初生儿消化系統的解剖特征

THE ANATOMICAL FEATURES OF THE DIGESTIVE SYSTEM OF THE NEW-BORN INFANTS

本文根据对126个初生儿消化系各器官的观察,对其特征作了闡述。一、口腔虽然未有牙齿,但上下齿槽突明显可見,口腔仍可分为口腔前庭和固有口腔两部分。硬腭前部有明显的横襞。舌較长,舌尖位于口腔前庭。二、咽咽下界如以喉下界为标准一般相当于第4、5頸椎之間。三、食管食管全长不能看到有較狹窄部。全长約8—10厘米,約为身长的1/5—1/6,寬度約5—8毫米,但下段1.5厘米长处稍膨大,約为9毫米。从上頜齿槽突到賁门的距离为13—16厘米。平均約为15厘米。四、胃初生儿的胃底、大弯、小弯的发育明显,已具备了成人胃的固有形态。大多数胃呈"J"形胃,相当于X光象上所見的袜形胃。整个胃为肝左叶所遮盖,胃体略呈垂直位,幽門部略呈水平位或弯曲上升。賁門位正中綫左側,相当于第9或10胸椎高度,幽门位正中綫上,相当于第12胸椎或第1腰椎高度。五、肝肝較大,約为体重的3—4%,肝占据腹腔中較大的位置(約为右上方1/3)。其前緣在肋弓下2—4厘米。臍靜脉未閉塞,几位正中綫上。本文詳細观察了臍靜脉在肝下面的經过及其分枝,这是文献上尚未詳細提到的。六、胰重約3—5克,横越左侧腎上腺前面。七、腸管十二指腸内壁多数具有2个乳头。系膜小腸外观不呈圓管状,而是互相压扁呈不規則的表面。盲腸均呈漏斗形,位于侧腹部,髂嵴的上方,右腎下端的外側,在126例标本中,发現3例高位盲腸,占2.4%。蚓突长約3—5厘米,蚓突口无粘膜瓣,胎囊或多或少进入蚓突内。蚓突位置有各种各样。結腸虽可見結腸带,但在絕大多数标本没有袋状結构,沒有脂垂。乙状結腸和降結腸内集結了大量胎粪,因而胀大。八、腹膜网膜和腸系膜内无肉眼可見的脂肪沉着,因而透明,大网膜很短,从胃大弯下垂約2—3厘米,只遮盖住横結腸左段,小腸則沒有大网膜遮盖。

The anatomical features of the digestive system in 126 new-born cadavers were examined.In the oral cavity,the palatal ridges on the anterior part of the hard palate were very conspicous.The tongue,in most of the cases,was found to protrude out into the vestibule.This condition was contradictory to most of the textbooks,which state the tongue of the new born infant is short.The pharynx showed usual appearance as in the adult.Its lower end,taking the level of the lower border of the larynx as a land-mark,was at the level of the 4th or 5th cervical vertebra.The distance between the lower margin of the soft palate to the above mentioned level was 3—4 cm.The oesophagus showed no distinct constriction throughout its length.The distance between the upper alveolar process to the cardiac orifice of the stomach was 13—16 cm.,being 15 cm.in average.In the majority of cases,the stomach assumed a"J"shape,and its general outline was very much like that of the adult.The liver was relatively large,its weight being 3—4%of that of the body.The umbilical vein when coursing in the left longitudinal fissure of the liver showed a dilation,from which 2—3 branches were given out to the left lobe;1 or 2 branches to the caudate lobe;1 to the right lobe after anastomosing with the portal vein.From this anastomotic branch,1 twig was given to the quadrate lobe.The termination of this vein then became the ductus venosus,much diminished in size,before joining the inferior vena cava.The pancreas was 3—5 gms.in weight.Its course was in front of the left suprarenal gland instead of the left kidney.The small intestine appeared lengthy.No measurement was made on account of the embalmed bodies.A second duodenal papilla was found in 86%of the total cases.The caecum assumed a funnel-shape,lying above the iliac crest in most of the cases.In 3 cases the caecum was observed to be high up under the liver.The vermiform appendix was 3—5 cm.in length,and no valve was found at its orifice.A certain quantity of meconium was found in the lumen of the appendix.The position of the appendix was found to be variable.The taeniae coli were visible.In the majority of cases,neither sacculations nor ap-pendices epiploicae were present.The descending and sigmoid colon were largely distended by the meconium.No visible fat deposition was found in the omentum and mesentery in which the blood vessels and lymph nodes were clearly visible.The great omentum was rather short and extended only 2—3 cm.downwards from the great curvature of the stomach.