| Term 
 | Definition 
 
        | posterior surface, aka fundus |  | 
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        | Term 
 | Definition 
 
        | most anterior midline point of superior surface |  | 
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        | Term 
 | Definition 
 
        | lowest region of the bladder, most fixed part due to ligaments tethering to posterior aspect of pubic bones |  | 
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        | Term 
 | Definition 
 
        | insertion of a needle into the interior of the bladder from the suprapubic anterior abdominal wall, peritoneum is lifting onto the bladder's superior surface --> bladder is in direct contact with anterior abdominal wall |  | 
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        | Term 
 
        | ureter entrance into the bladder |  | Definition 
 
        | pierce bladder wall at upper lateral corners of superior surface, only open temporarily into the bladder with peristaltic waves to force urine into the bladder |  | 
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        | Term 
 | Definition 
 
        | triangular, posterior area of the inner surface of the bladder, fold-free, top two corners are ureters, bottom corner is the neck of the bladder |  | 
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        | Term 
 | Definition 
 
        | the smooth muscle tissue of the wall of the bladder |  | 
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        | Term 
 
        | internal sphincter of bladder |  | Definition 
 
        | formed by circumferentially-oriented smooth muscle fibers, involuntary, inhibited by pelvic splanchic nerves, motor innervation by lumbar splanchic nerves |  | 
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        | Term 
 | Definition 
 
        | small branches of anterior rami of S2, S3, S4 that transmit pregangionic parasympathetic fibers to detrusor and internal sphincter of bladder |  | 
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        | Term 
 | Definition 
 
        | arise from lumbar ganglia of sympathetic trunk, transmit preganglionic sympathetic fibers to internal sphincter |  | 
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        | Term 
 
        | superior, middle, and inferior rectal folds |  | Definition 
 
        | transverse crescentic folds which mark the upper margin of each lateral curvature of the rectum |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | lower part of the rectum that is more dilated and distensible than the upper part, upper margin marked by the middle rectal valve |  | 
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        | Term 
 | Definition 
 
        | a thick circular layer of smooth muscle fibers in the wall of the upper two-thirds of the anal canal |  | 
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        | Term 
 
        | intermuscular (intersphincteric) groove |  | Definition 
 
        | the sharply defined lower border of the internal anal sphincter palpable upon digital examination of the anal canal |  | 
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        | Term 
 | Definition 
 
        | a thick layer of skeletal muscle fibers which surrounds the entire anal canal |  | 
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        | Term 
 
        | puborectalis part of levator ani |  | Definition 
 
        | forms a u-shaped muscular sling around the posterior and lateral surfaces of the anorectal junction, tonic contraction draws the anorectal junction forward, preventing unwanted passage of feces |  | 
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        | Term 
 | Definition 
 
        | interdigitation of puborectalis muscles and muscles from deepest part of external anal sphincter at the upper margin of the anal canal, palpable on digital examination |  | 
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        | Term 
 | Definition 
 
        | longitudinal folds in the mucosal lining of the anal canal, caused by the internal rectal venous plexus |  | 
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        | Term 
 | Definition 
 
        | recesses formed by anal valves at the base of the space between two adjacent anal columns |  | 
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        | Term 
 | Definition 
 
        | short, transverse folds of mucosal lining that extend between the lower ends of the adjacent anal columns |  | 
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        | Term 
 
        | drainage of blood from superior rectal vein |  | Definition 
 | 
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        | Term 
 
        | drainage of blood from inferior rectal veins |  | Definition 
 | 
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        | Term 
 | Definition 
 
        | varicosities of the internal rectal venous plexus in the upper half of the anal canal, lined by rectal epithelium |  | 
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        | Term 
 | Definition 
 
        | varicosities of the external rectal venous plexus in the lower half of the anal canal, lined by skin |  | 
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