Cranial Bones, continued

1
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

2
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

3
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)

4
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.