Page 90 - Anatomy and Physiology of Farm Animals, 8th Edition

The Skeletal System / 75

bones are “pneumatized” as well (see (A)
Chapter 30).
VetBooks.ir well into other descriptive classifications.
Irregular bones are bones that do not fit

These include the vertebrae and some of
the unpaired bones of the skull; some anat-
omists include bones of the pelvis amongst
the irregular bones. The shapes of these
bones are specific to their locations.

Axial Skeleton

The axial skeleton includes bones on or
attached to the midline (axis) of the body (B)
and comprise the skull, vertebral column,
sternum, and ribs. Table 4‐2 lists the bones
of the axial skeleton by regions.

Skull

The part of the skeleton within the head is
the skull. It protects the brain, supports
many of the sense organs, and forms
passages for entry to the digestive and res-
piratory systems. The skull consists of the Figure 4-4. Lateral views of (A) porcine skull
cranial part (braincase), which surrounds and (B) ovine skull. Notice that the orbit of the pig
the brain, and the facial part (Figs. 4‐4, 4‐5, skull is incomplete caudally, whereas that of the
and 4‐6). The term cranium is sometimes sheep is complete.

Table 4-2. Bones of the Axial Skeleton

Skull
Cranial Part Facial Part Vertebrae Ribs Sternum
Paired: Incisive Cervical True (joined to Sternebrae
Frontal Lacrimal Thoracic sternum by cartilages) Manubrium
Parietal Mandible Lumbar Asternal (“false”) (not Xiphoid process
directly connected to
Temporal Maxilla Sacral sternum)
Unpaired: Palatine Caudal Floating (fixed only at
Ethmoid Pterygoid vertebrae; last 1 or 2
Interparietal Nasal pairs)
Occipital Turbinates
Sphenoid (conchae)
Vomer
Zygomatic
Hyoid
apparatus