Brainstem Functions Flashcards
Why is the brainstem important?
- Major ascending and descending pathways project there
- Nuclei of cranial nerves II-X and XII are there
Reticular formation
a group of nuclei scattered throughout the brainstem involved in regulating motor functions
RAS - reticular activating system
regulates the sleep-wake cycle; can be stimulated by visual and acoustics stimuli and mental activities
damage results in coma
Two categories of motor output from the brainstem
somatic motor
parasympathetic
Somatic motor output and reflexes
involved in voluntary and reflex eye movements
muscle control of chewing; keep tongue out of the way
controls cranial nerve VII (facial)
controls cranial nerve iX and X (swallowing and speech)
Parasympathetic output and reflexes
Contriction of puil
Sneeze
Salivation
Gag reflex, cough reflex
2 major areas of brain for speech
Wernicke’s Area > understand and formulate
coherent speech
Broca’s Area > initiates movements necessary for speech
What structure connects the Wernicke and Broca area?
Arcuate (a bundle of neurons)
What structures share sensory information between teh right and left hemispheres of the brain?
Commissures
Which the largest comissure?
Corpus callosum
Electroencephalogram (EEG)
a device that reocrds the brain’s electrical activity.
can’t detect individual action potential, but can detect simultaneous action potentials in large number neurons
Different levels of consciousness
Alpha waves > awake, but in a quiet, restful state
Beta waves > occur during intense mental activity
Theta waves > usually occur in children
Delta waves > infants, sever brain disorders, or deep sleep
Aphasia
Damage to language areas of cerebral cortex. Most common cause is a stroke
Types of aphasia
Receptive aphasia > lesion to wernicek area, defective auditory & visual comprehsnio of language
Jargon aphasia > a person speak fluently but intelligibly lesion in tracts between wrnicke and broca
Conduction aphasia > poor repetition but good comprehension, lesion in tracts between wernicke and broca
Anomic aphasia > isolation of wernicke area from parietal or temporal areas (fluent but circular speech resulting in poor word finding ability
Expression aphasia > hesitant and distorted speech
Amorphosythesis
inability to recogonize the right side of body, or even to identify simple objects
Multiple sclerosis
Autoimmune disease that results in demyelination of neuron, making them “hard
3 types of memory
Working memory > stored informatino required for the immediate performance of a task. Occurs in frontal cortext
Short term memory
Long term memory
Short term memory
1) Stored from minutes to days
2) Susceptible to brain trauma
3) Requires long-term potentiation to enhance synaptic activity
Long-term potentiation
facilitates transmission of action potentials
1) increase in number of glutamate receptors
2) requires calcium, which bones to glutamate receptors to the protein calmodulin
Calmodulin dependent proten kinase II
Has to do with short-term memory formation somehow.
Long term memory
Requires the prior formation of short-term memory.
Can last years to a lifetime.
More resistant to brain trauma
Consolidation
The process of transferring short term memory to long term memory
A gradual process where new and strong synaptic connection occur
Repeating information and associating it with existing memories or emotion increase consolidation
Strengthened synapses help long term memory form.
cAMP=responsive transcription factor. Important substance for initiate transcription.
Dendritic spines - increase the strength of the synapse
Declarative memory
Explicit memory; retention of facts
What parts of the brain are responsible for declarative memory?
Hippocampus and amygdala
Procedural memory
implicit; reflexive memory. developmenet of skills or procedures
conditioned reflexes, too
Where is procedural memory stored?
cerebellum and premotor area
How are memories stored in the brain?
Memory engram > a network of neurons and their pattern of activity
Connected memories may be stored in different “pigeon holes”
Limbic system - what does it include, and what does it influence?
includes > olfactory cortex, deep cortical regions, various nuclei
influences > emotions, visceral responses to emotions, motivation, mood, long term memory, and pain nd pleasure
Associated with reproduction and getting food and water
Which sense is most associated with the limbic system? Why?
Olfactory
1) reminds us to get food
2) smell detects pheremones, attracting two animals together
Cingulate gyrus
the satisfaction center of the brain; assocated with satisfaction after a meal or sex.
can be impacted by drugs that cause dependence
Gambling, kelptomania an overeating cause neural patterns in the cingulate gyrus that are similar to addiction
Alzheimer disease
decrease in brain size from loss of neurons in cerebral cortex
include memory loss, intellectual deficiency, , short attentions span, moodiness
characterized by amyloid plages and nerofibillary tangles
Cerebrovascual accident
Stroke > death of brain tissue due to disruption of vascular supply
2 types of stroke
Hemorrhagic stroke > bleeding of arteries supplying brain tissue
Ischemic stroke > arties supplying brain tissue are blocked
