A few bones of the skull are frequently studied as separate bones. The sphenoid bone has a superficial resemblance to a bat or butterfly. There are the lesser wings, the greater wings, and the pterygoid plates, all of which resemble wings. The dorsum sellae is the posterior part of the sella turcica (a depression that holds the pituitary gland). Locate the foramen rotundum and the foramen ovale on the sphenoid bone. These holes enclose parts of the trigeminal nerve.
The temporal bone has a flat squamous portion and a denser petrous portion. The section of the temporal bone that connects to the zygomatic bone is the zygomatic process. There are two significant canals or meatuses for hearing. These are the external acoustic meatus and the internal acoustic meatus. The mastoid process is a large bump that can be palpated directly posterior to the ear. The styloid process anchors a number of small muscles.
The ethmoid bone is located just posterior to the nose and is best seen isolated from the rest of the skull bones. The cribriform plate that has small holes called olfactory foramina in it. Locate the crista galli and the perpendicular plate. The ethmoid has four curved structures lateral to the perpendicular plate. These are the two superior nasal conchae and the two middle nasal conchae. The ethmoid sinuses are numerous small holes in the bone. Locate the structures of these skull bones. Label the illustration and color in the features of the bones.
(Sphenoid features), a. Sella turcica, b. Lesser wing, c. Foramen rotundum, d. Foramen ovale, e. Dorsum sellae, f. Greater wing
(Temporal features), g. Squamous portion, h. Zygomatic process, i. External acoustic meatus, j. Styloid process, k. Mastoid process
(Ethmoid features), I. Crista galli, m. Middle nasal concha, n. Perpendicular plate, o. Superior nasal concha
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.