Brain anatomy Flashcards
medulla location and function
between the spinal cord and brain, influences flow of information, coordinates swallowing, coughing, sneezing, regulates vital functions including breathing, heartbeat, blood pressure
pons location and function
connects two halves of cerebellum, integration of movements in the right and left sides of body
cerebellum location and function
balance and posture (in conjunction with basal ganglia and motor cortex); vital to coordinated and refined motor movements; timing and coordination of actions and correction of errors while performing actions; sensorimotor learning, ability to shift attention from one stimulus to another
basal ganglia
initiation of motor actions
abnormalities in cerebellum linked to
autism, schizophrenia, ADHD
damage can cause
ataxia
ataxia
slurred speech, severe tremors, and loss of balance (similar to intoxication)
hindbrain structures
pons, medulla cerebellum
midbrain structures
superior/inferior colliculi, substantia nigra, reticular formation
superior and inferior colliculi route what
visual and auditory information (respectively)
substantia nigra involved in
motor activity, reward system
reticular formation location
from spinal cord through hind and midbrain into hypothalamus in forebrain
reticular formation consists of ? nuclei
90
reticular formation function
respiration, coughing, vomiting, posture, locomotion, REM sleep
Reticular Activating System (RAS) vital to
consciousness, arousal, wakefulness; screens sensory input during sleep, awakens if necessary
Damage to RAS
disrupts sleep-wake cycle, can produce permanent coma-like sleep state
Anesthetics work on what
deactivating neurons in reticular formation
forebrain structures
thalamus, hypothalamus, basal ganglia, limbic system
thalamus involved in
motor activity, language, memory, acts as relay station for all senses except olfaction
wernicke-korsakoff syndrome damage
thiamine deficiency causes atrophy in thalamus
wernicke’s encephalopathy
mental confusion, abnormal eye movements, ataxia
korsakoff’s syndrome
severe anterograde amnesia, retrograde amnesia, confabulation
hypothalamus involved in
hunger thirst, sex, sleep, body temp, movement, emotional reations
damage to hypothalamus
can cause uncontrollable laughter, aggression
hypothalamus function
monitors body’s internal states and initiates responses to maintain homeostasis through influence on ANS and pituitary and other endocrine glands
suprachiasmatic nucleus
mediates sleep-wake cycle, circadian rhythms
mammilary bodies involved in what
learning and memory
basal ganglia consists of what structures
caudate nucleus, putamen, globus pallidus (forebrain) and substantia nigra (midbrain)
basal ganglia involved in what
planning, organization, coordinating voluntary movement, regulating amplitude and direction of motor actions, sensorimotor learning and stereotyped species-specifc motor expressions of emotional state (eg. smile, frown, run)
What disorders associated with basal ganglia
Huntington’s, Parkinson’s, Tourette’s, OCD, ADHD
ADHD associated with what structural problems
smaller-than-normal caudate nucleus, globes pallid us and prefrontal cortex
What psychiatric symptoms associated with basal ganglia
mania, depression, OCD symptoms, psychosis
Limbic system structures
amygdala, hippocampus, cingulate cortex
amygdala function
integrates, coordinates, directs motivational and emotional activities, attaches emotions to memories, involve in recall of emotionally-charged experiences
flashbulb memories happen where
amygdala
Kluver and Bucy syndrome (1938)
bilateral lesions in amygdala and temporal lobes reduces fear and aggression, increase docility and compulsive oral exploratory behaviors, alters dietary habits (vegetarian monkeys become meat eaters), produces hypersexuality and psychic blindness
psychic blindness
inability to recognize significance or meaning of events/objects
hippocampus
associated more with learning and memory, processing spatial, visual, and verbal information and consolidating declarative memories; converts short-term declarative memories to long-term
epilepsy removal of medial temporal lobes causes
anterograde amnesia and retrograde amnesia for events occurring up to three years prior to surgery
cingulate cortex location and function
surrounds corpus callosum, involved in attention, emotion, perception and subjective experience of pain (particularly anterior)
Contralateral representation
for most sensory and motor functions, left controls right side of body except olfaction (left to left, right to right) and visual which goes to both sides – info from right visual field of each eye goes to left hemisphere and info from left visual field of each eye goes to right
Left hemisphere / right hemisphere function
95-99% of right handed people
50-60% of left-handed people
Left = written, spoken language, logical analytical thinking
Right = spatial, creativity, facial recognition
Which ear do people recall more digits
heard by ear that is contralateral to their dominant hemisphere, usually right ear
Frontal lobe consists of what
primary motor cortex, supplementary motor area, premotor cortex, broca’s area, prefrontal cortex
primary motor cortex location and function
located in precentral gyrus, movement
damage to motor cortex causes
loss of reflexes, flaccid hemiplegia (loss of muscle tone) in areas contralateral to damage
supplementary motor area (SMA) function
planning and control of movement; learning new motor sequences; motor imagery - mental representation of motor movement
premotor cortex location and function
located anterior to primary motor cortex; control of movement in response to external/sensory stimuli
broca’s area
located in inferior frontal region (usually on left); major motor speech area
damage to broca’s area
expressive aphasia, difficulties producing written and verbal language
Prefrontal cortex impacts performance on what tests
problem solving and creativity, attention, executive function
PFC abnormalities related to what mental d/os
Schizophrenia, ADHD, dementia
Damage to dorsolateral PFC results in; characteristics of individuals
dorsal convexity dysexecutive syndrome: impaired judgment, insight planning, and organization
concrete and perseverative, trouble learning from experience, neglect hygiene, reduced sexual interest, apathetic
Damage to orbitofrontal PRC results in; characteristics of individuals
orbitofrontal disinhibition syndrome (pseudopsychopathy); emotional lability, distractability, poor impulse control, impaired social insight
explosive aggressive outbursts, inappropriate jocularity, unusual or inappropriate sexual behavior, make lewd comments
Damage to mediofrontal area results in; characteristics of individuals
mesial frontal apathetic syndrome (pseudodepression); impaired spontaneity, reduced emotional reactions, diminished motor behavior and verbal output, lower-extremity weakness, sensory loss
Describe themselves as bored, lacking motivation, seem depressed but don’t have vegetative symptoms, negative cognitions, dysphoria characteristic of major depression
Parietal lobe location; function
located on post central gyrus, contains somatosensory cortex, governs pressure, temperature, pain, proprioception, gustation
apraxia
inability to perform skilled motor movements in the absence of impaired motor functioning
tactile agnosia
inability to recognize familiar objects by touch
asomatognosia
failure to recognize parts of one’s body
anosognosia
inability to recognize one’s own neurological symptoms ore other disorder
lesions in right parietal lobe cause
contralateral neglect (loss of knowledge about or interest in left side of body)
lesions in left parietal lobe
ideational apraxia (inability to carry out a sequence of actions); ideomotor apraxia (inability to carry out a simple action in response to a command
Grestmann’s syndrome
finger agnosia, right-left confusion, agraphia, acalculia
agraphia
AKA dysgraphia - inability to write
acalculia
inability to perform simple mathematical calculation
where is somatosensory cortex
parietal lobe
where is auditory cortex
temporal lobe
where is wernicke’s area
temporal lobe usually left
lesions in auditory cortex may cause
auditory hallucinations, auditory agnosia, other disturbances in auditory sensation and perception
lesions in wernicke’s area
receptive aphasia and abnormal language production
electrical stimulation of temporal lobe can elicit
complex, vivid memories previously forgotten
lesions to temporal lobe
retrograde and anterograde amnesia for semantic and episodic memories
where is visual cortex
occipital lobe
posterior versus anterior function
posterior - macular vision (central retina)
anterior - peripheral vision
apperceptive visual agnosia
unable to perceive objects despite intact visual acuity
associative visual agnosia
unable to recognize object of focus as result of impaired memory or access to semantic knowledge
damage to occipital lobes can cause
apperceptive or associative visual agnosia, visual hallucinations, cortical blindness
left occipital damage can cause
simultanagnosia - inability to see more than one thing or aspect of an object at a time
lesions at junction of occipital, temporal, and parietal lobes can cause
prosopagnosia - inability to recognize familiar faces
