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ventricles in the brain.

A. Astrocyte: This is the most abundant neuroglial cell in the central nervous system, characterized by its star-shaped morphology and perivascular feet. These cells are essential for maintaining the blood-brain barrier, regulating the chemical environment of the interstitial fluid, and providing structural support to neurons. Their primary role is homeostatic and metabolic.

B. Schwann Cells: Schwann cells are glial cells of the peripheral nervous system that form the myelin sheath around axons. This myelination increases the speed of electrical impulse conduction along the nerve fiber. Schwann cells also aid in the regeneration of damaged peripheral nerves by guiding axonal growth.

C. Microglial cell: This cell functions as the resident macrophage and primary immune defense within the central nervous system. These small, mobile cells constantly scavenge for plaque, damaged neurons, and infectious agents to maintain neural health through phagocytosis.

D. Ependymal cells: Ependymal cells line the ventricles of the brain and the central canal of the spinal cord. These ciliated epithelial-like cells are responsible for the production, circulation, and monitoring of cerebrospinal fluid (CSF), creating a permeable barrier between the CSF and the nervous tissue. Their specialization is related to fluid dynamics and ventricular lining.

E. Oligodendrocyte: This is a specialized glial cell that extends multiple cytoplasmic processes to wrap around axons in the central nervous system. These wraps form the myelin sheath, a lipid-rich insulating layer that significantly increases the velocity of action potential conduction through saltatory conduction.

A. Parietal bone: The parietal bone makes up most of the superior and lateral aspects of the cranial vault. It connects with the frontal, temporal, and occipital bones via major sutures and protects the underlying cerebral cortex.

B. Mastoid process: The mastoid process is a large, rounded projection of the temporal bone located posterior and inferior to the external auditory meatus. It is a key landmark as the main attachment site for the sternocleidomastoid muscle and contains air cells that communicate with the middle ear cavity.

C. Styloid process: The styloid process of the temporal bone is a slender, pointed projection situated medial to the mastoid process. It serves as an attachment point for small muscles of the tongue and pharynx, and for the hyoid bone via the stylohyoid ligament.

D. Coronoid process: The coronoid process is a projection of the mandible extending upward from the anterior part of the mandibular ramus. It provides attachment for the temporalis muscle, which elevates the mandible during chewing, and does not articulate with other bones, contributing to mandibular movement and bite strength.

E. Zygomatic bone: The zygomatic bone is a paired facial bone forming the cheek prominence and part of the lateral orbital wall and floor. It articulates with the frontal, maxilla, temporal, and sphenoid bones, and serves as a site for attachment of muscles involved in facial expression and mastication.