Anatomy of Scapula of Horse
The scapula is a flat bone which is situated on the anterior part of the lateral wall of the
thorax; its long axis extends obliquely from the fourth thoracic spine to the sternal end of the
first rib. It is curved slightly and slopes outward in adaptation to the form of the thoracic wall. It
is triangular in outline, and has two surfaces, three borders, and three angles.
The Lateral Surface:
The lateral surface (Facies lateralis) is divided into two fossae by the spine of the
scapula (Spina scapulae), which extends from the vertebral border to the neck of the bone,
where it subsides. The free edge of the spine is thick, rough, and in great part subcutaneous. A
little above its middle there is a variable prominence, the tuber spines, to which the trapezius
muscle is attached. The supraspinous fossa is situated in front of the spine, and the
infraspinous fossa behind it. The former is much the smaller of the two; it is smooth and is
occupied by the supraspinatus muscle. The infraspinous fossa lodges the infraspinatus muscle;
it is wide and smooth in its upper part, narrower below, where it is marked by several rough
lines for muscular attachment; near the neck is the nutrient foramen, and a little lower is a
vascular groove.
The Costal Surface:
The costal surface is hollowed in its length by the subscapular fossa; this occupies
nearly the whole of the lower part of the surface, but is pointed above and separates two
rough triangular areas (Facies serrata), to which the serratus ventralis is attached. In the lower
third there is a vascular groove with several branches.
The Anterior Border:
The anterior border is convex and rough above, concave and smooth below.
The scapula is a flat bone which is situated on the anterior part of the lateral wall of the
thorax; its long axis extends obliquely from the fourth thoracic spine to the sternal end of the
first rib. It is curved slightly and slopes outward in adaptation to the form of the thoracic wall. It
is triangular in outline, and has two surfaces, three borders, and three angles.
The Lateral Surface:
The lateral surface (Facies lateralis) is divided into two fossae by the spine of the
scapula (Spina scapulae), which extends from the vertebral border to the neck of the bone,
where it subsides. The free edge of the spine is thick, rough, and in great part subcutaneous. A
little above its middle there is a variable prominence, the tuber spines, to which the trapezius
muscle is attached. The supraspinous fossa is situated in front of the spine, and the
infraspinous fossa behind it. The former is much the smaller of the two; it is smooth and is
occupied by the supraspinatus muscle. The infraspinous fossa lodges the infraspinatus muscle;
it is wide and smooth in its upper part, narrower below, where it is marked by several rough
lines for muscular attachment; near the neck is the nutrient foramen, and a little lower is a
vascular groove.
The Costal Surface:
The costal surface is hollowed in its length by the subscapular fossa; this occupies
nearly the whole of the lower part of the surface, but is pointed above and separates two
rough triangular areas (Facies serrata), to which the serratus ventralis is attached. In the lower
third there is a vascular groove with several branches.
The Anterior Border:
The anterior border is convex and rough above, concave and smooth below.
