pia mater

noun

pia ma·​ter ˈpī-ə-ˌmā-tər  ˈpē-ə-ˌmä- 

: the thin vascular membrane that invests the brain and spinal cord internal to the arachnoid and dura mater

Word History

Etymology

Middle English, from Medieval Latin, from Latin, tender mother

First Known Use

14th century, in the meaning defined above

Medical Definition

pia mater

noun

pia ma·​ter -ˈmāt-ər 

: the delicate and highly vascular membrane of connective tissue investing the brain and spinal cord, lying internal to the arachnoid and dura mater, dipping down between the convolutions of the brain, and sending an ingrowth into the anterior fissure of the spinal cord

called also pia