(_a_) Two lingual arteries having a common point of origin near the
carotid gland.
(_b_) A carotid artery passing to the head. At its origin it is
slightly swollen into the carotid gland.
2. Trace the systemic arches which run backwards on each side of the
body, meeting posteriorly to form the dorsal aorta. Each systemic
arch gives rise to an artery which branches into:--
(i) A scapular artery to the pectoral girdle.
(ii) A cutaneous artery to the skin.
(iii) A brachial artery to the arm.
Trace the dorsal aorta backwards, and note that it gives rise to the
cœliaco-mesenteric artery about midway between its origin and the
origin of the first pair of renal arteries. The dorsal aorta then
passes between the kidneys giving four renal arteries to each, and
proceeds backwards and divides into an internal iliac artery to each
leg. This artery lies between the femoral and the sciatic veins. From
each of these arteries a branch is given off which divides into:
(i) An iliac artery to the muscles around the ilium.
(ii) A cutaneous artery to the skin of the body, just anterior to
the leg.
(iii) A small artery to the anterior dorsal surface of the hind
limb.