Prantner M M
Wisconsin Animal Health Laboratories, Madison 53705, USA.
Avian Dis. 1995 Jan-Mar;39(1):197-200.
Smooth muscle hyperplasia of the small intestine occurred in an 18-month-old rhea (Rhea americana). The mucosal thickening was 2-3 mm, and the enlarged muscle layers averaged 5 mm thick. The intestinal villi were lengthened, pleated, and expanded by smooth muscle hyperplasia within the lamina propria. The prominent muscularis mucosa averaged 20 smooth muscle cells thick. The tunica muscularis had symmetrical hyperplasia of both the inner circular muscle layer, which had an excess of 220 cells, and the outer longitudinal muscle layer, which consisted of five to six large fascicles, each approximately 75 cells thick. The smooth muscle hyperplasia, without hypertrophy, in all intestinal muscle layers differs greatly from mammalian cases of smooth muscle hypertrophy, in which the increase in intestinal size results from smooth muscle hypertrophy of the tunica muscularis.
一只18个月大的美洲鸵鸟（美洲鸵鸟属）出现了小肠平滑肌增生。黏膜增厚2 - 3毫米，增厚的肌层平均厚5毫米。肠绒毛因固有层内平滑肌增生而变长、呈褶状并扩张。显著的黏膜肌层平均由20层平滑肌细胞组成。肌层中，内环肌层对称增生，细胞数量超过220个，外纵肌层由五六个大束组成，每束约75个细胞厚。所有肠肌层的平滑肌增生而非肥大，这与哺乳动物平滑肌肥大的情况有很大不同，在哺乳动物中，肠道大小的增加是由于肌层平滑肌肥大所致。
