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Guilherme Mazui

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What is the Difference Between Endometrium and Myometrium?

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The endometrium and myometrium are two distinct layers of the uterus that serve different functions. Here are the main differences between them:

  • Location: The endometrium is the inner layer that lines the uterus, while the myometrium is the middle and thickest layer of the uterus wall.
  • Structure: The endometrium is composed of columnar epithelium and is highly vascular, with numerous tubular glands supported by a thick vascular stroma. In contrast, the myometrium is made up mostly of smooth muscle, organized into poorly-defined layers with bundles of fibers interwoven in varying directions.
  • Function: The endometrium provides optimum environmental conditions for the implantation of the blastocyst and undergoes extensive changes during the menstrual cycle. It is functionally subdivided into two layers: the stratum functionalis, which is a thick superficial layer that is sloughed off during menstruation, and the stratum basalis, which supports the glands and stroma. The myometrium, on the other hand, is involved in facilitating uterine movements.

In summary, the endometrium is the inner layer of the uterus that provides a suitable environment for the implantation of a fertilized egg and undergoes significant changes during the menstrual cycle, while the myometrium is the middle, thickest layer of the uterus wall made up of smooth muscle that plays a role in uterine movements.

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  • What is the Difference Between Endometrium and Myometrium?
  • Comparative Table: Endometrium vs Myometrium

    • Comparative Table: Endometrium vs Myometrium

    The endometrium and myometrium are two distinct layers of the uterus. Here is a table highlighting the differences between them:

    Feature Endometrium Myometrium
    Definition The endometrium is the innermost layer of the uterus, consisting of glandular and stromal tissues. The myometrium is the middle layer of the uterus, composed of smooth muscle tissue.
    Function The endometrium plays a crucial role in menstruation and pregnancy, providing a suitable environment for the implantation of a fertilized egg. The myometrium provides structural support and muscle contraction during labor.
    Histology The endometrium is primarily made up of epithelial cells, including glandular and ciliated cells, and supporting stromal cells. The myometrium consists of spindle-shaped smooth muscle cells interspersed with collagen and elastic fibers.
    Age-related change The endometrium undergoes cyclical changes during the menstrual cycle, thickening and then shedding in response to hormonal fluctuations. The myometrium remains relatively constant in thickness throughout the menstrual cycle.
    Ultrasound appearance The endometrium appears as a uniform, echogenic (bright) layer on ultrasound, with a well-defined interface between the endometrium and myometrium in normal cases. The myometrium appears as a non-uniform, hypoechogenic (darker) layer on ultrasound.
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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.