Cerebral Hemisphere Flashcards
What type of astrocyte maintains spacial separation between mini and macro columns?
vellate astrocytes
Autism is thought to be a ‘columnopathy’ associated with what changes in columns and white matter?
increased number of mini-columns and increased subcortical white matter (increased cortico-cortical connections)
List 4 main cortical signs
aphasia
agnosia
eye deviation
neglect
What is Apraxia?
the inability to carry out a learned skilled movement despite intact sensory, motor and language functions
Lesions of the prefrontal cortex may cause ‘frontal release signs’ what is this phenomenon and why does it occur?
in adults, the prefrontal cortex inhibits reflexes which are normally present in infants; lesions in adults of the prefrontal cortex may unmask these reflexes; always pathological in an adult
Grasp Reflex
can be elicited by stroking the palm of the hand; the patient will grasp the finger, even if instructed not to do so
Glabellar Reflex
repetitive taps between the eyebrows will cause the patient’s eyes to blink, even if they are instructed not to; in a normal individual, a blink might occur with a couple of taps and then stop
Suck Reflex
gently touching the lips may evoke a sucking response
Snout Reflex
light tapping of the closed lips or nasal philtrum near the midline will evoke a pouting or pursing of the lips
Rooting reflex
gently stroking the cheek will cause the individual to turn their mouth towards an object (tactile rooting) or to turn their eyes towards an object brought into their field of view (visual rooting)
deep white matter of the hemispheres lies immediately beneath the cortex is called? (two names)
Medullary Center or centrum semiovale
Association Pathways connect what?
white matter pathways that connect areas within a single hemisphere
Lesion where results in conduction aphasia? Describe conduction aphasia
arcuate fasciculus
understand and can speak language; yet they give incoherent and inappropriate responses to questions; they appear to have difficulty in integrating what is heard with what they want to say
Where are the cell bodies of origin for the cingulum and function of cingulum
cingulate gyrus
the cingulum is a major pathway allowing the emotional content of our experiences to be integrated with our memories/cognition
Commissural pathways connect what?
axons which connect neurons between the two hemispheres (corpus callosum)
Projection pathways connect what
represent axons going to and from the cortex (ascending and descending axons)
From lateral to medial, name the 3 capsules in a coronal section of the brain
extreme, external, and the internal capsules
Describe the blood supply to all the limbs of the internal capsule and what is the most common area of stroke within the internal capsule?
ACA - Anterior Limb
MCA - Genu
Lteral Striate branches of MCA - Posterior limb
Posterior limb of the internal capsule is a major site for both hemorrhagic and ischemic strokes
Basal Ganglia are derived from what embryological origin?
Prosencephalon
Dorsal Striatal structures of the basal ganglia are primarily involved with what?
motor behavior
Ventral striatal structures of basal ganglia are primarily involved with what?
non-motor limbic functions
What deep brain structures make up the corpus striatum?
caudate, putamen, and globus pallidus
What deep brain structures make up the (neo)striatum?
caudate and putamen
What deep brain structures make up the Lenticular Nucleus?
putamen and globus pallidus
