KIN 4571 - brain blood flow & cerebrospinal fluid (CSF)

what are the branches of the common carotoid arteries?

external carotoid arteries and internal carotoid arteries

where can the external carotoid arteries be found in?

extracranial structures, e.g., meninges, scalp, face)

where can the internal carotoid arteries be found in?

rostral brain

what is the main branch of the subclaian arteries?

vertebral arteries

where can the vertebral arteries be found in?

caudal brain

what are the major blood supply of the cortex from the body?

internal carotoid artery (2) and vertebral artery (2)

what is the function of the internal carotid arteries?

supplies rostral area of the brain; part of the Circle of Willis

what is the internal carotid arteries divided into?

anterior cerebral artery and middle cerebral artery

what is the function of the anterior cerebral artery?

supplies the midline of the cortex; also part of the Circle of Willis

what is the function of the middle cerebral artery?

supplies the lateral cortex; NOT part of the Circle of Willis

what is the function of the vertebral arteries?

supplies caudal area of the brain; blood flower through the basilar artery to the Circle of Willis

what is the pathway of the vertebral arteries?

offshoot of the subclavian arteries (clavicle); join at the caudal end of the pons and form the basilar artery

where is the Circle of Willis?

located at the pons and midbrain levels

where is the basilar artery located?

along the midline of the pons (rostral) and branches to the posterior cerebral arteries to cortex and the posterior communicating arteries

what does the internal carotid arteries branch off to?

middle cerebral arteries to cortex and joined by anterior communicating artery

which would cause greater impairment: an arterial occlusion within the circle of willis or outside of it?

outside

what major arteries supply blood to the cerebral cortex?

anterior cerebral arteries, middle cerebral arteries, and posterior cerebral arteries

where does the anterior cerebral arteries supply blood to?

medial frontal love, medial parietal lobe, and superior part of limbic lobe

where does the middle cerebral arteries supply blood to?

lateral temporal lobe, lateral frontal lobe, lateral parietal lobe, and insula

where does the posterior cerebral arteries supply blood to?

inferior temporal lobe, occipital lobe, and inferior part of the limbic

what happens if there’s an occlusion in the inside of the circle of willis?

less impact because of compensatory blood flow

what happens if there’s an occlusion in the anterior cerebral artery (outside of the circle of willis)?

will affect the strength (frontal) & and sensation (parietal) in contralateral lower body

what happens if there’s an occlusion in the middle cerebral artery (outside of the circle of willis)?

will affect the strength (frontal) & sensation (parietal); also the language (lateral temporal)

what happens if there’s an occlusion in the posterior cerebral artery (outside of the circle of willis)?

will cause the loss of contralateral visual field (occipital) and will be unable to recognize usual stimuli (inferior temporal)

what is the cerebral spinal fluid primarily produced by?

choroid plexus commonly found in the ventricles

what is the cerebral spinal fluid primarily absorbed by?

arachnoid villi (granulations) commonly found in the superior sagittal sinus

what part of the ventricles is cerebral spinal fluid found in?

left/right lateral (1 and 2) ventricles (mostly), 3rd ventricles (little), and 4th ventricle (little)

what is the function of the cerebral spinal fluid?

used for CNS protection

what is the venous sinus?

large, vein like channels that drain venous blood and reabsorb cerebrospinal fluid from the brain and direct it into internal jugular veins

what are meninges?

the protective membranes that surround and cover the entire CNS (brain and spinal cord)

what are the layers of the meninges?

dura mater, arachnoid mater, and pia mater

what meninges layer forms the sinuses (venous system: drains blood and CSF)?

dura mater

what meninges layers form the subarachnoid space for CSF flow and cerebral arteries/veins?

arachnoid mater and pia mater

what does traumatic brain injury/skull fracture cause?

rupture of meningeal artery which separate the dura from the bone causing the compression of the cerebral cortex (extradural/epidural space)

what causes shaken baby syndrome?

rupture bridging vein leading to subdural hematoma then compression to the cerebral cortex (subdural space)

what causes a stroke?

a hematoma causing compression to cerebral cortex (subarachnoid space)

what is the pathway of cerebral spinal fluid?

lateral ventricles, 3rd ventricles, 4th ventricles, subarachnoid space around the brain and spinal cord, arachnoid villi, and superior/inferior sagittal sinus (cycle)