Uterus - Anatomy & Physiology

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BACK TO REPRODUCTIVE SYSTEM

Introduction

Structure

Function

  • Provides a suitable environment for embryo development and attachment.
  • In response to increasing amounts of oxytocin production by the corpus luteum during the luteal phase the endometrium produces luteolytic PGF2a to cause degeneration of the corpus luteum.
  • The uterus contributes varying amounts of maternal tissues towards the placenta.
  • The myometrium is involved with sperm transport through the uterus towards the oviduct.
  • Contrations of the myometrium during parturition is important for feotus and placenta expulsion.

Anatomical Location & Boundaries

The Uterus body and Uterine horns are located within the abdominal cavity dorsal to the Intestinal mass. -broad ligament?

Histology

The appearance of the uterus varies with the stages of the oestrus cycle. Follicular phase

  • Increasing numbers of uterine glands developing and elongating within the endometrium due to the influence of Oestrogens produced by the developing follicles.
  • General increase in the thickness of the endometrium.
  • The epithelium lining the glands is Simple Columna epithelium.

Luteal phase

  • The endometrium is at its maximum thickness with a large number of highly developed glands.
  • This is the secretory phase for the endometrium.

Anoestrus

  • The endothelium is relatively thin and there is little proliferation or gland development.
  • The glands are lined by Simple Cuboidal epithelium.

Innervation

The uterus is innervated by both Sypathetic and Parasympathetic fibres which play a part in the regulation of uterine activity. This is highlighted by Iatrogenic manipulation of parturition using β-Adrenoreceptor Agonists for delaying parturition and Antagonists for inducing parturition. However, uterine activity and normal parturition can be acheived when these nerves are severed.

Vasculature

  • Uterine branch of the Ovarian artery supplies the cranial parts of the Uterine horns.
  • Uterine artery supplies the rest of the uterine horns and the uterine body. This is a branch off the Internal Iliac artery in most domestic species, except the Mare where insted it is a branch off the External Iliac artery. The Uterine artery and the Ovarian artery anastomose within the Broad ligament.

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