Skull Bones and Vertebrae Notes

Skull Bones & Vertebrae

General Information

  • Chapter 4 of the textbook will be covered.
  • Skull information: Pages 76-78.
  • Older versions of the textbook are acceptable.
  • Anatomy is best learned in groups.
  • Saying, writing and hearing the words repeatedly is helpful.
  • Avoid self-doubt by writing down words and spelling them repeatedly, rather than just thinking about them.
  • When learning anatomy:
    • Look
    • Touch
    • Say
    • Write
    • Test each other

Bone Classification

  • Remember the bone classifications:
    • Long
    • Short
    • Pneumatic
    • Flat
    • Irregular
  • Apply the classifications to the bones.
  • Skull bones are mostly flat.
  • Vertebrae are irregular, having a combination of bone types.

Skull

  • Livestock have an extended rostral region.
  • The face and facial features of livestock will be very different than humans.
Bones of the Skull
  • Frontal Bone: Forehead.
  • Parietal Bone: Located back on cattle, up on the side for pigs.
  • Occipital Bone: Back of the skull, cranium.
  • Sutures: Squiggly lines indicating the border of one bone to another; adjoining and articulation.
  • Frontal Bone: Articulates with the nasal bone rostrally.
  • Maxilla: Upper jaw, ventral to the frontal bone.
  • Zygomatic: Cheekbone, caudal to the maxilla.
  • Lacrimal: Contains tear ducts.
    • Lacrimal Duct: Hole for tears; connects with the nasal cavity to drain tears. This is why your nose runs when you cry.
  • Zygomatic Arch: Articulation of the zygomatic and temporal bones. Also called the zygomatic temporal arch in older books.
  • Temporal Bone: Whole bone where the zygomatic arch is connected all.
  • Orbit: The foramen where the eye sits; made up of frontal, lacrimal, and zygomatic bones.
  • Occipital Condyles: Bony features of the occipital bone that articulate with the first vertebrae.
  • Palatine Bone: Maxilla articulates with the palatine bone on the dental surface.
  • Vomer Bone: Bone that the nasal septum attaches to, separating the right and left nasal cavities.
  • Nasal Conchae (Turbinate Bones): Scroll-like structures in the nasal cavity.
    • Thin and porous with many holes.
    • Highly vascularized--warms and humidifies air coming into the body.
    • Cools air escaping when breathing out.
  • Incisive Bone: Another dot found in livestock when studying the Maxilla and Nasal.
    • Absent in pigs (referred to as premaxillary).
  • Corneal Processes: Horns are extensions of the frontal bone.
  • Mandible: Lower jaw; no special features to know for this class.

Vertebrae

  • There is NO vertebrae named typical. The term 'typical' is used to describe features common to all different types of vertebrae. Understand the features that all vertebrae share, not the name.
Types of Vertebrae
  • Thoracic: Located in the thoracic cavity (lungs and heart) and articulates with ribs.
  • Lumbar: Looks like an airplane (as opposed to the thoracic vertebrae, which looks like one lacking wings). Supports the abdominal cavity.
  • Cervical: More square, boxy shape. They change from the skull all the way down to where they articulate the thoracic.
  • Sacral: All fused together.
  • Caudal: tail vertebrae.
Vertebrae Locations
  • Caudal (tail).
  • Sacrum.
  • Lumbar.
  • Thoracic.
  • Cervical (neck).
  • Do not need to know the number of bones in each section for this course.
Features of a Typical Vertebrae
  • Spinous Process: Located along the median plane. The bumps you feel when you run your fingers down your back.
  • Transverse Process: Lateral to the median, at a 90-degree angle.
  • Vertebral Foramen: Hole where the spinal cord travels through.
  • Vertebral Body
  • Vertebral Arch
  • Caudal: Looks like a spaceship. Has transverse processes that point ventrally.
Cervical Vertebrae 1 & 2
  • Always discussed specifically due to their unique shapes.
  • Vertebrae is the Atlas.
    • Looks like a butterfly or owl
    • Lacks a spinous process.
    • Has a nice transverse process.
    • Features: Body, vertebral foramen.
    • Smooth end articulates with the occipital condyles, allowing the head to move up and down (yes).
  • Cervical Vertebrae 2 is the Axis.
    • Has a spinous process and transverse processes which are more ventrally located.
    • Allows the animal's head to move