Flashcards in Anatomy and Physiology X Deck (25)
What is global aphasia?
Nonfluent aphasia with impaired comprehension (p.420)
What regions of the brain are affected in patients with global aphasia?
Both Broca's and Wernicke's areas (p.420)
What is conduction aphasia?
Poor repetition but fluent speech and intact comprehension (p.420)
Damage to what area causes conduction aphasia?
Damage to the arcuate fasciculus (p.420)
What surfaces of the brain is supplied by the anterior cerebral artery?
The anteromedial surfaces (p.420)
What surfaces of the brain is supplied by the middle cerebral artery?
The lateral surfaces of the brain (p.420)
What surfaces of the brain are supplied by the posterior cerebral artery?
The posterior and inferior surfaces of the brain (p.420)
Where are the two watershed zones of the brain?
Between anterior cerebral/ middle cerebral arteries; between the posterior cerebral/ middle cerebral arteries (p.420)
Name a typical cause of watershed infarction?
Severe hypotension (p.420)
Name two symptoms associated with watershed infarction.
Upper leg/ upper arm weakness; defects in higher-order visual processing (p.420)
How is brain perfusion regulated?
Tight autoregulation primarily driven by PCO2 (p.421)
In instances of severe hypoxia, how is brain perfusion regulated?
PO2 modulates brain perfusion in addition to PCO2 (p.421)
What is therepeutic hyperventillation?
Decreasing PCO2 to decrease ICP in cases of acute cerebral edema (stroke, trauma, etc) via decreasing cerebral perfusion (p.421)
When is therepeutic hyperventillation used?
During cases of acute cerebral edema to reduce ICP (p.421)
At what point does hypoxemia increase cerebral perfusion pressure?
Cerebral blood flow is only increased when PO2 is less than 50mmHg (p.421)
When does cerebral perfusion pressure increase proportionally to PCO2?
Cerebral blood flow increases proportionally to PCO2 until PCO2 > 90 mmHg; It levels off at this point (p.421)
What three arteries compose the anterior circulation of the brain?
MCA, ACA, Lateral striate artery (p.422)
What four functional areas does the MCA supply?
The motor cortex (upper limb and face); Sensory cortex (upper limb and face); Temporal lobe (Wernicke's area); Frontal lobe (Broca's area) (p.422)
What symptoms are associated with an infarction of the MCA?
Contralateral paralysis of the upper limb and face; contralateral loss of sensation of the upper limb and face; aphasia if in dominant (usually left) hemisphere; hemineglect if lesion affects non dominant side (usually right side) (p.422)
What two functional areas are supplied by the ACA?
Motor cortex- lower limbs; sensory cortex- lower limbs (p.422)
What symptoms are associated with an infarction of the ACA?
Contralateral paralysis of the lower limb; contralateral loss of sensation of the lower limb (p.422)
What two functional areas are supplied by the lateral striate arteries?
The striatum and internal capsule (p.422)
What symptoms are associated with an infarction of the lateral striate arteries?
Contralateral hemiparesis/hemiplegia (p.422)
What arteries are commonly infarcted in the setting of lacunar infarcts?
The lateral striate arteries (p.422)