Lecture 21 - Skull and Cranial Nerves I Flashcards
What is the neurocranium?
Braincase
What is the function of the neurocranium?
Protect the brain
What is the facial skeleton called?
Splanchnocranium
What is the function of the splanchnocranium?
Face, sensory components, and masticatory apparatus
What are the three dorsal bones of the neurocranium?
Frontal, parietal, and the interparietal portion of the occipital
What is different about the frontal and parietal bone?
Both are bilaterally symmetrical
What is the function of the temporal fossa/line?
Contains the temporal muscle and fascia
What are the four ventral bones of the brain case?
Presphenoid, pterygoid, basisphenoid, and occipital
What canal is within the occipital bone?
Hypoglossal canal
What canals are within the basisphenoid bone?
Optic canal, Foramen rotundu, Foramen ovale, and Hypophyseal fossa
What are pterygoid processes?
Ventral projections of basisphenoid
What fossa are located within the temporal bone?
Mandibular fossa and stylomastoid foramen
What six bones line the brain cavity?
Occipital, parietal, frontal, petrous temporal, basisphenoidm and presphenoid
What does the neurocranium contain?
Cranial cavity
What are the two types of bone in the neurocraninal bones?
Compact and trabecular
What is compact bone?
Inner and outer tables, inner usually thiner
What is trabecular bone?
Between inner and outer tables of compact bone, contain red bone marrow
What is diploic bone?
Spongy bone between flat cranial bones
What are sutures in the skull made up of?
Sharpey’s fibers (type 1 collagen)
What do the sharpey’s fibers do?
Connect periosteum to the bone, provides strength and absorbs bone strain across suture
What happens when equines fall on their poll?
Basisphenoid fractures and avulsion of the longus capitus
Possible acute optic nerve damage
What are the three types of skull fractures?
Depressed - Linear - Comminuted
What is a depressed skull fracture?
Fragment of bone is depressed inward to compress or injure the brain
What is a linear fracture?
Usually occur at the point of impact, with fracture lines radiating away in two or more directions
What is a comminuted fracture?
Bone is broken into several pieces
What is the rostrum portion of the skull made up of?
Premaxilla, maxilla, palatine, nasal, lacrimal, and portions of the frontals and zygomatics
What is the hard palate made up of?
Premaxilla, maxilla, palatine, upper portion of “dental battery”
What is within the nasal choane?
Nasal conchae
What are nasal conchae?
Thin, scroll-like bones that are covered with repiratory and nasal epithelia
What makes up the bony orbit?
Zygomatic, lacrimal, frontal, maxilla, and palatine
What ligament is with in the orbit of the eye?
Postorbital ligament
What is the floor of the orbit formed by?
Processes of zygomatic, maxilla, and palatine
What is the zygomatic arch?
Formed via the temporal process of the zygomatic bone and the zygomatic process of the temporal bone
What muscle’s origin is the zygomatic arch?
Masseter muscle (ventral edge of the zygomatic arch)
What does the mandible articulate with?
Temporal, at the temporomandibular joint
What is within the mandible?
Lower dental battery
What foramen are within the mandible?
Mental foramina and mandibular foramen
What does CN I exit out of?
Cribiform plate
What does CN V1 exit out of?
Maxillary foramen
What does CN II exit out of?
Optic canal
What does CN XII exit out of?
Hypoglossal canal
What does CN IX, X, and XI exit out of?
Jugular foramen
What does CN VII and VIII exit out of?
Internal acoustic meatus
What does CN III, IV, and VI exit out of?
Orbital fissure
What does CN V2 exit out of?
Round foramen
What does CN V3 exit out of?
Oval foramen
