lecture 1 Flashcards
Precentral gyrus of frontal lobe
primary motor cortex, origin of descending motor pathway, initiate voluntary movements
Premotor and supplemental motor areas (frontal)
part of precental, nearby portions of superior and middle frontal gyri
Broca’s area (frontal)
inferior frontal gyrus of one hemisphere (usually left), production of spoken and written language
Prefrontal cortex (frontal)
rest of frontal lobe, executive functions (personality, foresight, insight)
Postcentral gyrus (parietal)
is primary somatosensory cortex, concerned with initial processing of tactile and proprioceptive information
Inferior parietal lobule of one hemisphere (typically left)
involved with language comprehension
Rest of parietal cortex
complex aspects of spatial orientation and directing attention
superior surface of temporal lobe, part of superior temporal gyrus
Primary auditory cortex
posterior aspect of one hemisphere (usually left) of temporal lobe
Language comprehension, Wernike’s area
much of temporal lobe
Higher order visual processing
medial temporal lobe
Learning & memory (technically part of limbic lobe)
Occipital functions
More or less exclusively visual in function
Primary visual cortex in banks of calcarine sulcus and a bit of surrounding cortex
Rest of lobe consists of visual association cortex, involved in higher order visual processing
remember visual association areas also in temporal lobe
Limbic system
emotional responses, drive-related behaviors & memory
Limbic lobe
Mostly consists of cingulate and parahippocampal gyri
Path of CSF circulation
CSF is formed by choroid plexus in the ventricles. From the lateral and third ventricles CSF flows down the cerebral aqueduct (in the midbrain) to 4th ventricle and out the median (foramen of Magendie) and lateral (Luschka) apertures (one lateral aperture on each side) down the brainstem and spinal cord or around the brain surface to the arachnoid granulations and into the superior sagittal sinus.
Epidural hematoma
Tear of meningeal arteries blood between skull & dura
Subdural hematoma
tearing of bridging veins
Two pairs of vessels supply much of brain & cord:
Internal carotid and vertebral arteries
Anterior choroidal artery
Long and thin
Clinically significant, involved in strokes
Supplies many different structures optic tract, choroid plexus in temporal horn of lateral ventricle, deep structures (internal capsule, thalamus, hippocampus) sometimes cerebral peduncleRuns medially and enters longitudinal fissure
Anterior cerebral artery
Runs medially and enters longitudinal fissure
then it arches posteriorly and follows corpus callosum
Supplies medial parts of frontal and parietal lobes, not some branches extend over the dorsolateral surface
Note the 2 ACAs are connected by the anterior communicating artery
Middle Cerebral Artery
Runs laterally into lateral sulcus, divides into many branches
Supplies most of lateral cerebral hemispheres
Vertebral-Basilar System
Supplies brainstem & cerebellum
Vertebral arteries run along lateral medulla, fuse to basilar artery at pons
Prior to joining basilar artery each vertebral artery gives rise to:
Posterior spinal artery: supplies posterior 1/3 of spinal cord
Anterior spinal artery: join together in midline, resulting single artery supplies anterior 2/3 of cord
(Note these arteries get help caudal to cervical cord)
PICA: supplies inferior cerebellum and lateral medulla
Basilar artery
Bifurcates at midbrain into 2 PCAs
Prior to bifurcation gives rise to AICA and SCA
AICA: supplies anterior portions of the inferior surface of cerebellum (flocculus) and caudal pons
SCA: supplies superior cerebellum, caudal midbrain and rostral pons
Posterior cerebral artery
Branches supply medial & inferior surfaces of temporal and occipital lobes
Branches also go to rostral midbrain and posterior diencephalon
Thalamic functions
Significant and central importance to most CNS functions
No sensory information except olfaction reaches the cerebral cortex without a stop in the thalamus
Thalamus involved in motor system neural circuits, which are loops that involve the cerebellum and basal ganglia
Limbic system projections to cortex also stop in thalamus first
Hypothalamus
Inferior surface visible on base of the brain
Mammillary bodies
Infundibular stalk, connects hypothalamus with pituitary
Major visceral control center also has limbic functions
CN II
Optic nerve (II)
Join to form optic chiasm where half of the fibers cross the midline giving rise to the optic tract
Optic tract ends in thalamus
Embryologically part of diencephalon so part of CNS, not PNS
Cranial nerves: Midbrain
Oculomotor (III), emerges from interpeduncular fossa
Trochlear (IV), emerges from dorsal aspect of brainstem, the only one to do so
Cranial nerves: Pons
Trigeminal (V) Abducens (VI) Facial (VII) Vestibulocochlear (VIII) Emerges from cerebellopontine angle
Cranial nerves: Medulla
Glossopharyngeal (IX) Vagus (X) Accessory (XI) Emerges from upper cervical spinal cord, ascends into skull then reverses and goes back into neck Hypoglossal (XII)
Cerebellum: Anterior lobe (AL) is anterior to primary fissure
Flocculonodular lobe
Posterior lobe (PL)
Anterior lobe is spinal cord input, trunk & limb movement
Flocculonodular lobe eye movements and vestibular function
Posterior lobe input form cortex, coordinates voluntary movements
Basal ganglia
Caudate, putamen, globus pallidus and the major components
Striatium: caudate and putamen
Lenticular nucleus: putamen and globus pallidus
Separated from thalamus by the internal capsule, a fiber bundle interconnecting cortex and deep structures
Involved in movement control
Ventricles function
Cavity of embryologic neural tube, filled with CSF made by choroid plexus
Suspends brain, regulates extracellular fluid composition and route by which certain chemical messengers are distributed in the CNS