Online Module 1 Flashcards
(33 cards)
Where is the somatosensory cortex located?
Posterior to the central sulcus, on the parietal lobe (post central gyrus)
In an ascending pathway, where does information coming from the Left terminate on the brain?
Terminates on the Right somatosensory cortex
What is the function of the Spinothalamic tract (anterolateral system)?
conveys pain, temperature, tickle, itch, crude touch
Where are the 1st, 2nd and 3rd order neurones of the spinothalamic tract?
1st: dorsal root ganglion
2nd: dorsal horn
3rd: thalamus
Where or when does the decussation occur in a spinothalamic tract?
After the 2nd order neuron synapse, at the anterior white commissure
What is the function of the Dorsal column system?
conveys fine touch and proprioception
Where are the 1st, 2nd, and 3rd order neurones of the Dorsal column-medial lemniscus pathway?
1st: dorsal root ganglion
2nd: brain stem (medulla oblongata)
3rd: thalamus
Where or when does the decussation occur in a dorsal column-medial lemniscus pathway?
After 2nd order neurone synapses at the brainstem (medulla oblongata)
Where is the primary motor cortex located?
Anterior to the central sulcus on the parietal lobe (precentral gyrus)
What is the function of the corticospinal pathway?
Fine precise movements (axial and limb motor)
Where is the upper and lower motor neurone located in the corticospinal pathway?
Upper: Primary motor cortex
Lower: anterior horn of grey matter
Where does decussation occur in a lateral corticospinal pathway and which neurone decussates?
Decussation of the upper motor neurone at the lateral corticospinal tract. Decussation occurs before synapse with the lower motor neurone
What is the function of the corticobulba pathway?
Provides motor control of the head and neck
Where do the 1st and 2nd order neurone synapse in the corticobulba pathway?
Synapse occurs immediately after decussation at the brainstem. Lower motor neurone leaves via spinal nerves
What is the function of the brainstem pathway (descending pathways)?
Provides basic control like posture, balancing, walking
Where do neurones originate from in the brainstem pathway?
At the brainstem
Do the upper motor neurones of the brainstem pathway project to appropriate spinal cord segments contralaterally or ipsilaterally?
ipsilaterally
What occurs at the highest level of motor control? What areas are involved?
Planning of movement: intended movement initiation, forming complex motor plan.
Premotor/motor association, parts involved in memory and emotion
What occurs the the middle level of motor control? What areas are involved?
Programming of movement: plan goes to a small number of programs projected along corticospinal pathway and or brainstem pathway
Sensorimotor cotex, basal nuclei, cerebellum, brainstem, thalamus
What occurs at the lowest level of motor control? what areas are involved?
Execution of movement: determined by force, tension sensed by proprioception and reflex
Brainstem, spinal cord, interneurons
What is the importance of the cerebellum in motor control? What pathway does it influence?
Compares intended movement to actual movement. large influence on brainstem nuclei, thus the brainstem pathway
What happens to motor control when the cerebellum is damaged?
Tremor during movement and poor hand eye coordination due to inability to compare incoming signals to outgoing signals.
Unstable posture, awkward walking gait (brainstem pathway)
What is the importance of the basal nuclei in motor control?
Supports wanted movement, and suppresses unwanted movement. Ensures programs leading to actual movement are appropriately formed.
What happens to motor control when the basal nuclei is damaged?
Tremor at rest due to lack of inhibition of unwanted movement.
Muscle rigidity at rest
Difficulty in initiating/stopping movement
Walking-shuffling gait (little arm movement)
Little facial expression
