Arachnoid granulation: Arachnoid granulations (or arachnoid villi) are small protrusions of the arachnoid (the thin second layer covering the brain) through the dura mater (the thick outer layer). They protrude into the venous sinuses of the brain, and allow cerebrospinal fluid (CSF) to exit the sub-arachnoid space and enter the blood stream.Meningitis Vaccine ProjectFalx cerebri: The falx cerebri is also known as the cerebral falx, named from its sickle-like form. It is a large, crescent-shaped fold of meningeal layer of dura mater that descends vertically in the longitudinal fissure between the cerebral hemispheres.Metastrongylus: Metastrongylus is a genus of nematodes of the family Metastrongylidae, usually found as lungworms in pigs and sometimes causing verminous bronchitis. It causes a disease called metastrongylosis.Choroid plexus cystAngiostrongylus costaricensis: Angiostrongylus costaricensis is a parasitic nematode.Fibrous tissue neoplasm: A fibrous tissue neoplasm is a tumor derived primarily from Fibrous connective tissue.MeningiomaPug: The Pug is a breed of dog with a wrinkly, short-muzzled face and curled tail. The breed has a fine, glossy coat that comes in a variety of colours, most often fawn or black, and a compact square body with well-developed muscles.Meningeal carcinomatosis: Meningeal carcinomatosis is a condition in which a solid tumor diffusely spreads to the leptomeninges. Lung tumors, breast tumors, and malignant melanoma comprise the majority of solid tumors spreading to the leptomeninges.