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539 Cards in this Set

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What is the ventral boundary of the hypothalamus?
optic chiasm, infundibulum
What is the posterior border of the hypothalamus?
mammillary bodies and midbrain
What is the anterior border of the hypothalamus?
lamina terminalis, preoptic area, septum
What is the superior border of the hypothalamus?
hypothalamic sulcus
What is the lateral border of the hypothalmus?
optic tract
What are the 2 main fxs of the hypothalamus?
integration, coordination
What are the five types of information that the hypothalamus integrates?
visceral, endocrine, homeostatic, cognitive-affective, sensory about environment
What is the main blood supply to the hypothalamus?
posterior cerebral artery
How does the hypothalamus regulate the internal environment?
ANS, endocrine state, motivational state
How does the hypothalamus regulate the external environment?
coordinates behavior that satisfies the motivational state
Visceral afferents to the hypothalamus come from? What nucleus do they synapse in?
CN 9, 10 ganglia (baroreceptors, gut, respiratory system); synapse in nucleus of solitary tract
Endocrine information to the hypothalamus comes from?
hormone levels in the blood, CSF
Homeostatic information to the hypothalamus comes from?
blood glucose, osmolarity, temperature, fat metabolism
Cognitive information to the hypothalamus comes from?
frontal, orbitofrontal, and anterior cingulate cortices, along with the basal forebrain limbic system
Sensory information to the hypothalamus comes from?h
hypothalamic reticular formation and retinal afferents
Because of the tight packing of the hypothalamic nuclei, what can cause damage to them?
closed head injuries, brain surgery, meningitis, encephalitis, strokes, subarachnoid hemorrhages, and neoplasms
What does the preoptic nuclei control?
behaviors necessary for the propagation of the species including a large repertoire of reproductive and maternal behaviors
The development of the preoptic nuclei is under the control of?
estrogen and testosterone during critical periods
Regulation of LH/FSH gonadotropin release from the anterior pituitary is under control of which nuclei?
preoptic nuclei
What did the Simon-LeVay study show?
interstitial nucleus of the anterior hypothalamus well developed in heterosexual men, but not in homosexual men
Which nuclei is important for heat dissipation?
preoptic nuclei
What is the most anterior hypothalamic nuclei?
preoptic nuclei
What is the location of the paraventricular nuclei?
bilaterally adjacent to dorsal third ventricle
What is the afferent to the paraventricular nuclei?
brainstem
What are the 3 efferents from the paraventricular nuclei?
brainstem/spinal cord, median eminence, posterior pituitary
What are the 2 functions of the paraventricluar nuclei?
secretes vasopressin, oxytocin, corticotropin releasing factor; autonomic regulation
Lesions of the paraventricular nuclei lead to?
diabetes insipidus with polyuria and polydipsia
Closed head injuries, stroke, and neoplasms in the paraventricular nuclei result in?
syndrome of inappropriate secretion of ADH (SIADH)
What is the location of the supraoptic nuclei?
bilaterally adjacent to optic chiasm and tracts
What is the afferent to the supraoptic nuclei? The efferent?
brainstem; posterior pituitary
What are the 3 main functions of the supraoptic nuclei?
produce oxytocin and vasopressin; osmosensitivity (water balance and volume regulation); lactation, milk ejection, orgasm, maternal behavior
Lesion in the supraoptic nucleus can lead to? Injuries in this area can lead to?
diabetes insipidus with polydipsia and polyuria; SIADH
What is the location of the suprachiasmatic nuclei?
bilaterally located on midline above optic chiasm
Afferents to the suprachiasmatic nuclei? Efferents?
retinal ganglion cells; output eventually reaches pineal gland via IML cell column and superior cervical ganglion
What is the function of the suprachiasmatic nuclei?
entrains circadian rhythms of sleeping, eating, melatonin synthesis
What is the function of ADH?
water retention by kidney
What is the function of oxytocin?
milk letdown and uterine contraction
What happens in pts with SIADH?
they conserve more water than they are supposed to
What does the pineal gland produce?
melatonin
What is the function of the anterior hypothalamic area?
cooling system for body temperature
Stimulation of the anterior hypothalamic area causes?
panting
What is the location of the arcuate nuclei? Functions?
base of the third ventricle; secretes dopamine, GnRH, GHRH, at the median eminence
What is the location of the ventromedial nuclei?
posterior on either side of the fourth ventricle
Bilateral lesions of the ventromedial nuclei lead to?
overeating and obesity; rage and aggressiveness
What is the location of the lateral hypothalamic area? Functions?
diffuse area bounded by internal capsule and fornix; regulation of sympathetic neurons in spinal and cord, and feeding
What would you lesion bilaterally to abolish feeding behavior?
lateral hypothalamic area
What is the location of the posterior nuclei? Functions?
posterior and dorsal to mammillary bodies; heating system of the body
Stimulation of the posterior nuclei causes?
vasoconstriction, shivering, and increase in body temperature
What is the location of the mammillary nuclei?
most posterior and ventral in hypothalamus
What are the afferents to the mammillary nuclei? Efferents?
hippocampus; anterior thalamic nucleus and midbrain tegmentum
What is the function of the mammillary nuclei? Susceptible to effects of?
memory consolidation; alcoholism or stroke
Necrosis of the mammillary nuclei is noted in what?
Korsakoff's psychosis
One of the well known hypothalamic afferents is the hippocampal-hypothalamic fiber. What does it connect?
hippocampus to mammillary bodies
Another well known hypothalamic afferent is the amygdalohypothalamic fiber. What does it connect?
from the amygdala to anterior nuclear area, preoptic, ventromedial, and arcuate nuclei
What is the third well known hypothalamic fiber?
retinohypothalamic fiber
What is one of the well known hypothalamic efferents?
mammillothalamic tract
What are the two hypothalamic efferents that influence the pituitary gland?
tuberohypophysial tract and hypothalamoneurohypophyseal tract
What is the hypothalamic efferent that regulates autonomic activity?
from lateralposterior and anteromedial hypothalamus to brainstem nuclei and the spinal cord IML cell column at all levels to terminate on ipsilateral preganglionic parasympathetic and sympathetic neurons
Are lateral and posterior hypothalamus SNS or PNS?
SNS
Are anterior and medial hypothalamus SNS or PNS?
PNS
What 7 things are seen with SNS activation?
dilated pupils
piloerection
vasoconstriction
increased HR
increased respiration
decreased gut/bladder motility
rage rx-fight or flight
What 2 things are seen with PNS activation?
decreased HR
increased gut motility
Injury of cervical SNS or descending hypothalamospinal fibers causes?
ipsilateral Horner's syndrome
What 5 things are associated with Horner's syndrome?
Miosis-paralyzed dilator muscle
Ptosis of eyelid-paralyzed levator palpebrae muscle
Enopthalmos-paralyzed orbital muscle
Anhydrosis-absence of sweating
Vasodilation-increased temperature over face/neck
Where does the fornix begin? Where does it end?
hippocampus; mammillary bodies
What is the same as the forebrain?
telencephalon
The forebrain comes from the most ____ part of the neural tube, developing out of the ____?
rostral; prosencephalon
The mesencephalon gives rise to?
midbrain
The rhombencephalon or hindbrain gives rise to?
pons, medulla
The telencephalic vesicles, diencephalon, and optic vesicles make-up the?
forebrain
The two cerebral hemispheres make-up the?
telencephalon
The telencephalon folds over the ____ and fuses? What is formed in the space made by this fusion?
diencephalon; lateral ventricles and the third ventricle
How many layers compose the neocortex?
6
What feature of our cortex makes us human?
the fact that we have 6 neocortical layers
The size of our dendritic arbors relates to?
cognitive ability
In what layer of the cortex are the pyrimidal cells found?
2/3
In what layer of the cortex are the stellate cells found?
4
What layers of the cortex contain glutamatergic (excitatory) neurons?
layers 2-6
What cells in the cortex are the GABAergic (inhibitory) neurons? What layers of the cortex are they found in?
non-stellate cells; layers 1-6
There are ____ types of pyramidal cells that vary according to their ____?
3; axons
What are the three types of pyramidal cells?
associational, commissural, projection
The supra-granular layers contain which 2 types of pyramidal cells?
associational and commissural
The infra-granular layer contains which type of pyramidal cells?
projection
What are associational fibers?
fibers that communicate with cells in the same cerebral hemisphere
What are corticofugal fibers?
projection fibers; their axons travel away from the cortex
Does granular mean a well-developed layer 4?
yes
Which areas of the brain are granular?
primary sensory regions, prefrontal cortex
Which areas of the brain are agranular?
primary motor and premotor regions
Which part of the cortex needs to project long distances?
motor cortex
The olfactory apparatus develops from the?
prosencephalon
Fractures in the cribiform plate can cause?
loss of sense of smell
What sense diminishes with age?
sense of smell
Damage to the fornix causes?
short term memory loss
What is a function of the entorhinal cortex and hippocampus?
memory
What is the main input to the hippocampus? What is it responsible for?
entorhinal cortex; pre-processing of input signals along with memory consolidation and mapping of spatial environment
What is one of the first areas to be affected by Alzheimer's disease?
entorhinal cortex; impaired sense of direction
Lesions to the entorhinal cortex cause?
deficits in short term memory, anterograde amnesia, and deficits in memory consolidation
The ____ remembers where good and bad things happen and knows the location of self and things in space?
hippocampus
White matter tracts are derived from the?
prosencephalon
Association fibers stay within the?
hemisphere
The lateral ventricles are contained within the?
telencephalon
What are 2 examples of commissural fibers?
corpus callosum, anterior commissure
What three components of the basal ganglia come from the telencephalon?
caudate, putamen, globus pallidus
What are three important functions of the basal ganglia?
initiating voluntary movement
suppressing involuntary movement
maintaining proper muscle tone
What 2 nuclei degenerate with Alzheimer's disease?
medial septal nucleus, basal nucleus of Meynert
Why are the medial septal nucelus and basal nucleus of Meynert important?
the resident magnocellular choline acetyltransferase containing cells supply the entirety of the diffuse cholinergic input to the cerebral cortex
Drugs that increase acetylcholine might be able to help with?
memory loss
What neurons degenerate in Alzheimer's disease? Where does it start?
cholinergic; starts in frontal and temporal lobes
____ input from the VTA modulates the activity of neurons within the ____.
dopaminergic; nucleus accumbens
What is the reward center of the brain?
nucleus accumbens and septal nuclei
Almost every drug in abused by humans has been shown to increase ____ levels in the ____.
dopamine; nucleus accumbens
Depletion of dopamine doesn't reduce pleasure, but increases?
cravings
Cocaine acts on the?
nucleus accumbens
Meth acts on the?
nucleus accumbens and the dopamine neurons of the VTA
Heroin and nicotine act on the?
dopamine neurons of the VTA
What part of the brain is involved with the regulation of emotions induced by music?
nucleus accumbens
What structure in the brain is considered the basal forebrain?
amygdala
What is the function of the amygdala?
responsible for keeping us aware of possible danger in the world and regulating appropriate responses to it
What acts as the interface between the cortex, hypothalamus, and brain stem?
amygdala
Lesions in the amygdala don't interfere with the sense of?
smell
An intact ____ is needed for emotional responses.
hypothalamus
The part of the cortex that forms a rim around the corpus callosum is termed?
the limbic lobe
What is the Cannon-Bard theory?
cortex generates ANS response that then causes an emotional response
What is the James-Lange theory?
stimulus received and then the ANS stimulated
Lesioning the dorsal medial nucleus in the frontal lobe would cause?
complacent, docile behavior
What area of the brain remembers where good and bad things happen?
hippocampus
What are the 6 main limbic functions?
processing of olfactory information
Prefrontal, orbitofrontal, and anterior cingulate cortices oversee?
when and where to release survival related behaviors - our needs for nutrition, hydration, reproduction, affiliation, fear, anger, and aggression
Hypothalamus, septal nuclei, medial and basolateral amygdala initiate?
neurons directly in charge of survival related behaviors and emotions - initiate sexual reproduction, affiliation, fight, flight, and foraging
Hypothalamic and brain stem autonomic nuclei are associated with?
neurons that directly initiate the optimal sympathetic and parasympathetic physiological environments associated with each activity
Parahippocampal gyrus and uncus, amygdala, entorhinal cortex are the relay for?
conscious and unconscious perception of olfactory stimuli
Dorsomedial thalamus and orbitofrontal cortex are involved with?
conscious perception of smell
Amygdala, mesiotemporal cortex,and the bed nucleus of the stria terminalis are involved with?
associational learning
Hippocampus and mesiotemporal lobe involved with?
contextual memory, short term memory, and memory consolidation
What does the HOME component of the limbic system mean?
Homeostasis
Olfaction
Memory
Emotions
Lesions in the orbitofrontal cortex reduce?
aggression and emotional responsiveness
Stimulation of the orbitofrontal cortex causes?
increased plasma cortisol
increased EEG arousal
Cutting the dorsal medial thalamus's connection to the orbitofrontal lobe leads to?
docileness and flat affect
What are the 5 components of the Papez circut?
hippocampus
mammillary bodies
anterior thalamic nuclei
cingulate gyrus
hippocampus
What is an important connection for emotional expression?
dorsomedial thalamus to the frontal lobe
What part of the brain develops until the age of 25?
prefrontal cortex
What 3 main things is the prefrontal cortex involved with?
executive control of emotional responses
weighs consequences of actions
seat of personality and self reflection
People with obsessive-compulsive disorder have greater activity in?
cingulate gyrus
Stimulation of the cingulate gyrus causes?
arrest reaction - inhibition of respiratory movements (ANS); enhanced attentiveness, stops other activities
What is the pleasure center of the brain?
septal area
What part of the brain processes fear?
amygdala
What part of the brain integrates sensory cortical and sensory thalamus information and makes a decision about which emotion to have about an external stimulus?
amygdala
What is "stress?"
what we feel when are fear system is activated
What is perception?
the form of the sensory information arriving to the amygdala which underlies the vulnerability to stress
What part of the brain is shaped like an almond?
amygdala
What is the most common mental health problem in the U.S.?
anxiety disorders
Anxiety disorders have a high comorbidity with?
depression and other "psychosomatic" illnesses
Which nuclei of the amygdala are the most important for the fear circuitry?
lateral, basolateral, and central nuclei
Early developmental exposure to stress in humans can?
alter brain development and later response to stress
There are two pathways by which sensory input reaches the amygdala. What is the low road? What is the high road?
Low road - through the sensory thalamus
High road - through the sensory cortex
Which road to the amygdala is the unconscious route?
low road
Undue, chronic activity in what path to the amygdala may underlie anxiety disorders?
low road
What are the main points about the low road?
through sensory thalamus
short latency
degraded information
starts fear/stress autonomic responses
What are the main points about the high road?
through the sensory cortex
long latency
high resolution information
may confirm or refute initial impression of the low road pathway
Sympathetic outputs of the amygdala are from the central nucleus to the?
lateral hypothalamus
Parasympathetic outputs of the amygdala are from the central nucleus to the?
DMN of the vagus
Freezing causes information from the central nucleus of the amygdala to travel to the?
central grey
The startle reflex causes information to travel from the central nucleus to the?
reticularis caudalis (reticulospinal tracts)
Information from the central nucleus of the thalamus to the PVN causes the release of?
CRF and stress hormones
What are the stress hormones?
epinephrine, norepinephrine, cortisol
The body's acute response to the stress hormones is?
to optimize the body for the fight or flight response
Are all major organs involved in the stress response?
yes
What causes cortisol release?
anterior pituitary ACTH-induced release from adrenal cortex
What 4 things does cortisol do?
stimulation of gluconeogenesis in liver; mobilization of extrahepatic AAs; inhibition of glucose uptake in muscle and adipose tissue; stimulation of fat breakdown in adipose tissue
What causes epi and norepi release? Where is it released from?
sympathetic stimulation of release from adrenal medulla
Epi and norepi cause what 7 things?
increased rate and force of heart muscle contraction
constriction of blood vessels
dilation of bronchioles
stimulation of lipolysis
increased metabolic rate
dilation of pupils
GI tract inhibition
Anatomical and functional changes in the ____ are associated with anxiety and other affective disorders. Some examples are?
amygdala; bipolar disorder, depression, autism
Face recognition is a specialty of the?
amygdala
What is Urbach-Wiethe Syndrome?
genetically based lipid storage disease that destroys the amygdala; these people have difficulty judging emotions from facial expressions
What part of the brain can exert a calming influence on the amygdala?
prefrontal cortex
What type of models have provided information about anxiety which is already used clinically?
animal
What type of signals does the prefrontal cortex send to the amygdala?
sends "all clear" signals when the stimulus or situation is no longer a danger; termed extinction
What are the types of treatment for anxiety disorders?
cognitive behavior therapy and medications
What types of meds can be used in treating anxiety disorders?
serotonin, GABA, norepinephrine, glutamate
What causes Kluver-Buch syndrome?
bilateral ablation of the amygdala and other temporal lobe structures in animals and man - bilateral temporal lobectomy
What was bilateral temporal lobectomy once used for?
treatment/control of seizures
What is a hallmark sign of Kluver-Buch syndrome?
psychic blindness
What is psychic blindness? Why do patients do this?
compulsion to examine every object tactilely, orally, and visually; along with a compulsion to ingest non-food items; pt is trying to extract information about the stimulus because the amygdala is no longer there to do the job
What are some other characteristics of Kluver-Buch syndrome?
fearlessness, tameness, and hypersexuality
With what area of the brain did Olds and Milner perfrom their famous experiment? What was the experiment?
septal area; electrical self-stimulation by a rat
What are the 5 primary functions of the limbic system?
processing of olfactory information; control of drive-related behavior; control of emotional behavior; substrate for learning and memory; control of autonomic activity
What tract gets things from the mammillary bodies to the thalamus?
mammillothalamic tract
What structure separates the thalamus from the hypothalamus?
third ventricle
What is the output of the hippocampus?
fornix
What structure in the brain is located in the medial temporal lobe?
hippocampus
What white fiber tract connects the R temporal lobe to the L temporal lobe?
anterior commissure
What is learning?
acquisition of new information
What is memory?
retention or storage of the new information that is acquired
What are the 2 types of memory?
declarative and procedural
Does the loss of one memory system impair the other one?
no
What are declarative memories?
facts and events that can be recalled and declared; example would be your birthdate
What structures must be intact to form declarative memories?
limbic structures - medial temporal lobe and the medial diencephalon
What pathway comprises the medial temporal lobe?
hippocampus through the fornix to the hypothalamus
What pathway comprises the medial diencephalon?
mammillary bodies through the mammillothalamic tract to the thalamus; anterior nucleus
What are procedural memories?
motor skills, habits, and reflexes modified by experience; example would be how to land a plane
Which memories aren't available to conscious awareness?
procedural
What brain structures must be intact for procedural memories?
basal ganglia and cerebellum
Memory ____ over time.
changes
What is immediate memory?
the sensory register; seconds in duration
What is the capacity of immediate memory?
very large
What must be done with immediate memories?
must be converted into a more stable form or will be RAPIDLY lost with newer incoming sensations
What is the length of short term memory? The capacity?
seconds to minutes duration; very limited (7 +/- 2 pieces of information)
What does short term memory require?
requires constant attention; must be consolidated into long term memory or memories in short term will be lost as soon as attention shifts
What is the duration of long term memory? The capacity?
very long duration; vast capacity
Long term memories are very resistant to?
forgetting
What process forms long term memories?
consolidation
Memories in the process of consolidation are vulnerable to?
variety of insults; for example head trauma, seizures, electroconvulsive shock
How would you test long term memory in a pt if they had suffered an insult?
using a family member to verify the pt's recall or have the pt identify famous faces
What are the types of amnesia?
retrograde and anterograde
The phenomenon of ____ is a normal process.
forgetting
The phenomenon of ____ is the pathological loss of memories.
amnesia
What is retrograde amnesia?
loss of accumulated long term memories due to damage to areas of the brain where long term memories have been stored
Where are memories stored in the brain?
in the cerebral cortex at the end of their processing pathway
What is anterograde amnesia?
inability to form new memories as a result of damage to areas of the brain involved with consolidation of memories
What pathway consolidates memories?
hippocampus>hypothalamus>
thalamus
What areas of the brain consolidate memories?
medial temporal lobe and medial diencephalon
What part of the brain "talks to itself?"
cortex
The high level sensory/association cortices are thought to be the location of?
immediate and long term memory
Lesions in what area of the brain would result in the inability to identify or remember familiar faces?
inferior temporal cortex
If a pt has prosopagnosia, what can they recognize about an individual?
features of a face, shape, depth, movement; can also recognize the person by gait, voice, clothing, and movement
What lobe of the brain has neurons that can identify faces?
temporal lobe
The magnocellular pathway identifies?
motion
The parvocellular pathway identifies?
what it is
What is the "top-down" method for identifying something?
using the voice, scent, motion to identify
What is the "bottom-up" method for identifying something?
processing with the eyes and going from there
How does consolidation occur?
by strengthening synaptic connections between neurons in multiple neocortical areas
Consolidation of memory requires an intact set of?
limbic structures
Are limbic structures involved in the long term storage of memories or the consolidation of declarative memories?
only in the consolidation of declarative memories
What is the number one site for epileptic seizures?
temporal lobe
Bilateral lesions in what 2 main areas of the brain cause global, anterograde amnesia?
medial temporal lobe and medial diencephalon
What is the important brain structure in the medial temporal lobe?
hippocampus
What are the important brain structures in the medial diencephalon?
mammillary bodies and anterior nucleus of the thalamus
What are CA3 and CA1?
layers of cortex with pyramidal cells
Is CA1 or CA3 very sensitive to anoxia and ischemic insult?
CA1
What is the input to the hippocampus?
entorhinal cortex
What is the output of the hippocampus? What is the output tract?
mammillary bodies and hypothalamus; fornix
From the input starting at the entorhinal cortex, what four components come next?
dentate gyrus > CA3 > C1 >subiculum
The consolidation of memory is ____ and ____.
gradual and cumulative
How long does the process of consolidation take?
takes place over hours and days
In short, what is long term potentiation?
process of strengthening the synapses
The physiological basis of memory is thought to result from the ____ or ____ of synapses through an ____ dependent process.
strengthening; potentiation; activity
What synapses are strengthened during potentiation?
cortico-cortical association pathways (pyramidal cells)
What dislodges Mg++ from the channel so that Ca++ can enter the cell?
EPSP
What is released from the CA3 axon onto the CA1 pyramidal cell spine?
glutamate
With sufficient activity at the synapse, which receptor will depolarize the postsynaptic membrane?
non-NMDA
What happens when the postsynaptic membrane is depolarized?
EPSP
Does glutamate enter the postsynaptic cell?
no, it just binds to the channel and opens it so that Na+ can enter
What happens when Ca++ enters the cell?
it stimulates calcium dependent enzymes
What do the calcium stimulated enzymes do?
increase the sensitivity of the postsynaptic neuron to glutamate
Long lasting change in the sensitivity of the synapse is thought to occur by?
a signal sent to the nucleus that stimulates the production of proteins (glutamate receptors, cytoskeletal proteins, neurotrophic factors)
When you say that the pyramidal cells' spines grow, what does that mean?
the spine increases its surface area and therefore the availability of receptors
What happens to the release of glutamate during a seizure?
abnormal amounts are released which leads to excitotoxicity
What helps with memory retrieval?
stimulus feature reactivates one of the cortical areas where one of the aspects of memory is stored
What does it mean when you say that memory recall is variable?
attempts to recall a memory may not succeed in reactivating all areas of where the memory is stored
What does it mean when you say that memory recall is sometimes incorrect?
attempt to recall a memory may lead to activation of inappropriate areas of the cortex
Which is easier...recognition or recall?
recognition is easier than recall
What does recall require?
self-generated stimulus for the reactivation of the corical areas where the memory is stored
R visual cortex receives information from?
L visual fields
A lesion in the R visual cortex would result in?
contralateral hemianopsia
What Broadman's area is V1?
BA 17
What makes up 75% of the neocortical tissue?
association cortex
Our highest brain function is?
cognition
What are the 3 main association areas of the brain?
prefrontal, parietal, temporal
What neurons are located in the prefrontal cortex?
delay-specific neurons and mirror neurons
What is the function of delay-neurons and mirror neurons?
planning behavior, setting goals, recognizing behaviors
What neurons are located in the parietal lobe?
attention-specific neurons
What is the function of attention-specific neurons?
attending to complex stimuli
What neurons are found in the temporal lobe?
recognition-specific neurons
What is the function of recognition-specific neurons?
recognizing and identifying objects
What is the main function of the association cortices?
these regions are responsible for the information processing that goes on between sensory input and motor output
What layers of the cerebral cortex allow the cortex to talk to itself?
layers 2 and 3
What does the cerebral cortex talk through?
corpus callosum
What is the relay station of the brain?
thalamus
All information relayed through the thalamus travels to the? Which layer?
cortex; layer 4
What layer of the cortex is the output to the thalamus?
layer 6
What layer is precentral gyrus - motor?
layer 5
What is found in VA/VL?
motor; basal ganglia
What is VPL? Where are its cell bodies
contralateral body sensation; nucleus cuneatus and nucleus gracilis
What is VPM? What layer of the cortex does it send information to?
contralateral face sensation; layer 4
What is the tract for the hippocampus? The relay nuclei? The area of the cortex? Modality?
fornix; anterior nucleus; cingulate gyrus posterior; memory
What is the tract for the amygdala and olfactory cortex? Modality? Relay nuclei? Area of the cortex?
stria terminalis; emotions; medial dorsal nucleus; prefrontal cortex and cingulate cortex anterior
What is the relay station for your emotions?
medial dorsal nucleus
What is the ascending reticular activating system important for?
arousal
What activates the entire cortex?
activated brainstem reticular formation
What is the "gate-keeper" of the thalamus?
reticular nucleus in the thalamus
What is the reticular nucleus of the thalamus? What is the location?
thin sheet of neurons just lateral to the rest of the thalamus and medial to the internal capsule
What is the only nuclei in the thalamus that DOESN'T project to the thalamus? Where does it project to?
reticular nucleus; projects to itself
Where does the reticular nucleus of the thalamus get its input from?
cortex, thalamus, ascending reticular activating system, and forebrain
What kind of neurons are found in the reticular nucleus of the thalamus?
pure inhibitory GABAergic neurons
What is the cingulate gyrus associated with?
memory
What is the prefrontal cortex associated with?
emotion and cognition
What is cognition?
our ability to know our world by attending and planning responses to internal motivation and external demands
Which cortices are responsible for planning appropriate behavior responses?
frontal association cortices
Which cortices is responsible for attending to complex stimuli in the external and internal environment?
parietal association cortices
Which cortices are responsible for indentifying the stimuli?
temporal cortex
The path that travels from V1 to the parietal lobe determines?
motion; where the object is
The path that travels from V1 to the temporal lobe determines?
what the object is
Which cortex is dominant?
neither one; they work together - complementary specialization
What hemisphere is specialized for sequential and analytical processes?
categorical hemisphere; in most people it is the left
What hemisphere is specialized for visuospatial relations?
representational hemisphere; right
Whether you are R or L handed, your categorical hemisphere is?
most likely the left
Which hemisphere is for language?
left
What does the L hemisphere specialize in?
intellectual, rational, verbal, analytical thinking, and declarative memory; concerned with categorization and symbolization
Lesions in the L hemisphere cause?
language disorders
Are pts that have lesions in their L hemisphere aware of their disability?
yes, and are often depressed
What does the R hemisphere specialize in?
perceiving, and in emotional, nonverbal, and intuitive thinking, along with procedural memory
Which hemisphere is involved with recognition of objects by their form and the recognition of musical themes?
right
Lesions in the R hemisphere produce?
agnosias
What is agnosia?
inability to recognize objects by a particular sensory modality even though the sensory modality is intact
Where are the lesions normally found in the R hemisphere?
temporal and parietal lobes
What region is responsible for attention?
inferior parietal lobe
Are pts aware of their lesion if it is on the right?
no; pts are unaware and may even be euphoric
Are pts with lesions on the right able to recognize emotions in other individuals?
no
What are the main jobs of the prefrontal cortex?
cognitive behavior, motor planning, and maintenance of an individual's personality
What part of the brain weighs consequences of actions being considered?
prefrontal cortex
What part of the brain carries out motor tasks involving memory or in relation to sensory inputs?
prefrontal cortex
Where would a lesion be that would cause change in a pt's character?
prefrontal cortex
Lesions in the frontal lobe are diverse and devastating if?
they are bilateral
How does a pt with a frontal lobe lesion present sometimes?
boastful of physical prowness, little restraint in conversation, and unable to plan for the future
Where and on what side of the brain is Broca's area located?
inferior frontal gyrus; left hemisphere
What is Broca's aphasia?
difficulty in expressing thoughts either in written or in spoken languge
What are other names for Broca's aphasia?
nonfluent, expressive, or motor aphasia
What Broadman's areas are Broca's area?
44, 45
What is the blood supply to Broca's area?
superior MCA
What can also be seen in Broca's aphasia pts?
contralateral UE paralysis
What Broadman's area is Wernicke's area?
22
What is the blood supply to Wernicke's area?
inferior MCA
What is the function of the parietal-temporal association cortex?
higher sensory function and language
Lesions of the left parietal-temporal lobe produce?
aphasias
What is aphasia?
disorder of language
Where is the lesion that causes Wernicke's aphasia?
posterior part of the superior temporal lobe
Fluent aphasia is the same thing as?
Wernicke's aphasia
What is Wernicke's aphasia?
difficulty in comprehending speech and in reading
A lesion in the auditory cortex causes?
conduction aphasia
What is conduction aphasia?
patient has no trouble speaking or hearing, but has trouble putting words together or conjuring up words
Damage to the angular gyrus causes?
anomic aphasia
What is anomic aphasia?
inability to name objects
What is global aphasia?
loss of all language skills
Lesions of the left or right parietal-temporal lobes produce?
agnosia
What is agnosia?
"not knowing;" inability to recognize a complex sensory stimulus such as an object even though sensory pathways and perception of the object are intact
What is astereognosis?
inability to recognize the form of objects by touch alone
What is prosopagnosia? What causes it?
inability to recognize old faces or remember new faces; there are no visual pathway deficits; unilateral or bilateral temporal lobe damage
What causes Gerstmann's syndrome?
parietal lobe lesion
What are the 4 signs of Gerstmann's syndrome?
confusion between R and L sides, difficulty in saying which finger was touched, dysgraphia, dyscalculia
Lesions that aren't well localized cause?
apraxia
What is apraxia?
inability to perform an action in response to a verbal command in the absence of any deficit in comprehension, incoordination, or motor weakness
Lesions of the right parietal lobe produce?
inability to appreciate emotional aspects of a verbal message conveyed by tone, loudness, or timing; if inferior parietal lobe affected pt also can't express emotion in speech
Where is the lesion that causes Contralateral Neglect syndrome?
right parietal lobe
What is Contralateral Neglect syndrome?
tendency to neglect the opposite (usually left) side of the body
The left hemisphere attends to which half of the body?
only the right half
A lesion of the left parietal lobe is compensated by?
the right hemisphere
The right hemisphere attends to which side of the body?
the left and right side of the body
What happens to the body when the right hemisphere is damaged?
there is no control for the left side of the body and it is neglected
What is hemiasomatognosia?
neglect of one side of the body
How do you test for Contralateral Neglect syndrome?
ask pt to draw; drawing lacks left side of picture
What do you not see with Contralateral Neglect syndrome?
the environment or the body on the left side
What is on the X axis of an EEG?
time in seconds
What is on the Y axis of an EEG?
voltage
What is the #2 neurological disease?
epilepsy
What does an EEG measure?
detects current; extracellular field potentials; NOT APs
What does EEG stand for?
electroencephalogram
What does an EEG measure collectively?
electrical activity of the neurons in the cortex
What can cause the activity of the cortical neurons to change?
behavioral states and pathologies such as coma and epilepsy
The activity of the EEG reflects?
cortical neurons post-synaptic potentials
What state shows low amplitude and high frequency?
excited
What state shows high amplitude and low frequency?
relaxed
What state has lowest frequency and highest voltage?
stage 4 non-REM sleep
What term should be used in place of "deep sleep?"
stage 4 non-REM sleep
Lots of negative charges cause the spike on an EEG to?
go up
Lots of positive charges cause the spike on an EEG to?
go down
What does the thalamus do when you are sleeping?
sends rhythmic signals to the cortex
What cells are the principal source of EEG potentials? How are these cells orientated to the surface of the brain?
pyramidal cells; perpendicular
EEG is the result of?
extracellular current flow associated with the summated synaptic potentials in activated pyramidal cells
When cortical neurons fire synchronously, what happens to their biopotentials? Their amplitude? Their frequency?
biopotentials summate; large amplitude (high voltage); slow rate (low frequency)
When cortical neurons fire asynchronously, what happens to their biopotentials? Their amplitide? Their frequency?
biopotentials summate; small amplitude (low voltage); fast rate (high frequency)
How many cps with beta waves? When do they occur?
>13; active, awake, thinking, eyes open, REM sleep
How many cps with alpha waves? When do they occur?
8-13; relaxed, mental inactivity, eyes closed
What waves have the highest amplitude over the occipital, posterior region of the head?
alpha; you aren't seeing anything since your eyes are closed
What waves are uncommon? How many cps? When do they occur?
theta; 4-8; awake youth, small amount in awake adult, drowsiness, and non-REM sleep states
How many cps with delta waves? When do they occur?
<4; non-REM sleep states
EEG is a record of ____ plotted against ____.
voltage; time
Voltage of the EEG is what determines the?
amplitude
EEG voltage is attenuated by?
meninges, CSF, dura, bone, and scalp
How many electrodes are used in full standard placement?
21
Odd numbered electrodes are placed on what side of the head? Even numbered electrodes are placed on what side of the head?
left; right
Summation of synchronously firing neurons will generate the ____ frequency and ____ amplitude EEG waves. What waves are an example of this?
slowest; highest; delta
Summation of asynchronously firing neurons will generate
____ amplitude waves with ____ frequency. What waves are an example of this?
low; high; beta
What waves are pronounced over the occipital cortex in awake, relaxed humans with their eyes closed?
alpha
What 2 things can rapidly change EEG patterns?
eye opening or mental calculations
Alerting the subject by making them open their eyes blocks what waves? What waves are produced after the subject opens their eyes?
alpha; beta
What is one method clinically used to enhance existing EEG abnormalities or induce abnormal EEG patterns?
hyperventilation; 20 breaths/minute (deep breathing for 2-4 minutes)
What does hyperventilation do to the the partial pressure of CO2 in the lungs, blood, and brain?
decreases
What is the partial pressure of CO2 in the brain normally?
40 torr (mmHg)
Hyperventilation causes respiratory acidosis or alkalosis?
alkalosis (decreased H+ conc.)
What will hyperventilation do in a normal subject?
will provoke the slowing of waves; seen in children
What will hyperventilation provoke in an abnormal subject?
generalized synchronous seizure discharge or petit mall seizure
What is another method used to clinically enhance EEG abnormalities or induce abnormal EEG patterns?
intermittent photic stimulation - flashing light of 1-30 cps
What is the physiologic response to intermittent photic stimulation? What will it cause?
photic driving of the occipital EEG; rhythmic EEG activity with the same frequency as flashing light
What is the response to intermittent photic stimulation in a patient with epilepsy?
photoconvulsive response occurs at 15cps
What are some less commonly used methods to clincally enhance EEG abnormalities or induce abnormal EEG patterns?
visual pattern stimulation
auditory stimulation
somatosensory stimulation
convulsants
eye and limb movements
hypoglycemia
sleep deprivation
What is seizure activity?
abnormal neuron discharge
What can seizure activity be due to?
trauma, low oxygen, tumors, infections, high body temperatures, toxic states, and unknown in 50% cases
What % of the population suffers from epilepsy?
0.5-1%
What form of seizure begins in a restricted brain region and remains local or spreads to adjacent cortex?
partial or focal epilepsy
Does pt remain conscious during a partial or focal epileptic seizure?
yes
For a partial or focal epileptic seizure, where are EEG spikes seen?
only in a FEW EEG channels
What is Jacksonian motor seizure an example of?
partial or focal epileptic seizure
What is the form of seizure that involves large parts of the brain right from the start of the seizure?
generalized or non-focal epilepsy
Is pt conscious during a generalized or non-focal epileptic seizure?
no
Where are EEG spikes seen in a pt with generalized or non-focal epilepsy?
activity is evident on all EEG channels at the same time
What are the 2 types of generalized or non-focal epileptic seizures?
absence (petit mal) and grand mal
If pt is having a absence seizure, do they fall?
no
If pt is having a grand mal seizure, do they fall?
yes
What seizure shows a 3Hz spike and wave pattern?
absence seizure
What occurs during a grand mal seizure?
pt falls; pt has alternating periods of tonic and clonic body movements
What is the post-ictal state?
state of pt after seizure; they won't remember anything about their seizure
What is tonic movement? What is firing?
periods of increased muscle tone; "AL"
What is clonic movement?
periods of jerky movements
Overly rapid elevation of plasma Na+ conc. may cause neurologic symptoms in a pt with chronic hyponatremia because?
they lose fluid too quickly and their brain cells shrink too rapidly
What occurs in the vegetative state?
cortex is dead; brainstem is okay; pt NOT in coma; pt NOT
"locked in"
What is a classic example of the sleep-wake cycle? What are some other examples?
circadian biological rhythm; body temperature, endocrine secretion
Is the sleep-wake cycle dependent on the visual system or zeitgebers?
no
What are zeitgebers? What are some examples?
time cues; light/dark cycle of Earth, alarm clocks, meal times, etc
Without the normal zeitgebers the human sleep-wake will increase to?
26 hrs
The anterior commisure fibers go from?
temporal lobe to temporal lobe
The mammillary bodies connect to?
anterior nucleus of the thalamus
What 2 things does the paraventricular nucleus and the supraoptic nucleus secrete?
ADH and oxytocin
What nucleus may entrain the sleep/wake cycle to the external environment?
suprachiasmatic nucleus of the hypothalamus
Which organs don't have a BBB? What is one of their functions?
subfornical organ; works as an osmoreceptor
Hypernatremia causes the subfornical organ to?
fire an AP which causes release of ADH
Hyponatremia causes the subfornical organ to?
not fire an AP and therefore no release of ADH
What is the pigment used to detect luminance?
melanopsin
What is melatonin synthesized from? When is it released? From where?
serotonin; in the dark; pineal gland into the blood
What is the pathway from the suprachiasmatic nucleus to the pineal gland?
Suprachiasmatic nucleus
IML T1-T2 of spinal cord
Superior cervical ganglion
Pineal gland
When are our two major sleep gates?
one during evening; one during mid-afternoon
What are the 3 states of consciousness for the brain?
wake, REM, non-REM
What are the 3 ways to measure states of consciousness?
EEG, EMG, EOG
For wake state of consciousness, what do you see for EEG, EMG, and EOG?
EEG-beta; EMG-high; EOG-some fast eye movements
For the Non-REM state of consciousness, what do you see for EEG, EMG, and EOG?
EEG-delta; EMG-low; EOG-fast eye movements are absent
For the REM state of consciousness, what do you see for EEG, EMG, and EOG?
EEG-beta; EMG-absent, "AL" paralyzed; EOG-fast eye movements are present
What muscles aren't paralyzed during REM sleep?
extraocular muscle (3,4,6) and diaphram
The awake state is characterized by? What waves are associated with this state?
a wide range of reactivity from terror through drowsy; beta
Who identified REM sleep and when?
Drs. Aserinsky and Kleitman; 1953
What 3 things is REM sleep identification based on?
low or absent muscle tone, bursts of rapid eye movement, and brain waves similar to beta waves
What are 2 other names for REM sleep?
paradoxical sleep or desynchronized sleep
80% of people woken up during REM sleep report?
vivid, active dreams
What is paralyzed during REM sleep? What is activated?
all muscles except for extraocular muscle and diaphram; brain
Is afferent sensory input inhibited during REM?
yes
Phasic REM encompasses?
abrupt changes in respiration, BP, and HR as well as whole body twitches and jerks in association with bursts of rapid eye movement
How many REM sleep periods per night? How much of total sleep time per night?
4 or 5; about 20%
How long does each REM period last?
about 20 minutes
The first REM period of the night is ____? Each successive REM period?
shortest; becomes longer than the previous one
What causes you to go from wake directly into REM sleep?
a pathological condition
What is the rhythm during which REM and non-REM alternate with each other?
ultradian (<24hr) rhythm of 90-100 minutes
During early or late sleep do you see stage 4 non-REM?
early
High REM sleep state means more stage ____ and ____ non-REM sleep.
2 and 3
All pyramidal cells have same extracellular field potentials during what type of sleep?
non-REM sleep
Non-REM sleep goes by what 2 other names?
slow wave sleep; synchronized sleep
How many stages of non-REM sleep?
4
What happens during Stage 1 non-REM sleep?
brief transition phase, drowsy state, low voltage with mixed frequencies
What happens during Stage 2 non-REM sleep?
signs of spindles and K complexes in the EEG
What do spindles on an EEG mean?
pt having longer non-REM period with less chance of wake period
What happens during stage 3 non-REM sleep?
20-50% of EEG has delta waves
What happens during stage 4 non-REM sleep?
50% of EEG has delta waves
The early portion of nightly sleep is composed of?
delta sleep stages 3 and 4 non-REM
What stages are seen less in the latter part of the night?
stage 3 and 4 non-REM
Persons woken up in non-REM sleep report?
mental activity but no vivid dream reports
Slow rolling eye movements may be present in?
any stage of non-REM sleep
What happens to skeletal muscle and muscle tone during non-REM sleep?
skeletal muscle are not paralyzed, but muscle tone is much less than in the awake state
What stages of non-REM sleep are difficult to wake from? What do you see with adults and children?
3 and 4; adults are not alert and children are very confused
What is somnambulism?
sleepwalking
What is enuresis?
bed-wetting
What is pavor nocturnus?
night terrors
In children, during what sleep state are night terrors, sleepwalking, bed-wetting seen?
non-REM sleep
When do the parasomnias seen during non-REM sleep in children disappear?
puberty
The older you get, the ____ amount of time you sleep?
less
How many hrs a day do infants sleep? What % of time is spent in REM sleep?
16; 50%
How many hrs do adults sleep? What % of time is spent in REM sleep?
8; 20%
What stage of sleep falls slowly and disappears all together in old age?
stage 4 non-REM
What type of process is sleep? What intact structures does it require?
active; brainstem and hypothalamus
What was identified in the upper brainstem-diencephalic junction to be critical for the maintenance of consciousness?
ascending reticular activating system
Lesions in the ascending reticular activating system produce?
coma
What is the ascending reticular activating system (ARAS)?
series of multiple interconnected systems regulated by the pontomesencephalic reticular formation system with wide spread projection systems to the entire nervous system
What is the cortex "alert" system?
intralaminar nucleus of the thalamus
What neurotransmitter is high during wake and REM?
Ach
What neurotransmitter is low during non-REM?
Ach
During what state of consciousness is seratonin highest?
wake
During what state of consciousness is seratonin lowest?
REM
During what state of consciousness is norepinephrine highest?
wake
During what state of consciousness is norepinephrine lowest?
REM
What is the main function of sleep?
really unknown, but most believe it is to maintain the CNS and PNS
What is the classic sleep experiment?
remove an item and see what happens
What nucleus produces seratonin?
raphe nucleus
What nucleus produces Ach?
nucleus basilis of Meynert
What nucleus produces norepinephrine?
locus ceruleus
What where the physical symptoms of total sleep deprivation?
progressive malfunction of the mind and nervous system
What does total sleep deprivation cause?
difficulty concentrating, irritable, decreased motor skill performance
What does recovery sleep after total sleep deprivation show?
rebound in non-REM stage 3 and 4 (this would come first instead of stage 1 and then 2 and so on)
What happened to rats deprived of REM sleep?
die after 30-40 days
What does recovery sleep after REM sleep deprivation show?
REM sleep rebound which makes up the previous REM sleep loss
What does REM rebound sleep show?
decrease in REM sleep latency and increase in REM sleep period duration
What is narcolepsy a disorder of? What do pts have trouble doing?
REM sleep; staying awake during the day
What are sleep attacks?
seen in narcoleptic pts and last for 5-30 minutes
What do narcoleptic dogs lack?
hypocretins-orexins, which are peptides in the hypothalamus that project to the reticular formation
Narcoleptics have a very short?
REM latency; you seen sleep onset REM in these pts where they go from wake directly into REM
Do narcoleptic pts have disrupted night sleep?
yes, but they sleep no longer than normal
What is cataplexy, and who is subject to it?
transient muscular paralysis immediately following sudden emotion; narcoleptic patients
What happens during cataplexy? What can the episode develop into?
pt is conscious but can't move; may develop into REM sleep wiht sleep onset hallucinations
What is sleep paralysis, and who is subject to it?
transient muscular paralysis while drifting into and out of sleep; pt is conscious but can't move; narcoleptic patients
Are narcoleptic patients subject to hallucinations?
yes
What are hypnagogic hallucinations?
hallucinations at the start of sleep
What are hypnopompic hallucinations?
hallucinations at the end of sleep
What is insomnia?
disorder of initiating and maintaining sleep (DIMS)
What is the disorder in which pts have trouble falling asleep (increased non-REM latency)?
insomnia
In a normal person how long does it take to fall asleep? Narcoleptic person? Insomniac?
15-20 mins; 2-3 mins; 1-3hrs
What are some causes of insomnia?
psychiatric disorders, drugs, alcohol, respiratory impairment
What causes CO2 levels in the body to rise?
decreased ventilation
What is sleep apnea?
pathological absence of breathing movements during sleep; pts may have as many as 600+ episodes of respiratory arrest during sleep
What happens to pts with sleep apnea during the day?
they get sleepy
What is the most common form of sleep apnea?
obstructive - airway obstructed in spite of huge swings in intrapleural (esophageal pressure)
What is central sleep apnea?
airway is okay, no swing in esophageal pressure seen; respiratory centers in medulla stop firing
What is mixed sleep apnea?
central sleep apnea that develops into an obstructive apnea
What are some ways to treat sleep apnea?
weight reduction, surgery, CPAP
What is REM sleep behavior disorder? What type of pts is this disorder seen in?
excessive movements during REM sleep; pathological absence of muscle atonia during REM sleep; elderly males
In what stage of sleep does sleepwalking occur?
non-REM
Physiologic parameters during REM are ____ in magnitude between wake and non-REM sleep?
intermediate
What stage of sleep has the lowest physiologic parameters? The highest?
non-REM sleep; REM sleep
What type of capillaries are seen in circumventricular organs?
fenestrated
What is interupted in circumventricular organs?
blood brain barrier
What are tanycytes?
cells that allow the BBB to communicate with the circumventricular organs
What is the only paired circumventricular organ?
area postrema
Where is the area postrema located? What is its fx?
medulla; also called the chemotactic trigger zone; detects toxins in the blood to trigger vomiting
What 3 circumventricular organs fx as osmoreceptors?
subfornical organ, organum vasculosum, lamina terminalis
If plasma osmolarity rises, what happens to cells?
they shrink