Hoofdstuk 3 Behavioral geography of the brain Flashcards
What do we call the product of a myriad of complx neuropsychological and biochemical interactions involving the whole brain?
Behaviour
What has the ability to regulate behaviour
The neuron
What are glia cells?
Supporting brain cells
What do glia cells do?
They facilitate neural transmission and play a role in synaptic functioning and neural signaling
What do Astrocytes cells do?
They play a role as a component of the blood brain barrier
What do Oligodendroglia cells do?
They form myelin of axonal sheats
What is coursing fasculi?
Impulse transmitting axonal bundles
How do neurons communicate?
Through neurotransmitters
What are the key neurotransmitters?
Acetylcholine, dopamine, norepinephrine, serotonin, glutamate and GABA
True or false: When a circuit loses a sufficiently great number of neurons, the broken circuit can neither be reactivated nor replaced
True
What is apoptosis?
Programmed cell death
What are the three major anatomical divisions of the brain?
Hindbrain, midbrain, forebrain
What runs through the ventricles?
Cerebrospinal fluid (CFS)
Blockage somewhere within the ventricular system affects CFS flow producing what?
Obstructive hydrocephalus
Where does the corticospinal tracts crosses the midline?
In the medulla
Where does the hindbrain consists of?
Pons, medulla and cerebellum
What functions does the hindbrain control?
Respiration, blood pressure and heartbeat
What does the recticular formation do?
Mediates complex postrual reflexes, contributes to smoothness of muscle acitivity and maintain muscle tone. Also controls wakefulness and alerting mechanisms.
Brainstem lesions involving the reticular activating system (RAS) give?
Sleep disturbances and global disorders of consciousness
Lesions of the pons may cause?
Motor, sensory and coordination disorders including disruption of ocular movements and alterations in consciousness
Cerebellar (cerebellum) damage is commonly known to produce problems of?
Fine motor control, coordination and postural regulation. Dizziness (vertigo) and jerky eye movements may also accompany cerebellar damage
What can be disrupted in cerebral lesions?
Abstract reasoning, verbal fluency, visuospatial abilities, attention, memory, speed of processing and emotional modualtion (oftewel wat niet)
Where is the substantia nigra located?
In the midbrain
Midbrain lesions can produce?
Paralysis, specific movement disabilities, tremor and even impaired memory retrieval
Which two structures does the diencephalon consists of?
Thalamus and hypothalamus
Thalamic lesions are accompanied with?
Compromised learning (anterograde amensia) and defective recall of past information (retrograde amnesia). Body sensations may de degraded with damage to specific thalamic nuclei and also identification of what is felt (tactile object agnosia)
What are some functions of the hypothalamus?
Physiologically based drives as appetite, sexual arousal, and thirst (regulating homeostatis)
Lesions to hypothalamic nuclei can result in?
Obesity, disorders of temperature control, fatigue and diminished drive states
What is the telecephalon?
The two halves of the forebrain (two hemispheres)
Which disorder entails amnestic patients with bilateral diencephalic lesions?
Korsakoff patients (tend to show disturbances in time sense and the ability to maken temporal discriminations)
Which structures does the basal ganglia include?
Caudate, putamen and globus pallidus
Damage to the basal ganglia results in?
Movements disturbances/ disorders but does not result in paralysis since they are not motor nuclei in a strict sense
Damage to the basal ganglia is seen in patients with?
Parkinsons and Huntingtons
Difficulties in starting activities and in altering the course of ongoing activities characterize aspects of (PD or HD)?
PD
Patients having trouble initiating cognitive processes along with impaired movements characterize apects of (PD or HD)?
HD
Alterations in basal ganglia circuits involved with nonmotor areas have been implicated in which neuropsychiatric disorders?
Schizophrenia, OCD, depression, Tourette’s, autism and ADD
The limbic systems includes which structures?
Amygdala, cingulate gyrus and hippocampus
The cingulate gyrus has important influences on?
Attention, response selection, processing of pain, and emotional behavior
Lesions in cerebral white matter cause and are often associated with?
Loss of connections between lower and higher centers or between cortical areas within a hemisphere or between hemispheres - associated with slowed processing speed and attentional impairments
Surgical section of the corpus callosum results in?
Cut off of direct interhemispheric communication (epilepsy treatment)
Where does grey matter consists of?
Nerve cell bodies and their synaptic connections
The centers in each cerebral hemisphere predominantly mediate the activities of the contralateral/ ipsilateral side of the body?
Contralateral
What does the homunculus entail?
The amount of cortex associated with each body portion is roughly proportional to the number of sensory or motor nerve endings
Where does the right hemisphere specialises in?
Non-verbal information like visual patterns or auditory signals, speech intonation (prosody)
Patients with right hemisphere damage may be quite fluent and wordy but on the other hand?
Illogical and given to loose generalizations and bad judgement
Self recognition, self awareness, apathy and poorer social functioning are associated with predominantly right/ left hemisphere involvement?
Right
Where is the primary visual cortex located?
Posterior portion of the occipital lobe
Where is the primary sensory area located?
Posterior to the central sulcus in the parietal lobe
Where is the primary auditory cortex located?
On the uppermost fold (or inferior to the Sylvian gyrus) of the temporal lobe
What is cortical blindness?
When a patient had lost the capacity to distinguish forms or patterns while remaining responsive to ligh and dark
What is blindsight?
It is a form of visually responsive behavior without experiencing vision (information in the blind visual field may project trough alternate pathways)
What is visual agnosia?
A condition in which a person can see but cannot recognize or interpret visual information
To what does associative agnosia refer? (due to left hemisphere lesion)
Failure of recognition due to defective retrieval of knowledge pertinent to a given stimulus
To what does apperceptive agnosia refer?
It is a failure in recognition that is due to a failure of perception. They can not intergrate the perceptual elements of the stimulius
What is color agnosia?
Loss of the ability to retrieve color knowledge, not deu to faulty perception or impaired naming
What is pantomime agnosia?
The inability to comprehend pantomimes occurs with lesions confined to the occipital lobe
What is pure alexia?
A reading problem that seems form defects of visual recognition (parietal damage)
What is prosopagnosia? (mostly from bilateral occipital damage)
The inability to recognize familair faces and to learn new faces (face agnosia)
What do people with prosopagnosia recognize?
Facial expressions of emotion and accurate determinations of gender and age
Which pathway runs from the top side of the cerebrum, from occipital to parietal and is called the ‘where’ pathway?
Dorsal pathway
In what is the dorsal pathway involved?
With spatial analysis and sparial orientation (where)
Which pathway runs form the bottom, from the occipital lobe to the temporal lobe and is called the ‘what’ pathway?
Ventral pathway
In what is the ventral pathway involved?
Information about shapes and patterns
What is apraxis?
Inability to perform previously learned purposeful movements
Lesions in either hemisphere involving the somatosensory association areas can produce?
Tactile agnosia or astereognosis (inability to identify an object by touch)
Defects araising from left posterior hemisphere lesions are?
Fluent aphaisa, communcation disorders, and acalculia
Defects araising from right posterior hemisphere lesions are?
Inattention (impaired attention to and awareness of stimuli presented to half of personal space), impairment of topographical or spatial tought and memory
What is the primary function of the temporal cortex?
Hearing, auditory memory storage and auditory perceptual organization
What is pure word deafness?
The inability to comprehend spoken words despite intact hearing
What is auditory agnosia?
Inability to recognize auditory presented environmental sounds independent of any deficit in processing spoken language
What is Wernicke’s aphasia?
Impaired language comprehension. Motor production of speech stays intact
Damage to … of the temporal lobe is responsible for memory impairments in early Alzheimer’s disease
Hippocampus
Old/ New memories do not appear to be stored in the hippocampus
Old
Which structure in the temporal lobe is necessary for processing facial expressions of fear as well as facial emtion in social contexts?
The amygdala
Where is the primary motor cortex located and what is its function?
Anterior of the central gyrus. It mediates movements on the opposite side of the body. Has important connections with the cerebellum, basal ganglia and motor divisions of the thalamus
Lesions in the premotor area result in?
Disruption in integration of the motor components of complex acts, resulting in uncoordinated movements
What is hypokinesia?
Sluggish movement activation
What is motor impersistence?
Reduced ability to maintain a motor act e.g. eye closure
What is perseveration?
When patients repeat a movements long past the point where it is appropriate and adaptive
What is Broca’s aphasia?
Form of aphasia in which the person knows what they want to say but is unable to produce the words or sentence
Prefrontal lobe disorders have more to do with the how/ what of the response
How a patients responds - inappropriate approach to problems not a lack of knowlegde
Damage to the ventromedial prefrontal cortex is linked to problems with?
Impulse control and inhibition
Damage to the dorsolateral prefrontal cortex is linked to what kind of deficits?
Intellectual deficits (specifically ‘fluid’)
Patients with frontal amnesia seem to have problems in prospective memory and also in … yet, when prompted or given specific questions, they may produce some responses
Recall
