Common Bone Features: Holes and
Depressed Areas
• _________
_________: A hole in
bone.
– Usually allow the passage
of nerve or blood vessel or
may exist simply to lighten
structure (pelvis)
• ______________: A
depressed or sunken area
on the surface of a bone.
– Usually occupied by
The Skeleton
• ______________ Skeleton = Bones
of head and trunk
– skull, hyoid bone, vertebrae, ribs,
sternum
• _______________ Skeleton =
Bones of limbs and appendages
– thoracic and pelvic limbs
• ______________ Skeleton = bones
formed in the soft organs.
Skull
• Consists of 37 or 38 separate bones joined by immovable
fibrous joints called ____________.
– exception: the ______________ is freely movable at is connected to
the rest of the skull by a synovial joint.
• Skull bones are divided into 3 regions:
– Bones of the ____________
– Bones of the ____________
– Bones of the ____________
• Within each region, there are external (visible) and
internal (hidden within the skull) bones
Bones of the Cranium
• Cranium -portion of skull that
surrounds the brain.
• External Bones of Cranium:
–
–
–
–
–
Frontal Bones (2)
Interparietal Bones (2)
Occipital Bone (1)
Parietal Bones (2)
Temporal Bones (2)
• Internal Bones of Cranium:
– Ethmoid Bone (1)
– Sphenoid Bone (1)
• Single bone that forms the
caudoventral portion or _________
of skull, most caudal skull bone.
• Importance:
– Is where spinal cord exits skull
• _______________ magnum
– Skull bone that articulates with first
cervical vertebrae (atlas).
• _____________ condyles are
articular surfaces on either side of
foramen magnum that come
together with the atlas to form the
atlantooccipital joint
Occipital Bone
Interparietal Bones
• Bone(s) located on dorsal __________ between occipital and
parietal bones
• Clearly visible in young animals, may fuse together in older
animals.
Parietal Bones
• Two bones that form the dorsolateral walls of the cranium
• Well developed in dogs, cats and humans, but relatively small
in horses and cattle.
• Two bones located ventral to the parietal bones
• Importance:
– Form walls of the cranium
– Contain middle and inner ear structures
– Form the temporomandibular joints with the ___________ (Lower jaw)
Temporal
Bones
Frontal Bones
• Forms ______________ region of skull
and a portion of the eye’s orbit.
• Located rostral to parietal bone.
• Frontal sinus is contained within
frontal bone.
• ____________ are extension of frontal
bone.
Internal (hidden) Bones of the Cranium
• Sphenoid Bone
– Forms____________ portion of the cranium and
contains the pituitary fossa, which houses the
____________ gland.
– Contains the sphenoidal sinus in most animals.
INTERNAL (hidden) BONES OF THE CRANIUM
• Ethmoid Bone
– Located rostral to sphenoid bone.
– Contains _____________ plate which has branches
of olfactory nerve passing through.
– Horses and humans also have ethmoidal sinus in
the ethmoid bone.
Bones of the Ear (Ossicles)
• Hidden in the middle ear from
the outside in:
– ____________-hammer
– ____________-anvil
– ____________-stirrup
• Function is to transmit vibrations
from the tympanic membrane
(eardrum) to cochlea where
vibrations are changed into nerve
impulses.
Bones of the Face
• External (landmark) Bones of the Face
–
–
–
–
–
–
Incisive (2)
Lacrimal (2)
Mandible (1 or 2)
Maxillary (2)
Nasal (2)
Zygomatic (2)
• Internal (hidden) Bones of the Face
–
–
–
–
Palantine (2)
Pterygoid (2)
Turbinates (4)
Vomer (1)
External Bones of the Face
• Incisive:
– Also called pre__________
bones
– Most ___________ skull
bones
– In common domestic
animals, this bone houses
upper incisor teeth.
(Ruminants have a dental
pad instead)
• Nasal:
– Forms the _________ of the
nose.
– Length depends on the
animal.
External Bones of the Face
• Maxillary
– Form the ________ jaw with
incisive bone
– House all teeth besides
incisors
– Forms rostral part of ________
palate
– contains maxillary sinus
• Lacrimal
– Two bones that form medial
portion of the ________ of the
eye.
– Contains lacrimal sac which is
part of tear system.
External Bones of the Face
• Zygomatic
– aka malar bones
– form portion of orbit
– join with temporal bone to form
zygomatic ______
• Mandible
–
–
–
–
–
lower jaw
houses all lower teeth
only __________ skull bone
forms TMJ with temporal bone
2 bones come together at
mandibular ________________
• fused into one bone in horses and
swine
– 2 parts: ramus and shaft
• Ramus = caudal, vertical part
• Shaft = contains teeth, horizontal
part
Internal Bones
of the Face
• ____________________ Bones:
– Make up caudal part of _____
palate
• ____________________ Bones:
– Support part of the lateral
walls of the ________ (throat).
• ____________________Bone:
– Forms part of nasal septum
(midline wall between left and
right nasal passages).
• _____________________:
– Also called nasal conchae.
– Thin and scroll-like that fill
most of nasal cavity space.