Normal Anatomy of the Female Pelvis

Vocabulary flashcards covering normal female pelvic anatomy including imaging approaches, skeletal boundaries, pelvic muscles, suspensory ligaments, pelvic organs, uterine layers, uterine positions, fallopian tube segments, and ovarian structure based on Chapter 5 lecture notes.

Transabdominal pelvic imaging

An ultrasound imaging approach that provides a global view of the true and false pelvis, utilizes lower frequency settings, and requires the patient to drink at least $32\,\text{oz}$ of fluid prior to the exam to fill the bladder.

Transvaginal pelvic imaging

Also known as endocavity or endovaginal imaging; an ultrasound approach that uses a higher frequency transducer for increased resolution and decreased depth, performed with an empty bladder.

Innominate bones

Two large bones that form the lateral and anterior walls of the pelvis, consisting of the ilium, ischium, and pubic bone.

Linea terminalis

An anatomical landmark line that divides the pelvic cavity into two regions: the greater (false) pelvis and the lesser (true) pelvis.

Greater (false) pelvis

Also known as pelvis major; the superior portion of the pelvic cavity located above the linea terminalis that supports the intestines.

Lesser (true) pelvis

Also known as pelvis minor; the inferior portion of the pelvic cavity located below the linea terminalis.

Rectus abdominis muscle

Muscle that forms most of the anterior body wall, extending vertically from the xiphoid process to the pubic symphysis.

Psoas major muscle

Muscle originating from the lower thoracic and lumbar vertebrae that courses laterally and anteriorly through the abdomen to join with the iliacus muscle.

Iliopsoas muscle

Muscle formed below the level of the iliac crest by the merging of the psoas major and iliacus muscle fibers, inserting onto the lesser trochanter of the femur.

Iliacus muscle

Muscle arising at the iliac crest that extends inferiorly until it merges with the psoas major muscle, forming part of the lateral margins of the pelvic basin.

Obturator internus muscle

A triangular sheet of muscle anchored along the brim of the true pelvis and extending along its side wall; it can easily be mistaken for ovaries on ultrasound.

Piriformis muscle

Muscle located deeply posterior in the true pelvis, originating at the sacrum and coursing laterally to the greater trochanter of the femur.

Pelvic diaphragm

A structure composed of the coccygeus muscle posteriorly and the levator ani muscle group (iliococcygeus, pubococcygeus, puborectalis) middle and anteriorly.

Cardinal ligament

Also known as the lateral cervical ligament; originates from the lateral aspect of the cervix and connects to the lateral pelvic wall (obturator internus muscle) to support the uterus and cervix.

Uterosacral ligament

Ligament extending from the posterior aspect of the uterus near the cervix to the anterior aspect of the sacrum, providing posterior support.

Round ligament

Ligament situated anterior to the broad ligaments and inferior to the fallopian tubes, attaching the uterine cornu to the anterior pelvic wall.

Ovarian ligament

Also known as the utero-ovarian ligament; connects the inferior ovary to the uterine cornu and can be used as a landmark to help locate ovaries on ultrasound.

Broad ligament

Peritoneal fold extending from the lateral aspects of the uterus to the lateral pelvic side wall; it divides the true pelvis into anterior and posterior compartments and is only visible on ultrasound when excessive free fluid (ascites) is present.

Mesovarium

The specific portion of the broad ligament that attaches the ovary to the posterior layer of the broad ligament.

Vaginal fornices

Gutters surrounding the external cervix created by the upper portion of the vagina, categorized into anterior, posterior, and two lateral fornices.

Space of Retzius

Also known as the retropubic or prevesical space; an extraperitoneal potential space located between the pubic symphysis and the urinary bladder.

Anterior Cul-De-Sac

Also known as the vesicouterine space; the potential space located between the anterior wall of the uterus and the urinary bladder.

Posterior Cul-De-Sac

Also known as the rectouterine space or pouch of Douglas; the potential space located between the posterior wall of the uterus and the rectum, representing the most common site for peritoneal fluid collection.

Isthmus

The segment of the uterus that marks the transition from the corpus (body) to the cervix; it is the most flexible portion of the uterus and grows at the most rapid rate during pregnancy.

Internal os

The internal opening leading from the cervix into the uterine cavity.

External os

The external opening leading from the cervix into the vaginal canal.

Perimetrium

The serous outermost tissue layer of the uterus that is not visible on ultrasound.

Myometrium

The middle muscular layer of the uterus, which appears sonographically as relatively homogeneous.

Endometrium

The inner mucous membrane of the uterus, composed of a superficial functional layer that sloughs off during menstruation and a deeper permanent basal layer.

Anteflexion

Anatomical uterine variant position defined as the forward bending of the uterine fundus toward the abdominal wall.

Anteversion

The usual uterine position defined as the tipping of the entire uterus toward the anterior abdominal wall when the bladder is empty.

Retroflexion

Anatomical uterine variant position defined as the backward bending of the uterine fundus toward the rectum.

Retroversion

Anatomical uterine variant position defined as the tipping of the entire uterus backward toward the sacrum.

Interstitial portion

Also known as intramural; the segment of the fallopian tube located within the uterine wall or cornu, containing the narrowest lumen ($1\,\text{mm}$).

Ampulla

The longest and widest ($6\,\text{mm}$ lumen) portion of the fallopian tube that curves around the ovary and serves as the normal site of fertilization.

Infundibulum

The trumpet-shaped distal end of the fallopian tube featuring finger-like projections called fimbriae, which direct the released ovum into the tube following ovulation.

Ovarian cortex

The outer tissue layer of the ovary containing developing follicles, encased by a dense connective tissue layer called the tunica albuginea.

Ovarian medulla

The central tissue layer of the ovary consisting of connective tissue, blood vessels, nerves, and lymphatic vessels.

Ovarian volume formula

The mathematical formula used to calculate ovarian volume in $\text{cm}^3$: $\text{Length} \times \text{Width} \times \text{Height} / 2$.