322 SITUATION OF THE INFERIOR VENA CAVA. 



Of the Inferior Vena Cava and the Veins which are con- 

 nected with it. 



This great vessel exceeds the Superior Cava in diameter. It 

 proceeds from the lower part of the right auricle, and very 

 soon perforates the diaphragm, at a small distance in front of 

 the spine, and rather to the right of the centre. As the peri- 

 cardium adheres to the diaphragm at this place, the vessel 

 appears to leave it abruptly. Immediately after leaving the 

 diaphragm, it proceeds along a groove in the posterior edge of 

 the liver, formed by the great lobe and the lobulus Spigelii.* 

 After leaving the liver it continues downwards, inclining back- 

 wards and to the left, and is soon in contact with the aorta, 

 which is on the left of it. It accompanies the aorta to its great 

 bifurcation, and divides in the same manner. It sends off, 

 during this course, branches to the diaphragm, liver, right 

 renal glands, the kidneys, and the testicles ; and also the lum- 

 bar and middle sacral veins. 



The Inferior Phrenic Veins 



Are thus denominated to distinguish them from other veins, 

 which are derived from the internal mammary, &;c. They 

 generally accompany the phrenic arteries, and are distributed 

 in the same manner. 



The Hepatic Veins 



Pass off from the vena cava, nearly at right angles, into the 

 substance of the liver, while this vein is in the groove of that 

 viscus, and before it has proceeded more than eight or ten lines 

 from the heart. 



They arise from the anterior part of the vena cava, and are 

 generally three in number. Sometimes there are two only, 

 but then one of them divides immediately after it enters the 

 substance of the gland. 



The distribution of these vessels in the liver has been 

 detailed in the account of that organ, and therefore need not 



* Sometimes it is completely surrounded by the liver. 



Ik. 



