W7 MHS1101 Nervous System 3

Flashcards about the nervous system's blood supply and cerebrospinal fluid.

Vertebral and internal carotid arteries

Main arteries that deliver nutrients and oxygen to the brain and spinal cord.

Dural venous sinuses

Structures that drain blood from the brain into the internal jugular veins.

Vertebral Arteries

Arteries that branch from subclavian arteries and ascend through the neck via foramina transversaria of cervical vertebrae.

Internal Carotid Arteries

Arteries that branch from common carotid arteries and ascend through the neck in the carotid sheath.

Posterior spinal artery

Formed by vertebral arteries fusing, supply ascending (sensory) pathways.

Anterior spinal artery

Formed by vertebral arteries fusing, supply descending (motor) pathways.

Basilar artery

Formed by the fusion of the vertebral arteries at the ventral surface of the pons.

Basilar artery

Supplies the pons, cerebellum and internal ear

Circle of Willis

Ring connecting cerebral arteries on each side, ensuring collateral blood flow.

Anterior Cerebral Artery

Supplies medial surface of hemisphere above corpus callosum, olfactory bulb/tract.

Posterior Cerebral Artery

Supplies occipital lobe (visual cortex), temporal lobe, thalamus, hypothalamus.

Middle Cerebral Artery

Supplies most of the lateral/external surface of hemispheres, corpus striatum, internal capsule.

Stroke (Cerebral Vascular Accident)

Death or damage of brain tissue due to vascular causes.

Occlusive stroke

Vessel blockage leads to ischaemia.

Haemorrhagic stroke

Vessel rupture, blood leakage, and haematomas

Venous Drainage of Brain

Superficial veins in subarachnoid space and deep veins which form the internal cerebral vein

Dural Venous Sinuses

Channels with walls containing dura, periosteum and endothelium, terminating at the jugular foramen

Arachnoid Granulations

Outpouchings that allow CSF absorption into venous circulation.

Ventricles

Fluid-filled spaces in the brain, continuous with the central canal of the spinal cord; lined with ependymal cells.

Falx cerebri

Fold of the meningeal cranial dura between cerebral hemispheres, containing superior/inferior sagittal sinuses

Tentorium cerebelli

Fold of the meningeal cranial dura that separates cerebrum and cerebellum, containing transverse sinus.

Falx cerebelli

Fold of the meningeal cranial dura that divides cerebellar hemispheres.

Cerebrospinal Fluid (CSF)

Fluid that surrounds all CNS surfaces; supports brain, cushions neural tissue, transports nutrients/wastes.

Choroid plexus

Specialized ependymal cells/capillaries that secrete CSF into ventricles (~500ml/day)

Arachnoid villi/granulations

Outgrowths of arachnoid membrane into superior sagittal sinus, absorb CSF into venous system.

Hydrocephalus

Accumulation of CSF due to impaired absorption/drainage.

Blood-Brain Barrier (BBB)

Isolates CNS from general circulation; formed by tight junctions between CNS capillary endothelial cells.

Blood-CSF Barrier

Tight junctions between specialized ependymal cells of choroid plexus capillaries, restricts transfer.