Gebärmutterwand-Struktur: Drei Myometrium-Schichten und ihre Funktionen

The uterine wall is thick due to three layers of smooth muscle (myometrium):

1. Inner (Submucosal) Layer: Longitudinal fibers; contracts during labor to help expel fetus.
2. Middle (Vascular) Layer: Thickest; interwoven circular/oblique fibers creating a lattice. Contracts in all directions, exerting equal pressure—critical for hemostasis postpartum and strong expulsive force.
3. Outer (Subserosal) Layer: Longitudinal fibers; works with inner layer to shorten uterus and push fetus downward during labor.

Estrogen/progesterone regulate myometrial growth and contractility. Oxytocin triggers coordinated contractions at term. The layered architecture enables both powerful expulsion and immediate postpartum compression of placental site vessels.