Blood Vessel Dissection Tips

Hemiazygous vein/coronary sinus structure – In the fetal pig, the hemiazygous vein drains directly into the coronary sinus of the heart. In fact, you could say that it becomes the coronary sinus. Consequently, the coronary sinus is relatively very large. The arrangement is different in humans. The reason for this difference is explained in the section comparing human and pig anatomy. See p. 55, 89 & 101 of the FPDG (Fetal Pig Dissection Guide).

Brachiocephalic vessels – Like humans, the fetal pig has two brachiocephalic (innominate) veins but only one brachiocephalic artery. The term brachiocephalic refers to the vessels’ connections to the arm and head. The term innominate means ‘nameless’! See p. 63 & 71 of the FPDG (Fetal Pig Dissection Guide).

Arm veins – The subclavian, subscapular and cephalic veins are not well described and illustrated in some lab manuals. In the fetal pig, they are all normally branches of the external jugular vein, in the order of: subclavian first, subscapular in the middle, and cephalic last (closest to the head). See p. 65 of the FPDG.

Hepatic portal system – With careful work, all of the major veins of the hepatic portal system can be dissected. Often, gastrosplenic and gastroduodenal branches can also be found. See p. 67 of the FPDG.

Illiac vessels – Like humans, fetal pigs have a pair of common illiac veins, but no common illiac arteries. See p. 69 & 79 of the FPDG.

Vertebral artery – Some lab manuals describe the vertebral artery as a branch of the costocervical trunk. While this is true in humans, in the fetal pig the vertebral artery is normally a branch of the subclavian artery, very close to the origin of the costocervical trunk. See p. 73 of the FPDG.

Internal iliac and umbilical arteries – Some books do not describe this clearly. The internal iliac arteries is a branch of the aorta. It runs deep into the pelvis. The umbilical arteries are branches of the internal iliac artery. Because the umbilical arteries are very large, the proximal part of the internal iliac arteries is also very large. The distal part (after the umbilical artery branch) of the internal iliac arteries is much smaller. After birth, the umbilical arteries are shut down, and the proximal part of the internal iliac artery then becomes similar in size to the more distal parts. See p. 79 of the FPDG.

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