cerebrocerebellum
Which zone of the cerebellum is responsible for motor coordination of the axial body, neck, shoulders, and hips?
Vermis
Which zone of the cerebellum controls muscle contractions in the upper and lower limbs, and face?
Intermediate zone
Which zone of the cerebellum joins with the cerebral cortex in overall planning of sequential motor movements?
Lateral zone
Which zones receive information from the cerebral cortex and do not have topographs?
Lateral zones
Which tracts mainly go to the lateral zones?
Pontocerebellar tracts
Which tracts come from the periphery and terminate in vermis and intermediate zones?
Spinocerebellar tracts
Which tracts receive information from the periphery and terminate in the vermis and intermediate zones?
Spinocerebellar tracts
What type of signals do the dorsal spinocerebellar tracts receive?
Proprioceptive signals
Where does the ventral spinocerebellar tract receive information from?
Anterior horns of the spinal cord
Which structures receive efferent signals from the cerebellum?
Thalamus and basal ganglia
Where do deep cerebellar nuclei receive signals from?
Cerebellar cortex and deep sensory afferents
What is the function of the cerebellar cortex in the input signal pathway?
Divides the input signal and sends it to the deep nuclei and cortex
Which layer of the cerebellum is the innermost?
Granular layer
What type of output signal does the purkinje cell layer of the cerebellum provide?
Inhibitory
What type of fibers provide excitatory input to the cerebellar cortex?
Climbing and Mossy fibers
What is the function of the complex circuit in the cerebellum?
Inhibiting agonist and antagonist muscles
Which cells in the cerebellum are responsible for modulating the activity of circuits that go to the deep cerebellar nuclei?
Purkinje cells
What type of fibers provide excitatory input to the Purkinje cells in the cerebellum?
Climbing fibers
What is the function of cerebellar interneurons, except for granule cells?
Inhibitory
What is the consequence of damage to the angular gyrus in the occipital lobe?
Language comprehension difficulties
What is the primary output from the cerebellar cortex?
GABA
What determines the output of the cerebellar cortex?
Deep nuclear cells
What is the role of the deep nuclear cells in the cerebellum?
Receive input from the periphery and brain
What is the function of the complex spikes in the cerebellum?
Elicit multiple excitatory bursts
Which part of the cerebellum is responsible for providing anticipatory correction?
Vestibulocerebellum
What is the function of the climbing fiber in the cerebellum?
To alter the long-term sensitivity of the Purkinje cell
Which part of the cerebellum is the oldest?
Vestibulocerebellum
Which part of the cerebellum provides information on the body's balance and equilibrium?
Vestibulocerebellum
What is the function of the Purkinje cells in the cerebellum?
To respond to excitatory input from the parallel fibers
What is required for learning to occur in the cerebellum?
Neuroplasticity
What can influence the function of the vestibulocerebellum?
Ethanol and drugs
Which part of the cerebellum is responsible for smooth, coordinated movements of muscles in the distal limbs?
Spinocerebellum
What information does the intermediate zone of the cerebellum receive when a movement is performed?
A and C
What is the function of the cerebellum in relation to movement?
To dampen movements
What effect does cerebellum dysfunction in the spinocerebellum have on arm movements?
It causes the arm to oscillate back and forth past its intended point
Which part of the cerebellum acts as a comparator and compares the intended movement with the actual movement?
Intermediate zone
Where does the intermediate zone of the cerebellum send signals to after comparing the intended movement with the actual movement?
A and B
What must be overcome before a movement can be stopped?
Momentum
What is the term for the effect of cerebellum dysfunction in the spinocerebellum causing the arm to oscillate back and forth past its intended point?
Intention tremor or action tremor
Which part of the cerebellum is responsible for planning, sequencing, and timing complex movements?
Cerebrocerebellum
What is the main function of the premotor area and sensory areas in movement planning?
Provide appropriate motor signals
What is the consequence of damage to small areas of the lateral zones?
Coordination of movements is unaffected
What is dysmetria?
Overshooting and overcompensating movements
Which areas of the cerebellum have the most communication with the premotor area and primary and association somatosensory areas?
Lateral zones
What is the role of the cerebrocerebellum in coordinating patterns such as writing, running, and talking?
Time different movements
What type of dysfunction usually occurs when one or more of the deep cerebellar nuclei are damaged?
Serious dysfunction
What can cause dysmetria and ataxia due to the inability to interpret feedback information from the moving parts of the body?
Lesions in the spinocerebellar tracts
What is the function of the basal ganglia in movement coordination?
Provide appropriate motor signals
Which part of the brain helps to provide extra motor force and stop movements at the intended point?
Cerebellum
What is the main function of the cerebellum in relation to muscle contractions?
Programming muscle contractions in advance
Which of the following is a clinical manifestation of cerebellar lesions within the spinocerebellum?
Dysdiadochokinesia
What is the term for the lack of coordination due to errors in rate, range, force, and direction of movement?
Ataxia
Which of the following is a clinical manifestation of cerebellar lesions within the vestibulocerebellum?
Cerebellar nystagmus
What is the term for the inability to stop a movement?
Rebound phenomenon
What is the function of the cerebellum with the spinal cord?
Enhance the stretch reflex
What is the term for the failure of progression in talking due to the inability to coordinate mouth, larynx, vocal cords, and respiratory system?
Dysarthria
What is the term for the lack of coordination due to errors in rate, range, force, and direction of movement?
Ataxia
What is the term for the inability to perform rapid alternating movements?
Dysdiadochokinesia
Which circuit inhibits skeletal muscle motor activity and results in hypokinetic activity?
Putamen circuit
Which circuit increases skeletal muscle motor activity and results in hyperkinetic activity?
Caudate circuit
Which circuit controls cognition of sequences of motor activity?
Caudate circuit
Which circuit operates in a push-pull manner?
Both circuits
Which circuit is the dominant system?
Putamen circuit
Which system results in lowered motor activity when stimulated?
Putamen circuit
Which disease is an exception to the normal effect of interrupting the indirect pathway?
Parkinson's disease
Which structures make up the dorsal striatum?
Caudate nucleus and putamen
What type of neurons are mainly found in the dorsal striatum?
GABA-producing neurons
Which receptors stimulate the nerves of the direct pathway in the basal ganglia?
D1 receptors
Which receptors inhibit the nerves of the indirect pathway in the basal ganglia?
D2 receptors
Which neurotransmitter pathways go from the cortex to the caudate and putamen?
Acetylcholine pathways
What is the consequence of damage to the putamen circuit or the globus pallidus?
Athetosis
What type of movements are associated with lesions in the subthalamus?
Hemiballismus
What type of movements are associated with multiple lesions in the putamen?
Chorea
What is the effect of cholinergic drugs within the CNS?
Decrease in motor activity
Which neurotransmitter pathways stimulate the indirect pathway in the basal ganglia?
Acetylcholine
Which neurotransmitter is responsible for hyperpolarization or IPSPs in the basal ganglia?
GABA
Which neurotransmitter pathways go from the cortex to the caudate and putamen?
Acetylcholine
What type of signals do glutamate pathways carry in the basal ganglia?
Excitatory
Which areas provide information to the putamen circuit in the basal ganglia?
Prefrontal, premotor, and somatosensory
Where does the output of the putamen circuit in the basal ganglia go to?
Premotor and primary motor cortex
Which areas do the ancillary circuits in the basal ganglia connect to?
Subthalamus and substantia nigra
Which part of the brain is responsible for changing the timing and intensity of movements based on somatosensory information?
Basal ganglia
What is the term for the inability to accurately perceive objects due to lesions in the posterior parietal cortex?
Agnosia
What is the term for the neglect of the left side of the body due to lesions in the right parietal lobe?
Personal neglect syndrome
What is the name of the disease characterized by the loss of dopaminergic neurons or lesions within the substantia nigra?
Parkinson's disease
What are some symptoms of Parkinson's disease caused by the loss of dopaminergic neurons?
Muscle rigidity, dysphagia, speech disorders
What is the term for the feeling of trudging through water or a sense of heaviness experienced by patients with Parkinson's disease?
Bradykinesia
What type of drugs are typically used to treat Parkinson's disease by blocking peripheral metabolism of L-DOPA?
Inhibitors of dopamine decarboxylase
Which syndrome is characterized by the loss of inhibition in CNS circuits, leading to easy oscillation?
Hypokinetic syndrome
What are anticholinergic drugs useful against in Parkinson's disease?
Muscle rigidity and resting tremor
What is the term for the loss of ability to perceive objects accurately through normal functioning sensory inputs?
Agnosia
Which neurotransmitter pathways go from the caudate or putamen to the globus pallidus and substantial nigra?
GABA pathways
Which neurotransmitter pathways go from the substantia nigra to caudate nucleus and putamen?
Dopamine pathway
What is the role of glutamate pathways in the brain?
They balance out inhibitory signals
Study Notes
Motor Cortex
- The area responsible for controlling muscles in the hand and muscles concerning speech is the ventralateral area of the motor cortex.
- The motor cortex is responsible for controlling voluntary movements.
- Somatic signals can increase or decrease muscle contraction.
- The motor cortex is divided into four areas.
Primary Motor Cortex
- The primary motor cortex begins in the precentral gyrus.
- The primary motor cortex is responsible for controlling simple movements.
Premotor Cortex
- The premotor cortex is responsible for motor imaging and contains mirror neurons.
- The premotor cortex is located in the precentral gyrus and frontal lobe.
Supplemental Motor Cortex
- The supplemental motor cortex is located in the superior frontal gyrus and precentral gyrus.
- The supplemental motor cortex is responsible for controlling bilateral movements such as climbing or grasping an object with both hands.
Broca's Area
- Broca's area is responsible for motor speech and is located in the inferior frontal gyrus.
- Damage to Broca's area can result in motor aphasia.
Pyramidal Tracts
- The pyramidal tracts originate in the primary motor cortex and decussate in the medulla oblongata.
- The pyramidal tracts include the corticospinal and corticobulbar tracts.
Betz Cells
- Betz cells are found only in the motor cortex and project down through the spinal cord onto motor neurons.
- Betz cells are responsible for transmitting signals to the spinal cord.
Red Nucleus
- The red nucleus is located in the midbrain and is an alternative pathway for transmitting cortical signals to the spinal cord.
- The red nucleus gives rise to the rubrospinal tract.
- The rubrospinal tract decussates in the lower brain stem and goes into the lateral columns of the spinal cord.
- The rubrospinal tract is responsible for transmitting signals to the spinal cord.
Language
- The lobe of the brain important for language comprehension is the temporal lobe.
- The area responsible for word formation in language is Broca's area.
- The area responsible for language comprehension is Wernicke's area.
- Wernicke's area is located in the posterior superior temporal gyrus.
- The arcuate fasciculus connects Wernicke's area to Broca's area.
Stroke
- The most common form of dementia in the United States is Alzheimer's disease.
- The main cause of ischemic stroke is an occlusion of a cerebral blood vessel resulting in an infarction.
- The main cause of hemorrhagic stroke is a rupture of a cerebral blood vessel.
- The middle cerebral artery supplies the largest portion of the left cerebral hemisphere.
Cerebellum
- The cerebellum is responsible for controlling dynamic balance and eye movements.
- The cerebellum receives information from the motor cortex and periphery to coordinate movement.
- The cerebellum helps to plan, sequence, and time complex movements.
- The vermis is responsible for motor coordination of the axial body, neck, shoulders, and hips.
- The intermediate zone controls muscle contractions in the upper and lower limbs, and face.
- The lateral zone joins with the cerebral cortex in overall planning of sequential motor movements.
- The dorsal spinocerebellar tracts receive proprioceptive signals from muscle spindles and Golgi tendon organs.
- The ventral spinocerebellar tract receives information from the spinal cord.
- The cerebellar cortex is responsible for providing anticipatory correction.
Test your knowledge of the motor cortex and its divisions with this quiz. Learn about the primary, premotor, and supplementary areas, as well as their functions in controlling muscles and sending commands to skeletal muscles. Discover how the motor cortex plays a role in stabilizing joints and controlling hand movements and speech.
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