Friday, February 8, 2013

Cranial bones


1. FRONTAL BONE - forms the forehead and the roof of the bony sockets that contains the eyes

2. PARIETAL BONE - the two(2) bones (one on each side of the skull) that form the roof and upper part of the sides of the cranium

3. TEMPORAL BONE - the two bones that form the lower sides and base of the cranium. each bone encloses an ear and contains a fossa for joining with the mandible (lower jaw bone). The temporomandibular joint (tmj) is the area of connection between the temporal and mandibular bones. The mastoid process is a round (mast/o means breast) process of the temporal bone behind the ear. The styloid process (styl/o means pole or stake) projects downward from the temporal bone.

4. OCCIPITAL BONE - forms the back and base of the skull and joins the parietal and temporal bones, forming a suture. the inferior portion of the occipital bone has an opening called the foramen magnum through which the spinal cord passes.

5. SPHENOID BONE - the bat-shaped bone that extends behind the eyes and forms part of the base of the skull. Because it joins with the frontal, occipital, and ethmoid bones bones, it serves as an anchor to hold those skull bones together (sphen/o means wedge). The sella turcica (meaning Turkish saddle) is a depression in the sphenoid bone in which the pituary gland is located.

6. ETHMOID BONE - the thin, delicate bone that supports the nasal cavity and forms part of the orbits of the eyes. It is composed primarily of spongy, cancellous bone, which contains numerous small holes (ethm/o means sieve)

picture from