Flashcards in Brain Function Deck (40):
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
Limbic association area
Which association area is an area of analysis of spatial coordinates?
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?
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?
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?
1. Stimulation of presynaptic terminal - serotonin is released.
2. Serotonin receptors activate cAMP
3. cAMP activates part of a potassium channel, which blocks it.
4. A greatly prolonged action potential occurs.
5. Prolonged activation of calcium channels occurs.
6. Neurotransmitter release is prolonged.
What are structural changes associated with long term memory?
1. Increase in vesicle release sites for secretion of transmitter substance.
2. Increase in number of transmitter vesicles released.
3. Increase in number of presynaptic terminals.
4. Changes in structures of the dendritic spines.
Memories of experiences, surroundings, and time are an example of what type of memory?
Riding a bike involves what type of memory?
Reflexive (skill) memory
Memory of a Newly learned telephone number is an example of what type of memory?
It lasts only as long as a person thinks of numbers or facts.
Remembering material for an upcoming physiology exam is an example of what type of memory?
What are the three types of cortical neurons?
What is the function of the angular gyrus?
It makes the meaning out of visually perceived words and conveys it to Wernicke's area.
In its absence, a person can still have excellent language comprehension through hearing, but not through reading.
In what association area is Wernicke's area located?
Parieto-occipitotemporal association area.
You encounter a patient who has suffered a stroke. After the stroke, the patient is able to hear and recognize different words, but is unable to arrange the words into a coherent thought. What area of the brain is most likely affected?
You encounter a stroke patient who is capable of deciding what he wants to say, but he cannot make the vocal system emit words instead of noises. What area of the brain is most likely affected?
What is the general mechanism for storing memories in the brain?
Memories are stored in the brain by chaning the basic sensitivity of synaptic transmission between neurons as a result of previous neural activity.
What are memory traces?
New or facilitated pathways that result from changing the basic sensitivity of synaptic transmission between neurons as a result of prevous neural activity.
What is meant when a greater share of our memories are negative and not positive?
It means that our brain has the capability to ignore information that is not important. This is done by inhibiting synaptic pathways for such information. The result is habituation, which is a type of negative memory.
What is the process of intermediate long-term memory?
When a sensory signal is stimulated repeatedly but without stimulation of a facilitator terminal, signal transmission at first is great, but becomes less and less intense with repeated stimulation until transmission almost ceases.
What is facilitation?
Facilitation occurs when a transmitted signal into a postsynaptic neuron becomes stronger and stronger, up to several weeks even without further stimulation of a facilitator terminal.