human brain stem, cranial nerves and blood supply of central nervous system, circle of willis, internal organs anatomy body part

abducens accessory anatomy artery biology blood brain callosum care cerebellum cerebrum chiasm circle circulation cord corpus cortex cranial design diagram facial flat gland glossopharyngeal graphic head health human hypoglossal hypothalamus illustration internal medical medulla memory nerves nervous neurology oculomotor olfactory optic organs pituitary pons spinal stem structure supply surgery system trigeminal trochlear tumor vagus vector vestibulocochear willis