Download Skull part 41

Cranial Bones, continued…..
• Sphenoid bone
– Wedged between several other bones in anterior
portion of cranium
– Has a central portion and 2 wing-like structures
that extend laterally (???)
– Helps form base of cranium, sides of skull, and
sides of orbits (“eye sockets”)
– Midline of sphenoid bone has a depression (sella
turcica) that houses pituitary gland
– Contains 2 sphenoidal sinuses
Cranial Bones, continued…..
• Ethmoid bone
– Located in front of sphenoid bone
– Consists of 2 masses, one on each side of nasal cavity
• Masses joined by thin cribriform plates (???)
• Cribriform plates form part of nasal cavity roof.
– Crista galli – triangular process between cribriform
plates
– Perpendicular plate
• projects downward from cribriform plates
• helps form nasal septum
Cranial Bones, continued…..
• Ethmoid bone, continued…..
– Superior nasal concha and middle nasal concha project inward from lateral portions of ethmoid
bone toward perpendicular plate
– Lateral portions of ethmoid bone contain small
air spaces (ethmoidal sinuses)
Cranial Bones Diagrams
1. Whole class: Label cranial bones on the
diagrams of the skull.
2. Choose a color for each of the bones in the
cranium (EX: parietal bone = red).
3. Color the bones their assigned color in each
diagram.