AXATOMY IN A NUTSHELL. 



33 



LESSON VI. 



In the fetal heart the Eusatchian valve is large. The foramen ovale 



which joins the two auricles gives a free communication between them until 

 the middle of fetal life, at which time a valve grows from the posterior wall of 

 the right auricle to the left of the foramen ovale, and prevents the blood from 

 passing through except from right to left. In twenty per cenl of the cases the 

 foramen ovale remains open throughout life. (Plate IX.) 



PLATE VII. 



PHALANGES. TWO 

 CENTERS FOR EACH BONE. ONE FOR SHAFT. ONE FOR ( £ 

 METACARPAL EXTREMITY. 



APPEAR BETWEEN THE 

 THIRD AND FIFTH YEAR 

 CONSOLIDATE IN THE 

 EIGHTEENTH YEAR. 



APPEAR IN THE THIRD 



CONSOLIDATE IN THE 

 TWENTIETH YEAR 



METACARPUS 

 TWO CENTERS FOR EACH BC 

 ONE FOR SHAFT. ONE FOR 

 DIGITAL EXTREMITY EXCEPT FIRST 



CARPUS. 

 ONE CENTER FOR EACH BONE 

 ALL CARTILAGINOUS AT BIRTH 



APPEARS IN THE THIRD YEAR. 



CONSOLIDATES IN THE ' 



TWENTIETH YEAR. 



Nutrient Arteries of Hoxk.s ok 1Iwi>. 



The ductus arteriosus which is aboul half an inch long joins the de- 

 scending aorta just below the origin of the lefl subclavian artery. 



It arises from the left pulmonary artery at first from the common pul- 

 monary. 



The hypogastric or umbilical arteries arise from the internal iliac, and 

 after passing beside the bladder go through the umbilicus to the placenta 

 a 



