Contains cavity that contributes to fourth ventricle
(5) Medulla oblongata
Lies in posterior cranial fossa
Continuous with spinal cord
Contains inferior portion of fourth ventricle
(6) Cerebellum
Dorsal to pons and medulla
Beneath posterior cerebrum
Composed of two lateral hemispheres connected by vermis in midline
Important in
Maintenance of balance, posture and coordination
Timing and strength of contraction of musclesBrainstem
Parts of brain hidden by cerebral hemispheres and cerebellum
Contains third and fourth ventricles and cerebral aqueduct
Composed of
Midbrain
Pons
Medulla oblongata
Contains masses of gray matter, many of which are sensory and motor nuclei of cranial nervesArterial supply to the brain
Internal carotid artery
Arises in neck
Enters cranial cavity via carotid canals
Terminates as
Anterior cerebral artery-connected to opposite artery by anterior communicating artery
Middle cerebral artery
Joined to posterior cerebral artery near termination by posterior communicating artery
Vertebral arteries
Ascend through transverse foramina of C1-C6 cervical vertebrae
Perforate dura
Enter posterior cranial fossa via foramen magnum
Unite at posterior pons to form basilar artery
Ascends on clivus
Divides into two posterior cerebral arteries
Unite with internal carotid artery via posterior communicating arteries
Circle of Willis
Cerebral arterial circle
Composed of
Anterior communicating artery
Anterior cerebral arteries
Internal carotid arteries
Posterior communicating arteries
Posterior cerebral arteries
Areas supplied by anterior cerebral artery
Medial and superior brain
Frontal pole
Areas supplied by middle cerebral artery
Lateral brain
Temporal pole
Posterior cerebral artery
Inferior brain
Occipital polepage 67
page 68Meninges