Lec 02- Brain Function Flashcards
How many neurons are in the cerebral cortex?
100 billion
What are the 3 shapes of neurons?
- granular (stellate)
- fusiform
- pyramidal
What are the characteristics of granular neurons?
- Short axons
- Interneurons
- Excitatory and inhibitory
What causes granular neurons to be excitatory?
glutamate
What causes granular neurons to be inhibitory?
GABA
Which are the smaller output neurons?
fusiform
Which are the larger output neurons?
pyramidal
Which cerebral cortex layer is responsible for the termination of most incoming specific sensory signals?
4
Which cerebral cortex layer is the origin of most output signals?
5 and 6
Which cerebral cortex layer has fibers that go to the thalamus?
6
Which cerebral cortex layers have intercortical association functions?
1, 2, 3
What happens to the functions of the corresponding cortical areas when the thalamic connections are cut?
they become almost entirely lost
What are the 2 sensation areas?
- lateral geniculate body
- medial geniculate body
What is the later geniculate body do?
- Relays visual information from the retina to the brain
- Thalamus
What is the medial geniculate body important for?
- Hearing
- Wernicke’s area
Which cortical area has direct connections with specific muscles?
Primary motor area
Which cortical area detects specific sensations?
Primary sensory area
Which cortical area provides patterns of motor activity?
secondary motor area
Which cortical area analyzes meanings of specific sensory signals?
secondary sensory area
What do association areas do?
receive and analyze signals simultaneously from multiple motor and sensory cortices
What are the 3 major association areas?
- Parieto-occipitotemporal
- Prefrontal
- Limbic
What are the 4 sub-areas of the Parieto-occipitotemporal association area?
- Area for analysis of spatial coordinates
- Wernicke’s area
- Angular gyrus area
- Area for naming objects
What are the functions of the prefrontal association area?
- Receives pre-analyzed sensory information necessary for planning effective movement
- Carries out “thought” processes in the mind
Where does the sensory information go after entering the prefrontal association area?
passes through caudate portion of the basal ganglia
What does Broca’s area do?
provides circuitry for word formation
What side is the Broca’s area almost always dominant on?
Left side of brain
What is the limbic association area concerned with?
- behavior
- emotions
- motivation
What is Wernicke’s area involved in?
language comprehension
What is the occipital portion of facial recognition area next to?
visual cortex
What association area is the temporal portion of the facial recognition area closely associated with?
limbic system
Extensive damage to what area results in prosopagnosia (inability to recognize faces)?
facial recognition area
What association areas all meet one another in the posterior part of the superior temporal lobe?
- somatic
- visual
- auditory
What area is especially developed in the dominant side of the brain?
Area of Confluence
In right-handed people, what side is dominant and what is it referred to as?
- Left side of the brain
- Werknicke’s area
Which area plays the greatest single role of any part of the cerebral cortex for intelligence?
Wernicke’s
What happens when Wernicke’s area is activated?
can call forth complicated memory patterns involving more than one sensory modality
What 2 areas are more developed in the left hemisphere in 95% of the population?
- Wernicke’s area
- The angular gyrus
Where are the motor areas for controlling hands located?
Left hemisphere in 90% of people
What are the consequences of a prefrontal lobotomy?
Cannot:
- solve complex problems
- string together sequential tasks to reach complex goals
- do several parallel tasks at the same time
- carry through long trains of thought
Decreased level of aggressiveness (ambition)
Inappropriate social responses
Loss of purpose while performing usual motor pattern functions
What can happen if the brain’s working memory is normal?
- prognostication
- planning for future
- delay in response to incoming sensory signals
- consider consequences of motor actions
- solve complicated mathematical, legal, or philosophical problems
- control of activities in accord with moral law
What are the major functions of the limbic system?
- gray matter
- respond to fear
- rage and aggression
What is the major commissure between the 2 brain hemispheres?
corpus callosum
What 3 things will happen if the corpus callosum is cut?
- Blocking of transfer of information from Wernicke’s > Nondominant motor cortex
- Prevention of transfer of somatic and visual information from Right Hemisphere > Wernicke’s area
- 2 Entirely separate conscious portions of the brain
What areas are activated when speaking a heard word?
- Broca’s area
- Primary auditory area
- Wernicke’s area
- Arcuate fasciculus
What areas are activated when speaking a written word?
- Broca’s area
- Wernicke’s area
- Angular gyrus
What is declarative memory?
memory of various details of an integrated though
What memories might be included in declarative memory?
- surroundings
- time relationships
- causes of experience
- meaning of experience
- deductions as a result of experience
What type of memory is associated with motor activities?
reflexive (skill) memory
What memory is the memory of a phone number?
short-term memory
lasts only as long as the person thinks of number or facts (seconds)
What memory lasts many minutes or weeks?
intermediate long-term memory
Which memory may become long-term memory (more permanent) if memory traces are activated enough?
intermediate long-term memory
What is studied in Aplysia?
mechanism for facilitation
What causes serotonin release at the facilitator synapse?
the stimulation of facilitator presynaptic terminal at the same time that sensory terminal is stimulated
What receptors in the sensory terminal membrane activate adenyl cyclase»_space; cAMP?
serotonin receptors
What happens after serotonin receptors in the sensory terminal membrane activate adenyl cyclease?
- cAMP activates part of K+ channel
- K+ channel is blocked for minutes to weeks
What greatly prolongs AP in synapse terminal?
lack of K+ conduction
What causes prolonged activation of Ca channels?
prolonged AP in synapse terminal
What prolongs transmitter release?
prolonged activation of Ca channels due to prolonged AP in synapse because of lack of K+ conduction
What turns short-term memory into long-term memory?
hippocampus
What are the 4 structural changes of long-term memory?
Changes in structures of dendritic spines
Increase in:
- Vesicle release sites for secretion of transmitter substance
- Number of transmitter vesicles released
- Number of presynaptic terminals
