THE BLOOD VESSELS 
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3. The blood vessels of the thoracic cavity which comprise in , 
addition to branches of the anterior vena cava and the aorta, the 
entire pulmonary system of arteries (injected blue) and veins 
(injected red). 
4. The hepatic portal system and the mesenteric arteries. 
5. The branches of the posterior vena cava and the remaining 
branches of the aorta. 
List of the principal blood vessels to be identified: 
1. Systemic System. 
(a) Arteries (injected red). 
Aorta, leading from left ventricle and forming an arch from 
which the anterior branches are given off. 
i. Anterior branches: 
Brachiocephalic. 
Right subclavian. 
Right carotid. 
Left carotid. (This, in some species, e.g., cat, 
guinea pig, is a branch of the brachiocephalic.) 
Left subclavian. 
ii. Thoracic branches: 
Intercostals (several pairs). 
iii. Abdominal branches: 
Phrenic. 
Coeliac axis. 
Hepatic. 
Coronary ( i.e ., to the stomach). 
Splenic. 
Superior mesenteric (in some species, e.g., guinea 
pig, this is united with the coeliac axis). 
Suprarenals (paired). 
Renals (paired). 
Spermatic or ovarian (paired). 
Inferior mesenteric. 
Lumbar (in segmentally arranged pairs). 
Iliolumbars. 
Common iliacs (in some species, e.g., cat, there is no 
common iliac, the external and internal iliacs being 
given off from the aorta as separate branches). 
