Vertebrate Skull Flashcards
(46 cards)
Chondrocranium
From neural crest cells and mesenchyme - cartilagenous or replacement bone
Occipitals
Bones at the back of chondrocranium, surrounding foramen magnum
Sphenoids
Side bones of chondrocranium, surrounding foramina
Ethmoid complex
Honeycomb like structures, warms and filters air during inhalation through mucous and blood vessels, helps body retain heat and moisture during exhalation
Foramina
Openings on the side of chondrocranium for cranial nerves
Mesethmoid
Dividing structure between ethmoid complexes
Foramen magnum
Larger opening surrounded by occiptals in chondrocranium where the spinal cord exits the skull
Ethmoid complex synonym
Turbinals
Splanchnocranium
Seven branchial arches and all its variations, including jaws, middle ear bones, hyoid apparati. Made of cartilage or replacement one. Embryonic origins of neural crest cells.
Palatoquadrate
Splanchnocranium, modified mandibular arch, top “jaw”
Meckel’s cartilage
Splanchnocranium, modified mandibular arch, lower “jaw”
Quadrate
Reducted palatoquadrate, articulates with articular bone
Articular
Reduced ossified Meckel’s cartilage, articulates with quadrate
Dermatocranium
Dermal bone, only in teleostomi, covers the dorsal side and encases much of the splanchno- and chondrocranium
Hyomandibula
Splanchnocranium, modified hyoid arch, often for jaw suspension
Paleostyly
No jaws - agnathans. All seven arches are gill arches
Autostyly
Mandibular arch: palatoquadrate and Meckle’s, fused to chondrocranium
Hyoid arch: gill arch
Branchial arches: gill arhces
In holocephali and dipnoi
Amphistyly
P&MC attached by ligaments
Hyomandibula attached by ligaments
Others: gill arches
Extinct now, doesn’t exist any more
Hyostyly
Sharks
P&MC positioned by optic pegs
Hyomandibula forms swining bridge
Highly mobile
Modified Hyostyly
Most actinopterygii (teleost) fish
Quadrate and articular remain
Hyomandibula forms swining bridge, suspended also by sympletic
Highly highly kinetic, lots of joints and ligaments
Metautostyly
Amphibians, sauropsids
Q&A
Quadrate suspends lower jaw
Hyoid arch = middle ear columella
Craniostylic
Splanchnocranium all in middle ear
Jaw hinge is squamosal (top) and dentary (bottom)
Zygomatic arch
Bony feature at the side of the skull, forms from fusion of jugal and squamosal arch
Groups of the dermatocranium (6)
1) Facial (jaw, nose)
2) Orbital (eyes)
3) Temporal (behind orbit, posterior)
4) Vault (roof of skull)
5) Palatal (roof of mouth)
6) Mandibular (lower jaw)
