I. Gross Anatomy and Histology
After completing this section you will be able to:
- list and identify the various parts of the uterine corpus
- describe the gross anatomy and histology of the corpus
The body of the uterus is the upper, broad, piriform part of the uterus.
It is a hollow, thick-walled, muscular organ with a flat anterior surface
and a convex posterior surface. The component parts are the:
- Fundus, the dome-shaped upper part of the corpus above and between
the entrances of the fallopian tubes.
- Cornu, the region of the body on each side, where the fallopian tube
- Body, the part that lies below the entrances of the fallopian tubes.
- Isthmus, the narrow zone of constriction on the external surface
just above the cervix and serves as the junction between corpus and cervix.
It corresponds in the interior to the lower uterine segment, which
ends at the internal cervical os.
- Endometrial cavity, the lumen of the body which, in coronal section,
Question: What is the clinical importance of the lower uterine segment?
The endometrial cavity is lined by the endometrium, which is made
up of epithelium and stroma. The surface epithelium invaginates to
form numerous tubular endometrial glands, which extend down into the specialized
endometrial stroma. The endometrium consists of a thick superficial layer
made up of the outer two-thirds and called the functional layer (zona functionalis)
and a thin, deep, basal layer (zona basalis) formed by the inner one-third.
The functional layer undergoes cyclic changes in response to sex hormones
and is shed with each menstruation. The basal layer is the germinative portion
and, with e ach cycle, regenerates a new functional layer.
Underlying the endometrium is the myometrium, the thick, smooth muscle
layer of the corpus. Externally is the serosa, which is the
peritoneal covering of the uterus..
Endometrium with underlying myometrium (lower third).