Axial Skeleton Flashcards
What bone is at number 2
cranial bones
what does the axial skeleton consist of?
the skull, mandible, hyoid apparatus, sternum, ribs, vertebral column
what does the head skeleton include?
- the skull (including mandible)
- bones of middle ear
- hyoid apparatus
What bone is at number 1?
facial bones
explain the facial region
- rostal
- houses nasal cavities, eyes, nose, tongue, structures of face
- carry upper dental arcade
- all paired except vomer
explain the neural region
- caudal
- houses the cranial cavity (brain case)
what skull morphology is this?
brachycephalic
what skull morphology is this?
mesaticephalic
what skull morphology is this?
dolichocephalic
what is the pink space?
cranial cavity
what is the yellow space
nasal cavity
what is the green space?
the paranasal sinuses
identify this marker
calvaria
identify this marker
- cribriform plate
- forms rostral wall of cranial cavity
- has tiny holes for passage of the olfactory nerves and blood vessels
what is nasal septum
septum that divides nasal cavity into two nasal fossae
what is this spot?
- nasal aperture
- bony opening into nasal cavity
- each nasal fossa extends from opening of aperture to the choanae
What is this?
- nasal choanae
- two bony openings at caudal end of hard palate and septum
- lead from nasal cavity into single nasopharynx
What are the paranasal sinuses?
air-filled spaces in facial bones (between external and internal layers), used to be spongy bone between compact bone, but spongy bone reabsorbs leaving space
Horse paranasal sinuses
- maxillary sinus is largest - 2 parts (rostral and caudal sinuses with bony septum between)
- 4 pairs: maxillary, frontal, conchal, sphenopalatine
Ox paranasal sinuses
- front sinus is the largest and extends into horn (cornual diverticulum)
- single maxillary sinus
- 6 pairs sinuses: frontal, maxillary, conchal, sphenoid, palatine, lacrimal
What is the vascular notch?
- notch present in horse, absent in carnivores and small ruminants
- can palpate pulse
What is at 1?
coronoid process
What is at 2?
condylar process
What is at 3?
- angular process
- only in dogs/cats
What is at 4?
- ramus
What is at 5?
- mental foramina
What is at 6?
- mandibular symphysis (joint)
- cartilage not fusion
What is at 7?
- body of mandible
What is the hyoid apparatus?
- a series of connected bones that suspends the tongue and larynx from the skull in intermandibular space
- articulates at the myeloid process
Lingual process
- projection of basihyoid bone into the tongue
- absent in carnivores
- long in horse
- short in ox
What is this structure and relevance?
- zygomatic arch
- palpable structure (widest part of skull)
- bridge between facial and neurocranial regions
What is number 1?
nasal bone
What is at number 3?
nasoincisive notch
What is at number 5?
infraorbital foramen
What is at number 2?
incisive bone
What animal does this skull belong to?
horse
What is the arrow pointing too and why is it significant?
- facial crest is a ridge on lateral surface of face, only present in horse can be used as landmark (along with nasoincisive notch) to find infraorbital foramen
What is at the astrik?
- facial tuberosity, in ruminants
- only rostral part from horse present
Orbit
- funnel shaped region that houses the eye
- rim is complete in horse and ruminants
- rim is incomplete in dog/cat has an orbital ligament to complete it
What is the red shaded region?
- pterygopalatine fossa
- a depression caudoventral to the orbit (also continuous with it)
- has many foramina for vessels/nerves
- filled by pterygoid muscles
- medial to zygomatic arch and mandible
What is the arrow pointing to?
- external acoustic meatus
- osseous opening into the tympanic bulla
- in intact state closed by tympanic membrane (eardrum)
- borders give attachment for cartilage of the ear canal
What does the arrow point at?
- located caudodorsal to the external acoustic meatus
- an attachment site for muscles
- hyoid apparatus articulates with