arachnoideala

Arachnoideala is a term used in some medical languages to refer to the arachnoid mater and its associated arachnoid structures within the meninges. The arachnoid mater is the middle meningeal layer that lies between the dura mater (outer) and the pia mater (inner). It is a thin, translucent membrane that forms a loose, spiderweb-like network over the brain and spinal cord. The subarachnoid space, between the arachnoid and the pia, contains cerebrospinal fluid and major cerebral vessels.

Arachnoid trabeculae are delicate threads that span the subarachnoid space, anchoring the arachnoid to the pia mater. Arachnoid villi or granulations protrude into the dural venous sinuses and serve as sites of CSF reabsorption into the bloodstream. The arachnoid membrane participates in cushioning the CNS and contributes to the regulation of the chemical environment around neural tissue.

Clinically, disruption or inflammation of the arachnoid membrane can occur in conditions such as arachnoiditis, arachnoid cysts, or meningitis. Subarachnoid hemorrhage involves bleeding into the subarachnoid space, often from ruptured cerebral aneurysms, affecting the function of the arachnoid and CSF dynamics. Imaging modalities like MRI and CT are used to assess these conditions.

In embryology, the meninges develop from meningeal tissue surrounding the neural tube; the arachnoid and pia contribute to the subarachnoid space that houses CSF. The term arachnoideala may appear in non-English medical literature or Latin-derived texts to denote arachnoid-related structures.