_i_, Radial artery; _j_, ulnar artery; _k_, volar interosseous artery;
_l_, deep volar arch; _m_, external (fifth) volar metacarpal artery;
_n_, deep volar metacarpal arteries; _p_, superficial volar
metacarpal arteries; _o_, _q_, common digital arteries; _r_, proper
digital arteries.
]
The rete carpi dorsale gives off four =dorsal metacarpal arteries= which
descend in the intermetacarpal spaces and unite near the
metacarpo-phalangeal joints with the volar arteries to form the common
digitals.
The =thoracic aorta= supplies the last nine or ten pairs of intercostal
arteries, but no anterior phrenic arteries. It gives off two or more
œsophageal branches, in addition to the broncho-œsophageal, which arises
close to or with the sixth intercostal and ramifies in the usual manner.
The =abdominal aorta=, after giving off the external iliac arteries,
continues about half an inch to an inch (ca. 1 to 3 cm.) under the last
lumbar vertebræ, gives off the internal iliacs, and is continued by the
middle sacral artery. This small vessel runs backward under the sacrum
and coccygeal vertebræ and gives off branches in segmental fashion.
[Illustration:
FIG. 491.—END BRANCHES OF AORTA AND RADICLES OF POSTERIOR VENA CAVA OF
DOG.
_a_, Abdominal aorta; _b_, posterior mesenteric artery; _c_, lumbar
arteries; _d_, circumflex iliac artery; _e_, external iliac artery;
_f_, deep femoral artery; _g_, posterior abdominal artery; _h_,
external pudic artery; _a_, femoral artery; _i_, _i_, internal iliac
arteries; _k_, visceral branch of _i_; l, parietal branch of _i_;
_m_, ilio-lumbar artery; _n_, anterior gluteal artery; _o_, lateral
coccygeal artery, _p_, posterior gluteal artery; _q_, umbilical
artery; _r_, middle hæmorrhoidal artery; β, posterior hæmorrhoidal
artery; _s_, perineal artery; _t_, art. profunda penis; _n_, art.
bulbi urethræ, _v_, art. dorsalis penis; _w_, middle sacral artery,
_a′_, posterior vena cava; other veins are satellites of arteries
and correspondingly named; _1_, ilio-psoas muscle; _2_, tendon of
psoas minor; _3_, abdominal muscles; _4_, sartorius; _5_, rectus
femoris; _5′_, vastus internus; _6_, pectineus; _6′_, adductor; _7_,
gracilis; _8_, symphysis pelvis; _9_, ilium; _10_, pyriformis; _11_,
gluteus superficialis; _12_, obturator internus; _13_, penis; _14_,
lumbar vertebræ. (After Ellenberger, in Leisering’s Atlas.)
]
The =cœliac artery= gives off the hepatic artery and forms a short
=gastro-splenic= trunk. The hepatic artery gives off several hepatic
branches, and the pyloric or right gastric artery, which passes along
the lesser curvature of the stomach, anastomoses with the (left)
=gastric artery=, and is continued by the gastro-duodenal. This divides
near the pylorus into right gastro-epiploic and pancreatico-duodenal.
The (left) gastric artery passes to the lesser curvature of the stomach
and ramifies chiefly on the left part of the stomach, giving off a
branch which anastomoses with the pyloric branch of the hepatic. The
=splenic artery= gives off pancreatic branches, and reaches the lower
part of the spleen. It gives off the left gastro-epiploic, and a branch
which passes to the dorsal end of the spleen, which it supplies, besides
giving off twigs to the left extremity of the stomach.
The =anterior mesenteric artery= arises close behind the cœliac. It
gives off a common trunk for two colic arteries and the ileo-cæco-colic.
The former supply the transverse and the anterior part of the left or
descending colon, while the latter divides into branches for the ileum,
cæcum, and first part of the colon. The trunk is continued as the artery
of the small intestine, giving off fourteen to sixteen branches (Aa.
jejunales), which form a series of anastomotic arches in the mesentery
near the bowel.
Two =phrenico-abdominal arteries= (Aa. phrenicæ caudales) come off from
the aorta behind the anterior mesenteric, and divide into phrenic and
abdominal branches. Each phrenic artery diverges from its fellow in
descending on the abdominal surface of the corresponding crus of the
diaphragm to the sternal part. The inner branches anastomose with those
of the opposite artery, the outer branches with intercostal arteries
chiefly. The abdominal arteries give branches to the lumbar muscles, the
renal fat and capsules, and ramify in the oblique abdominal muscles.
The =renal= and =spermatic arteries= offer no special features.
The =utero-ovarian artery= divides near the ovary into three or four
branches which supply the ovary and uterus, anastomosing with the
uterine artery.
The =posterior mesenteric artery= is small. It divides into two branches
which supply the terminal part of the colon and the anterior part of the
rectum.
The =circumflex iliac artery= usually arises from the terminal part of
the aorta.
The =external iliac artery= usually gives off no collateral branches.
[Illustration: