Lecture 2 - Neuroanatomy of Language

everything located anterior to the central fissure is … while everything posterior is …

anterior - motor

posterior - sensory

describe the ‘where’ vs ‘what’ pathway

where - dorsal pathway; tells us where things are in space and orients us (e.g. how far to move hand to grab a water bottle)

what - ventral pathway; tells us meanings and concepts (e.g. telling you that the thing you grabbed is a water bottle)

describe information located caudally vs rostrally

caudal - more concrete information (e.g. vision processing)

rostral - more abstract information (e.g. vision becomes attention awareness)

central nervous system is covered by 3 membranes collectively called …

the meninges

describe the meningeal layers

dura - outermost, composed of tough, fibrous connective tissue, between skull and brain

arachnoid - middle, delicate membrane, spider-web appearance due to plenty of blood vessels

pia - innermost, clings directly to the brain and spinal cord

describe the subarachnoid space

space between pia and arachnoid membrane

includes blood vessels and web-like processes of the arachnoid membrane (makes it common place for hemorrhaging); also includes CSF

describe purpose of CSF and what can happen when there is a loss of CSF

supports, nourishes and cushions the brain

loss = severe stabbing pains each time the head jerks

what is the system of 4 interconnected hollow chambers filled with CSF in the center of the brain?

ventricular system (helps add buoyancy to the brain and different channels work together to move CSF around)

name the ventricles and their locations

two lateral ventricles (one in each hemisphere), located within the cerebral hemisphere (telencephalon)

third ventricle, centrally located in forebrain (diencephalon)

fourth ventricle, small chamber in hindbrain (metencephalon)

third and fourth ventricles communicate via …

cerebral aqueduct — narrow channel that runs through the midbrain

the ventricular system is continuous with the … and is connected to … via …

continuous with central canal of spinal cord and is connected to the subarachnoid space via 4th ventricle allowing for CSF to continuously surround brainstem, cerebellum and cortex

where is CSF produced?

choroid plexuses, located on walls/roof of ventricles

brain receives … % of the body’s blood supply

15-20%

the brain is supplied with blood via two pairs of arteries. which pairs of arteries?

vertebral and internal carotid

vertebral arteries come together at … to form …

at base of brain to form the singular basilar artery

where does the basilar artery continue?

joins blood supply of internal carotid which proceeds to a ring at the base of the brain (Circle of Willis)

what is the circle of willis

safety mechanism - if one artery gets blocked, the circle will still provide blood to the brain

internal carotid arteries arise from …

common carotid arteries

internal carotid arteries branch off into which arteries?

anterior (ACA), middle (MCA) and posterior (PCA) which covers the surface of each hemisphere

the anterior cerebral artery is distributed mostly throughout …

medial surface of cortex extending posteriorly into parietal lobe

interruption to the ACA results in …

paralysis of legs and feet (decreased blood supply to motor cortex where lower extremities are represented)

prefrontal lobe symptoms (impaired thinking, reasoning and planning)

MCA branches to …

most of lateral cortex

which is the largest cortical artery

MCA

MCA has main vessel within …

Sylvian fissure

MCA supplies … and … areas involved in …

motor and sensory areas involved in speech, audition, and language

list the particular areas supplied by MCA

• somatosensory cortex

• motor cortex

• Broca’s area

• Heschl’s gyrus

• Wernicke’s area

• angular and supramarginal gyrus

true or false: language areas surround the central fissure

false; surround the Sylvian fissure

PCA covers … surface of which lobes?

medial surface of occipital lobe and base of temporal lobe

PCA supplies … area

visual

occlusion of basilar artery, which supplies blood to … arteries, results in …

blood to posterior arteries

results in total blindness and cerebellar symptoms

a stroke is also referred to as…

a cerebrovascular event

what is a midline shift?

physical displacement of the brain’s central structures caused by force of a lesion or swelling

what is mass effect?

pushing force of an expanding lesion or swelling on surrounding brain tissue

a midline shift/mass effect indicates…

severe stroke

neurological disorders can occur when …

blood supply to the brain is interrupted/stopped

what is ischemic stroke

occlusive vascular pathologies (blockage), most common form of stroke (~85%)

thrombosis

localized build-up causing a blood clot in the brain

embolism

embolus (particle traveling through the bloodstream) blocks artery

ischemic refers to…

lack of oxygen

what is our bodies natural response when it detects something foreign

blood clotting to remove/clear out the foreign material

what is a thromboembolic stroke

when there is plaque build-up that breaks away and mixes with a blood clot and ends up blocking an artery in a different area of the body

what is the biggest risk factor of thromboembolic strokes?

diabetes

risk factor for embolic strokes

atrial fibrillation (inconsistent heart beat)