7. The Adult Uterine Tubes (oviduct, Fallopian Tube, or Salpinx)

  1. Introduction: the uterine tubes are paired structures about 10-15 cm long and 6-8 mm in diameter. One end opens into the peritoneal cavity near the ovary; the other end opens into the superior lateral part of the uterine cavity. The tube conducts the ova, discharged at ovulation, to the uterine cavity
  2. Regions of the tube
    1. INFUNDIBULUM: funnel-shaped, formed of a number of processes or fimbriae
    2. AMPULLA: largest segment, thin-walled like the infundibulum
    3. ISTHMUS: short segment, smaller in diameter and thicker walled than the ampulla
    4. UTERINE OR INTERSTITIAL: segment embedded in uterine wall. Of small diameter (1 mm)
  3. Histology of uterine tube: wall consists of a series of layers
    1. MUCOSA: simple columnar type epithelium with some ciliated cells and others being narrow, peg-shaped, and nonciliated
      1. Secretes mucus and other substances to maintain ovum's journey through tube
      2. Epithelial height and proportion of ciliated to nonciliated secretory cells vary and correlate with menstrual cycle changes; , epithelium is taller in the first half of the follicular phase than second half, and the relative number of nonciliated cells increases in the corpus luteum phas In addition, the epithelium is low in pregnancy and the number of "peg" cells increases
      3. Cilia of the epithelium beat toward the uterus
      4. There are no glands in the tube
      5. The mucosa of the infundibulum and ampulla have many tall folds with corresponding deep grooves. The lumen is irregular. The folds decrease in height toward the uterus and are low in the isthmus. The uterine portion of the tube has slight folds
    2. MUSCULARIS: thickest in the isthmus and thins toward the fimbriated end
      1. Has a well-developed inner circular layer and a thin outer longitudinal layer (the latter is complete only in the isthmus)
      2. The longitudinal muscle bundles are discontinuous in ampulla and may be absent in the fimbria
    3. SEROSA has the usual structure of peritoneum
  4. Blood supply: tubal branch of the uterine artery and small branches from the ovarian artery. The arteries run in the stroma along the bases of the folds, giving rise to a dense capillary stromal network
      1. The veins course similar to the arteries
  5. Nerve supply: via the ovarian plexus and fibers from the inferior hypogastric plexus. Some fibers are sensory, others are autonomic to muscle coats, and still others are vasomotor to the blood vessels
  6. Lymphatic drainage: lymphatics follow the blood vessels and drain into the lumbar (or aortic) nodes

the adult uterine tubes  (oviduct, fallopian tube, or salpinx): image #1