Uterus

How many layers of muscle are there in the myometrium?

3 layers of different muscle fibers

Normal post puberty measurements of the uterus

7.5-8cm long, 4-5cm width, 1.75-2cm in the anterior posterior dimension

What is a congenital uterine malformation

A deviation in the shape or structure of a woman's uterus that occurred during prenatal development

Describe uterus subseptus or septated

A mild anomaly marked by a midline myometrium septum between the endometrial canal. The two Müllerian ducts have fused but the partition between them is present

Describe the innermost layer of the uterus

A mucous membrane closely adherent to the myometrium. This layer is influenced by hormones and a woman's monthly cycle. It is continuous through the fimbriated extremity of the uterine tubes and with the lining of the vagina

Describe the isthmus of the uterus

A narrower area in the inferior portion of the uterus

Describe the outermost layer of the uterus

A thin layer of serous peritoneum that covers the fungus and the entire posterior and anterior uterus up to the isthmus

Describe the broad ligament

Anterior and posterior peritoneal reflections covering the uterus that extends anteriorly and laterally to the walls of the true pelvis draping over smaller structures. These double folds of parietal peritoneum extend from the uterine cornua to the lateral walls to form the broad ligaments

How is the endometrial cavity best visualized?

Anterior to posterior in the sagittal plane and the measurement of the endometrial thickness is more accurate in this plane

Name 4 variations of the uterus

Anteverted, anteflexed, retroverted, retroflexed

Where in the uterus is the site of implantation and growth of the fetus

Body of corpus of the uterus

describe anteverted uterus

Cervix and vagina form a 90 degree angle, with the body and the fundus resting on the empty bladder

Describe uterus didelphys:

Complete duplication of the uterus, cervix, and vagina. Is the result of failure of lateral fushion of the vagina and cervix

Describe retroflexed uterus

Corpus and fundus are bent at a greater posterior angle until the fundus is pointing inferiorly

Describe retroverted uterus

Corpus and fundus are tipped posteriorly and the angle of the cervix and vagina increase making them more lineally oriented

Path of the uterine artery

Courses along the lateral aspect of the uterus towards the fundus

Describe the blood supply chain to supply blood to the reproductive organs

Descending abdominal aorta bifurcates into the Lt and Rt common iliac arteries. Common iliac arteries branch into external and internal iliac arteries. Each internal iliac artery will have a parietal and visceral branch. These supply the blood to the reproductive organs

What is the narrow lumen within the cervix called

Endocervical or cervical canal

What layer is the innermost layer of the uterus?

Endometrium

Describe the location of the cardinal (lateral) cervical ligaments

Extend from lateral walls of the cervix and vagina to the obturator fascia at the lateral walls of the true pelvis

Describe the location of the uterosacral ligaments

Extend from the posterior and lateral aspect of the cervix around the lateral walls of the "" to the sacrum

Describe the location of the round ligaments

Extend laterally from the uterine Cornu to the anterior pelvic wall through the inguinal canal and anchor to the labia majora

Describe Unicornuate Uterus

Failure of one of the Müllerian ducts to form. Only one Müllerian duct forms given origin to the formation of half a uterus with only one uterine tube attachment

What is the myometrium responsible for?

For the dramatic enlarging during pregnancy and the contractions during childbirth

The part of the cervix that extends into the vagina is surrounded by what

Fornices

How does the uterus receive blood

From uterine artery which branches from the internal iliac artery

Name the 4 parts of the uterus

Fundus, body or corpus, isthmus and cervix

Describe bircornuate uterus

Have two uterine horns that are fused at one cervix. Both uteri have a uterine tune , endometrium and myometrial structures. The uterus is heart shaped. Most common of uterine malformations

What do the cardinal cervical ligaments do

Help suspend the uterus above the bladder and help to prevent downward displacement of the uterus

Briefly describe the uterus

Hollow muscular organ. Pear shaped

Flow in the spiral arteries is responsive to what

Hormonal changes of the menstrual cycle

Sonographic appearance of myometrium

Hypoechoic compared to the endometrium. Isoechoic to and continuous with the muscular walls of the vagina

What layer of the uterus is most muscular?

Myometrium is most muscular and middle layer

Are the broad ligaments true ligaments?

No

Uterus location

Normally lies at midline in the true pelvis. It tilts forward resting on the bladder

What is the most outer layer of the uterus?

Perimetrium or serosa

The perimetrium is reflected posteriorly onto the rectum to form a shallow pouch called what?

Pouch of Douglas, recto-uterine pouch OR posterior cul de sac

Describe the Arcuate Uterus

Presents a mild indentation at the level of the fundus

What do the broad ligaments do for the uterus

Provide minimal support for the uterus and prevent side to side movement of the uterus

The uterus is stabilized by what?

Several pairs of Suspensory ligaments formed by the peritoneum

Sonographic appearance of the cervix

Similar to the rest of the uterus. The endocervical canal is a continuation of the endometrial canal and appears as a fairly thin, bright echogenic strip

Sonographic appearance of perimetrium

Smooth contour and otherwise we cannot see it

Describe the walls of the cervix

Smooth muscle fibers, interlaced with collagen fibers, creating a more rigid framework

The straight arteries supply the first layer of the endometrium with smaller branches called?

Spiral arteries

The radial arteries give rise to what

Straight arteries

Name the layers of the endometrium

Superficial or functional and deep or basil

How do the uterosacral ligaments support the uterus

Supports the uterus to hold it in place preventing forward movements

What are the spaces located within the peritoneal cavity located posterior to the broad ligaments called?

The adnexa

Each uterine artery branch gives origin to what? What do they branch into?

The arcuate arteries. They loop around the uterus and branch into radial arteries

Sonographic appearance of the endometrium

The basil or deep layer appears highly echogenic and the superficial layer generally appears hypoechoic in comparison with the basil layer

What are the layers borders of the fundus of the uterus?

The cornua, this is where the uterine tubes attach and come into the uterus

The cervical canal is continuous with what

The endometrial canal superiorly and the vagina inferiorly

The spiral arteries perfuse or feed what?

The functional layer of the endometrium

What layer of the endometrium increases in size during the menstrual cycle? Explain

The functional layer. It increases in size and partially sloughs off at the time of menses

Describe anteflexed uterus

The fundus and the body are bent at a greater anterior angle until the fundus is pointing inferiorly and resting on the cervix

What do the radial arteries feed?

The myometrium

What is anteriorly reflected over the urinary bladder to form a shallow pouch and what is that pouch called?

The perimetrium. Pouch is called the Vesico-uterine pouch OR anterior cul de sac

Describe the fundus of the uterus

The top of the uterus below the pelvic brim and arching above the entry of the uterine tubes

Describe the body/corpus of the uterus

The upper two thirds portion narrowing from the fundus to the cervix. The thickest portion

What is located between the two layers of each broad ligament?

The uterine tube, round ligament, ovarian ligament and vascular structures of the uterus and ovaries

Name the 4 fornices

Two lateral fornices, one anterior fornix and one posterior fornix (deepest)

Name the congenital uterine anomalies

Uterus didelphys, bircornuate uterus, uterus sebseptus or septated, unicornuate uterus, arcuate uterus and uterine aplasia

Name the female reproductive organs that are in the pelvic cavity

Uterus, ovaries, uterine tubes and portion of the vagina

How does the size and shape of the uterus vary?

Varies greatly by age and prior pregnancies

Describe uterine aplasia

When the uterine tubes come to a blind end and only a small ribbon of fibromuscular tissue is present but no uterine body exists

Where are the arterial and venous uterine branches located

Within the peritoneal folds of the broad ligaments

Can you sustain a pregnancy with didelphys?

Yes, you can sustain a normal pregnancy in either uterus

What are the three layers of the uterus?

perimetrium, myometrium, endometrium

What allows the uterus considerable mobility

Ligaments

Describe the cervix

Lower one third cylinder segment that extends downward into the upper portion of the vagina

Where is the uterus located?

In the true pelvis between the bladder and the rectum and superior to the vagina

Describe each opening of the cervix

Internal os is the junction of the cervical canal with the endometrium canal External os is the junction of the cervical canal and the vagina

Name the openings to the cervix and what they are closest to

Internal os which is located closest to the internal uterus. External os which is located closest to the vagina

What do the round ligaments help do?

Keep the body flexed anteriorly (anteversion) and help prevent posterior movement of the uterus