Brain Function Flashcards
What are granular (stellate) neurons?
Interneurons with short axons. They are both excitatory (glutamate) and inhibitory (GABA).
What are fusiform neurons?
Smaller output neurons
What are pyramidal neurons?
Large output neurons
What is found in cerebral cortex layer IV?
Termination of most incoming specific sensory signals.
What is found in cerebral cortex layers V and VI?
Origin of most output signals
Fibers to thalamus from VI
What is in cerebral cortex layers I, II and III?
Intracortical association functions.
Describe the relationship of the thalamus to the cerebral cortex.
When thalamic connections are cut, the functions of corresponding cortical areas become almost entirely lost.
Define the thalamocortical system
A system that consists of connections from the thalamus to the cortex.
Distinguish between primary motor and sensory areas.
Primary motor areas have direct connections with specific muscles.
Primary sensory areas detect specific sensations.
Compare the secondary areas with the primary centers.
The secondary areas provide patterns of motor activity and analyze meanings of specific sensory signals.
Primary motor areas detect connections with specific muscles and detect specific sensations.
List the functions of the secondary areas
Secondary motor: provides patterns of motor activity
Secondary sensory: analyzes meaning of specific sensory signals.
List the functions of the association areas.
Associaton areas receive and analyze signals simultaneously from multiple motor and sensory cortices.
What are the association areas?
Parieto-occipitotemporal association area
Prefrontal association area
Broca’s area
Wernicke’s area
Limbic association area
Which association area is an area of analysis of spatial coordinates?
Parieto-occipitotemporal area.
It is also an area for naming objects.
What is the function of the prefrontal association area?
It receives preanalyzed sensory information (especially concerning spatial coordinates) necessary for planning effective movements.
It carries out “thought” processes in the mind.
What is the function of Broca’s area?
It provides circuitry for word formation
What is the function of the limbic association area?
It is concerned with behavior, emotions and motivation.
What is the function of Wernicke’s area?
Language comprehension.
It is also an area where somatic, visual and auditory association areas all meet one another in the posterior part of the superior temporal lobe.
Which area plays the greatest single role o an part of the cerebral cortex for intelligence?
Wernicke’s area.
Activation of this allows for using complicated memory patterns involving more than one sensory modality.
Compare the dominant hemisphere with the nondominant hemisphere.
Wernicke’s and Broca’s area are more dominant in the left hemisphere.
Motor areas for controlling hands are also dominant in the left hemisphere.
You encounter a patient who cannot solve complex problems. They are also unable to do several parallel tasks at the same time, and are unable to carry long trains of thought. They also display inappropriate social responses. What may have caused these symptoms?
A prefrontal lobotomy.
What do prefrontal lobotomies tell us about the prefrontal lobe?
The prefrontal lobe is important for solving complex problems and to solve them simultaneously.
The prefrontal lobe is impotant for planning for the future, ability to consider consequences of motor actions, and to control activities in accord with moral law.
Describe the results of cutting the corpus callosum.
Blocking of transfer of information from Wernicke’s area to nondominant motor cortex.
Preventation of the transfer of somatic and visual information from the right hemisphere into Wernicke’s area.
Results in two entirely separate conscious portions of the brain.
What is the mechanism for faciliation?
- Stimulation of presynaptic terminal - serotonin is released.
- Serotonin receptors activate cAMP
- cAMP activates part of a potassium channel, which blocks it.
- A greatly prolonged action potential occurs.
- Prolonged activation of calcium channels occurs.
- Neurotransmitter release is prolonged.
