C12 5-6 Flashcards
Where is the Primary motor cortex located?
Precentral gyrus of the frontal lobe.
What are the three main motor areas of the cortex?
Primary motor cortex, Broca’s area, Frontal eye field
What is the function of the primary motor cortex?
consciously control precise or skilled voluntary movement of skeletal muscle.
Contains pyramidal neurons - the axons of the neurons project contralaterally either in brain stem or spinal cord - thus, the L primary motor cortex controls the R-side voluntary muscles and vv.
What is a motor homunculus?
A diagram that illustrates the distribution of the primary motor cortex innervation to various body parts.
Where is the Broca’s area located?
Anterior to the inferior region of the premotor area.
What is the function of the Broca’s area?
Regulate patterns of breathing
control muscular movements for vocalization.
How does the Broca’s area control speech?
- From Broca’s, impulses pass –> premotor regions that control the muscle of the larynx/pharynx/mouth.
- Premotor area impulses result in specific, coordinated, muscle movements.
- Simultaneously, from Broca’s, impulses pass to the primary motor area.
- From the primary motor area, impulses control the breathing muscles to regulate the proper flow of air passing the vocal cords.
What does injury to language areas
result in?
Aphasia (without speech) Damage to Broca’s results in nonfluent aphasia (inability to articulate or form words)
Where is the frontal eye field located?
anterior to the premotor cortex, superior to broca’s.
What is the function of the frontal eye field?
Controls voluntary movement of the eyes.
What does damage to areas of the primary motor cortex result in?
Paralyzes muscles controlled by those areas. Only voluntary movement - muscles can still contract reflexively.
7 sensory areas?
somatosensory, visual, auditory, olfactory, gustatory, visceral, vestibular
Where is the Primary somatosensory cortex located?
Postcentral gyrus of the parietal lobe.
What does the primary somatosensory cortex do?
Receives general somatic sensory information from proprioceptors (body position) as well as touch, pressure, pain and temperature receptors.
Then, spatially discriminate and identify the body region being stimulated.
Where is the primary visual cortex located?
Occipital lobe