Fill in the Blanks Nervous System Online version In this game you will be tasked with filling in the name of the correct meninges based on the definition given. by Kennedy Swift 1 Mater postiosteal layer Pia Meningeal meningeal inner outer dural meningeal Postiosteal Dura Mater 2 layer Mater middle Arachnoid folds The is the most layer and lays directly on the surface of the brain and attaches directly to the brain and spinal cord . It is filled with cerebrospinal fluid , and protects blood vessels . The is the layer that has a spider web like appearance . It possesses arachnoid trabeculae that projects into the pia mater and reabsorbs the CSF to the blood . , the most layer consist of layers the and the layers . The folds inward to form several double thickness sheets known as , which helps hold the brain in place . Lastly , the adheres to the internal surface of the cranium and for majority of its course lies directly touching the layer . Meningeal vessels course between this layer and the cranium .