Bones - The Skull Flashcards
What are the two subdivisions of the Skull and what do they represent?
- Neurocranium: The bony box that surrounds the brain
- Viscerocranium: Skeleton of the face
What Bones can be seen from the Anterior View of the Skull and are they paired? (Mandible Removed) (4)
- Frontal Bone (unpaired bone)
- Maxilla (upper jaw: paired bone)
- Nasal Bones: nasal bridge where the two bones meet (paired bone)
- Zygomatic Bone: cheeks (paired bone)
What Cavities can be seen from an Anterior view of the Skull? (2)
- The Orbital Cavity
- The Nasal Cavity
What are the Openings visible in the Orbital Cavity from an Anterior view and what nerves pass through them? (3)
- The Superior Orbital Fissure (passage for Cranial Nerves III, IV, & VI)
- Optic Canal (passage for Cranial Nerve II)
- Inferior Orbital Fissure
What is visible in the Nasal Cavity from an Anterior view? (2)
Visible - Conchae (bony shelves) - Inferior Conchae - Middle Conchae Not Visible - Superior Conchae
Describe the Mandible
- Single bone (unpaired)
- Lower Jaw
- Part of the Skull but not the Cranium (cranium is the skull without the mandible)
Bones of the Skull visible from a Lateral view and are they single or paired? (8)
- Frontal Bone (single bone)
- Parietal Bone (paired bone)
- Occipital Bone (single bone)
- Lacrimal Bone (lacrimal duct passes through it to the nose)
- Temporal Bone (paired bone)
- Maxilla Bone (paired bone)
- Zygomatic Arch (union of temporal bone and zygomatic bone)
- Mandible
What Features of the Temporal Bone can be seen from a Lateral view? (3)
- External Auditory Meatus
- Mastoid Process
- Styloid Process
What Features of the Mandible can be seen from a Lateral view? (3)
- Ramus (body)
- Condylar (round shape): articulate with temporal bone in the temporomandibular joint (TMJ)
- Coronoid (triangular and sharp)
What Bones can be seen from the Posterior view of the Skull? (3)
- Parietal bones (paired)
- Occipital bone (the bump is called the External Occipital Protuberance)
- Sutural Bones (solid in adults)
What is the suture between the Occipital and Parietal Bone called?
Lambdoid Suture
What is the Suture called between the two Parietal Bones?
Sagittal Suture
What Bones are visible from a Superior view of the Skull? (3) and what is another name for the Superior view?
Bones Visible - Frontal Bone - Parietal Bone - Occipital Bone Other Name - Calvaria
What Sutures are visible from the Superior view of the Skull and what bones do they fuse together? (3)
Sutures
- Sagittal Suture: the two parietal bones
- Lambdoid (L-Shaped): between the occipital and parietal bones
- Coronal Suture: between the Frontal and Parietal bones
What is the name of the area where the Sagittal and Coronal Sutures meet? (in adults and in neonatal)
Adult
- Bregma
Neonate
- Anterior Fontanel (turns to bone at 12-18 months)
What is the name of the area where the Lambdoid and Sagittal Sutures meet in adults and in neonatal?
Adult
- Lambda
Neonate
- Posterior Fontanel (ossifies in 6 months)
What are the bones visible from an Inferior view of the Skull? (mandible Removed) (6)
Hard Palate - Maxillae - Palatine Other Bones - Sphenoid - Temporal - Occipital - Vomer (single bone)
What Bony Features are visible from an Inferior of the Skull? (Mandible Removed) (8)
- Choanae
- Pterygoid Process
- Occipital Condyles
- Zygomatic Arch
- Styloid Process
- Mastoid Process
- External Occipital Protuberance
- Median Palatine Suture
What are the 3 identifiable Fossa’s of the Skull from the Superior view of the Cranial Cavity?
- Anterior Cranial Fossa
- Middle Cranial Fossa
- Posterior Cranial Fossa
What Bones / Bony Features make up the Anterior Cranial Fossa? (5)
- Frontal Bone
- Sphenoid (lesser wing)
- Ethmoid Bone
- Cribriform Plate
- Crista Galli
What Bones / Bony Features make up the Middle Cranial Fossa? (2)
- Sphenoid (lesser and Greater Wings)
- Temporal Bone
What Bones / Bony Features make up the Posterior Cranial Fossa? (2)
- Temporal Bone
- Occipital Bone
What are the Major Openings in the Base of the Skull and what passes through them? (12) (sorry need to know these)
Cribriform Plate of Ethmoid (2 openings on either side) - Olfactory Foramina - Cranial Nerve I: Olfactory Nerve Hypophyseal Fossa (sella turcica) in the sphenoid bone - Pituitary gland (hypophysis) Optic Canal in Sphenoid Bone - Cranial Nerve II: Optic Nerve Superior Orbital Fissure - Cranial Nerves III, IV, & VI Foramen Rotundum - Second Branch of Cranial Nerve V Foramen Ovale - Third Branch of Cranial Nerve V Foramen Spinosum - Middle Meningeal Artery Foramen Lacerum - Sealed with a layer of cartilage Internal Acoustic Meatus - Cranial Nerve VIII Jugular Foramen - Internal Jugular Vein Hypoglossal Canal - Cranial Nerve XII Foramen Magnum - Spinal Cord
What is the Hardest Part of the Skull, what bone does it belong to, and where is it located? What does blood in the ear mean after a head injury?
Petrous
- Temporal Bone
- Embeds middle and inner ear
- Blood in-ear from head injury means the Petrous might be fractured
