The Skull And Thoracic Limb Flashcards
The part of the skeleton within the head is the?
skull
skull protects the?
brain
skull supports many of the?
sense organs
skull forms passages for entry to the?
digestive and respiratory systems
Skull consist of cranial part called?
Braincase
braincase surrounds the?
brain, and the facial part
The skull is a very complex structure made mostly of what bones?
flat bones
All the bones of the skull are connected and fixed in place, except for the?
mandible
The mandible is unique because it’s attached to the skull with what joint?
movable joint( temporomandibular joint )
the bones of the skull are connected by interlocking joints called?
sutures
Suture joints are characterized by what apperance?
saw-toothed or serrated appearance
What is the function of suture?
keeps the bones attached with one another, but allows the cranium to expand and contract while remaining intact
Caudal and Dorsal Walls of skull contains:
- Occipital bone
- Parietal bone
- Interparietal bone
- Frontal bones
Lateral and Ventral Walls of skull contains:
- Temporal bones
- Sphenoid bone
- Ethmoid bone
The rostral wall of the skull contains which bone?
The ethmoid bone (unpaired).
Bome that contains the middle and inner ears
Temporal bone
This bone supports the brain and pituitary gland
Sphenoid bone
This bone presents numerous openings for passage of the olfactory nerves associated with the sense of smell
Ethmoid bone
Facial portion of the skull can be divided into 3 regions:
○ Orbit
○ Nasal
○ Oral
Portion of skull that means circle
Orbit
Orbit is surrounded by portions of what bones?
frontal, lacrimal and zygomatic bones
frontal, lacrimal and zygomatic bones participate in the formation of the?
zygomatic arch
zygomatic arch borders the?
ventral and caudal parts of the orbit
the bony arch forming the lateral wall of the orbit.
Zygomatic arch
Zygomatic arch consists of?
zygomatic bone and the zygomatic processes of the temporal bone
the depression in the medial margins of the orbit.
Lacrimal fossa
It collects tears and sends them through the lacrimal canal which opens into the nasal cavity
Lacrimal fossa
the rostral opening of the infraorbital canal, located in the maxillary bone
Infraorbital foramen
the paired structures lateral to the foramen magnum that articulates with the first cervical vertebra (atlas)
Occipital condyles
the ventral projection near the occipital condyles
Paracondylar (jugular) process
the large opening caudal to the zygomatic arch where the external ear attaches
External acoustic meatus
In life, External acoustic meatus is covered by?
ear drum
- located caudal to the external acoustic meatus
- It is an attachment site for muscles
Mastoid process
the caudal process of the occipital bone
External occipital protuberance
the transverse ridge at the transition from the dorsal to the caudal (nuchal) surfaces of the skull
Nuchal crest
the depression formed by the temporal and parietal bones
Temporal fossa
the rostral bony opening into the nasal cavity
Nasal aperture
extends rostrally from the external occipital protuberance on the midline (absent in ruminants)
Median sagittal crest
The large opening into the cranial cavity for continuity of the spinal cord and brain
Foramen magnum
the smooth bulbous enlargement on the ventral side of the temporal bone housing the middle ear
Tympanic bulla
The area on the zygomatic arch for articulation with the articular process (condyle) of the mandible
Mandibular fossa
the passageway for the optic nerve from the eyeball to the brain
Optic canal
It is rostral to many other foramina that allow passage of other cranial nerves
Optic canal
The two bony openings, at the caudal end of the hard palate, leading from the nasal cavity into the pharynx
Choanae or caudal nares
the horizontal parts of the incisive, palatine and maxillary bones, separating the nasal and oral cavities
Hard palate
the space in the cranium containing the brain, its meninges and blood vessels
Cranial cavity
the depression in the floor of the cranial cavity (sphenoid bone) holding the pituitary gland (hypophysis)
Hypophyseal fossa
the rostral part of the wall of the cranial cavity
Cribriform plate
Cribriform plate has many holes in the ethmoid bone allow the passage of the?
olfactory nerve
the hollow space behind the nose, surrounded by the facial bones
Nasal cavity
What divides the nasal cavity?
nasal septum
What bones are found inside each half of the nasal cavity?
ventral nasal conchae and ethmoturbinate bones
a scroll bone filling the rostral part of the nasal cavity
Ventral nasal concha
the largest nasal turbinate of the ethmoid bone
Dorsal nasal concha
the bone in the caudal nasal cavity
Ethmoid bone
Ethmoid bone has many bony scrolls called?
ethmoturbinates
Right and left nasal passages are separated longitudinally by what bone?
vomer bone and a cartilaginous and bony septum
arise from the lateral walls of the nasal cavity and project into the nasal passages
Scroll-like conchae (turbinate bones)
Covered with highly vascular mucous membrane that helps warm and humidify the inspired air
Conchae
Conchae on the caudal parts of the nasal cavity feature the ? , which contains the nerve cells specialized to detect odors
olfactory epithelium
the cavity (paranasal sinus) within the frontal bone
Frontal sinus
Largest and only mobile bone of the mammalian skull
Mandible
Mandible holds the lower teeth and consists of a right and left half united at the?
mandibular symphysis
the horizontal part bearing the lower incisor, canine, premolar and molar teeth of mandible
Body
the rostral opening of the mandibular canal
Mental foramen
the vertical part of the mandible bearing teeth
Ramus
the smooth process which articulates with the mandibular fossa of the temporal bone to form the temporomandibular joint
Articular (condylar) process
the opening on the medial side of the ramus leading into the mandibular canal
Mandibular foramen
- a bony framework that gives support to the pharynx (throat) and provides attachment to some pharyngeal, laryngeal, and lingual muscles
Hyoid apparatus
the unpaired hyoid bone
Basihyoid
articulates with the base of the skull at the petrus temporal. A paired bone
Stylohyoid
A paired hyoid bone next to stylohyoid and ceratohyoid bone
Epihyoid
A paired hyoid bone next to epihyoid, thyrohyoid and basihyoid bone
Ceratohyoid
articulates with the thyroid cartilage of the larynx. A paired hyoid bone
Thyrohyoid
○ Spine or backbone
○ Protects the spinal cord, supports the head and serves as attachment for the muscles affecting body movements
○ It extends from the skull through the tail and consists of irregular bones - vertebrae
○ The vertebrae are firmly joined by slightly moveable joints
○ All the vertebral joints together allow a great amount of movement
Vertebral column
○ The irregularly-shaped bones making up the spinal column
○ Each group is represented by its first letter followed by the number
representing how many are in each section
Vertebrae
Vertebrae are grouped by location into?
cervical (neck) , thoracic (cranial back) ,
lumbar (loin), sacral (croup) and caudal (tail) vertebrae
Canine vertebral formula:
C7 T13 L7 S3 Ca n
The number of each type of vertebrae is constant except the?
caudal ones
can be used as a rough estimate of the caudal vertebrae with some dogs having more and some less
Twenty
Common features of a typical vertebra are the?
body, vertebral arch, vertebral foramen and processes
○ The opening between vertebrae formed by caudal and cranial notches of adjacent vertebrae
○ These openings allow passage of the spinal nerves
Intervertebral foramen
the fibrocartilages connecting the bodies of adjacent vertebrae
Intervertebral discs
the space formed by the vertebral arch and the body
Vertebral foramen
of all the vertebrae form the vertebral canal, housing the spinal cord
vertebral foramina
formed in the live animal by all vertebral foramina
Vertebral canal
○ The dorsal part of a vertebra that arises from the body
○ It consists of two upright pedicles forming the walls of the vertebral foramen
○ From the pedicles, two lamina project to the midline and form the roof of the vertebral foramen
Vertebral arch
- the thick, spool-shaped ventral portion of the vertebra
- It is convex cranially and concave caudally to articulate with adjacent vertebrae
Body
The spine and the two transverse processes provide sites for?
muscle attachment
form synovial joints with adjacent vertebrae
4 articular processes (2 cranial; 2 caudal)