Uterus - Anatomy & Physiology

BACK TO REPRODUCTIVE SYSTEM

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.