Cullen W C, Fletcher T F, Bradley W E
Anat Rec. 1981 Feb;199(2):177-86. doi: 10.1002/ar.1091990203.
Urinary bladders and urethrae were collected from six adult and two juvenile female dogs. Five urethral regions and the neck and body of the bladder were sampled. Volume fractions for connective tissue including elastic fibers, smooth and striated muscle, and epithelium were obtained by projecting section images onto an array of points and computing the number of points overlying a tissue constituent per total points overlying the tissue section. Smooth muscle occupied approximately half the volume of the bladder wall, one-third the volume of the vesical neck, and one-fourth the volume of the proximal urethra. Striated muscle was present in the distal half of the urethra, where the total muscle coat occupied about one-third of the urethral wall volume. Smooth muscle was practically absent in the terminal urethra, where the striated urethralis muscle encircles urethra and vagina in common. Epithelial area and lumen perimeter were not significantly different along the length of the urethra except that urethral epithelium was significantly thicker adjacent to the vesical neck. In terms of histological proportions, the vesical neck was intermediate between the body of the bladder and the proximal urethra.
从六只成年雌性犬和两只幼年雌性犬身上采集膀胱和尿道。对五个尿道区域以及膀胱颈部和体部进行采样。通过将切片图像投影到一系列点上，并计算覆盖组织成分的点数占覆盖组织切片的总点数的比例，得出包括弹性纤维、平滑肌和横纹肌以及上皮组织在内的结缔组织的体积分数。平滑肌约占膀胱壁体积的一半、膀胱颈部体积的三分之一以及近端尿道体积的四分之一。横纹肌存在于尿道的后半段，此处总的肌层约占尿道壁体积的三分之一。在尿道末端，平滑肌实际上不存在，此处横纹肌尿道肌共同环绕尿道和阴道。除膀胱颈部附近的尿道上皮明显更厚外，沿尿道长度的上皮面积和管腔周长无显著差异。就组织学比例而言，膀胱颈部介于膀胱体部和近端尿道之间。
