Neuroanatomy
Laboratory 3
Brainstem and Cranial Nerves
Associated radiology modules: BRAINSTEM, CRANIAL NERVES
Brainstem BLOOD SUPPLY
The major blood supply to the brain is from two pairs of arteries, the vertebrals and the internal carotids. In general, the vertebrals supply the brainstem, the caudal diencephalon and the caudal and inferior cerebrum. The carotids supply the rostral thalamus and hypothalamus, the basal ganglia and the remainder of the cerebrum.
Vertebral Branches. The vertebral arteries enter the cranium via the foramen magnum near the junction of the medulla and spinal cord. They run along the medulla just ventral to the olives and lateral to the pyramids. Each vertebral artery gives off an anterior spinal branch. These fuse at the midline forming the anterior spinal artery, which descends down the medulla onto the cervical spinal cord. The branches of the anterior spinal artery penetrate the pyramids, supplying a ventral wedge of the medulla that includes the pyramids.
A more rostral branch arises from each vertebral, the posterior inferior cerebellar artery (PICA), before the vertebrals join at the midline to form the basilar artery. The posterior inferior cerebellar arteries each pass dorsally over the olives and around the middle of the medulla. Rostral branches of PICA supply the medulla up to the pons-medulla junction and caudal branches supply as far as the spinal cord. An exception to this distribution is the ventral wedge of the medulla served by the anterior spinal arteries. The posterior inferior cerebellar arteries continue onto the caudal-medial (inferior) aspect of the cerebellum near the midline and then extend laterally onto the inferior surface of the cerebellum.
At the pons-medulla junction, the vertebral arteries join to form the basilar artery, which then gives off the anterior inferior cerebellar arteries (AICA). This pair of arteries passes laterally around the pons to extend along the middle cerebellar peduncles onto the
Brainstem and Cranial Nerves
Associated radiology modules: BRAINSTEM, CRANIAL NERVES
Brainstem BLOOD SUPPLY
The major blood supply to the brain is from two pairs of arteries, the vertebrals and the internal carotids. In general, the vertebrals supply the brainstem, the caudal diencephalon and the caudal and inferior cerebrum. The carotids supply the rostral thalamus and hypothalamus, the basal ganglia and the remainder of the cerebrum.
Vertebral Branches. The vertebral arteries enter the cranium via the foramen magnum near the junction of the medulla and spinal cord. They run along the medulla just ventral to the olives and lateral to the pyramids. Each vertebral artery gives off an anterior spinal branch. These fuse at the midline forming the anterior spinal artery, which descends down the medulla onto the cervical spinal cord. The branches of the anterior spinal artery penetrate the pyramids, supplying a ventral wedge of the medulla that includes the pyramids.
A more rostral branch arises from each vertebral, the posterior inferior cerebellar artery (PICA), before the vertebrals join at the midline to form the basilar artery. The posterior inferior cerebellar arteries each pass dorsally over the olives and around the middle of the medulla. Rostral branches of PICA supply the medulla up to the pons-medulla junction and caudal branches supply as far as the spinal cord. An exception to this distribution is the ventral wedge of the medulla served by the anterior spinal arteries. The posterior inferior cerebellar arteries continue onto the caudal-medial (inferior) aspect of the cerebellum near the midline and then extend laterally onto the inferior surface of the cerebellum.
At the pons-medulla junction, the vertebral arteries join to form the basilar artery, which then gives off the anterior inferior cerebellar arteries (AICA). This pair of arteries passes laterally around the pons to extend along the middle cerebellar peduncles onto the