Pelvic Anatomy Notes Flashcards
What is the adnexa?
The region including the fallopian tube and ovary.
What is the false pelvis?
The region of the pelvis located above the pelvic brim.
What are fimbriae ovarica?
The one fimbriae attached to the ovary.
What is the iliopectineal line?
An imaginary line from the superior border of the sacrum to the superior margin of the pubis symphysis that divides the true and false pelvis.
What is a ligament?
An extension of a double layer of peritoneum between visceral organs.
What is menarche?
The onset of menstrual cycles.
What is menopause?
The cessation of menses.
What is the mesovarian ligament?
The posterior portion of the peritoneum that attaches to the ovary.
What is mesosalpinx?
The upper fold of the broad ligament that drapes over the fallopian tube.
What is the perineum?
The surface region in both males and females between the pubic symphysis and the coccyx; area below the pelvic floor.
What is premenarche?
The time before the onset of menstrual cycles.
What is puberty?
The process of physical changes by which a child’s body becomes an adult body capable of reproduction.
What is the true pelvis?
The region of the pelvis found below the pelvic brim.
What is the pelvic anatomy?
The pelvis begins at the iliac crests and ends at the symphysis pubis, divided into the true and false pelvis by the iliopectineal line.
What is the true pelvis also known as?
Pelvic cavity or lesser pelvis.
What are the boundaries of the true pelvis?
Anterior boundary—symphysis pubis; posterior boundary—sacrum and coccyx; posterolateral wall—piriformis and coccygeus muscles; anterolateral wall—hip bone and obturator internus muscles; lateral boundaries—fused ilium and ischium.
What does the true pelvis contain? 4
- The female reproductive system
- Urinary bladder
- Distal ureters
- Bowel.
What is the false pelvis?
Located superior to the pelvic brim, contains loops of bowel.
What is the levator ani?
A group of muscles forming the pelvic floor that supports and positions the pelvic organs.
What is the sonographic appearance of the levator ani? 3
- Low-level
- Mildly curved linear echoes posterior to the vagina
- Hypoechoic compared with the normal uterus.
What is the iliopsoas Formed by? What kind of landmark does it serve as?
- Formed by the psoas major and iliacus muscles
- Serves as a lateral landmark of the true pelvis.
What is the sonographic appearance of the iliopsoas?
Low-level gray echoes with a distinct central hyperechoic focus.
What does the piriformis arise from? What is it a part of?
- Muscle arising from the anterior sacrum
- Part of the pelvic floor.
What is the sonographic appearance of the piriformis?
Low-level linear echoes, hypoechoic compared with the normal uterus.
What is the psoas major?
Muscle that arises from the lumbar spine and descends into the false pelvis.
What is the sonographic appearance of the psoas major? What is the shape in the transverse plane?
Low-level echogenicity, round in shape in the transverse plane.
What is the obturator internus? What does it extend through?
Muscle surrounding the obturator foramen, extending through the sciatic foramen.
What is the sonographic appearance of the obturator internus?
Low-level linear echoes abutting the lateral walls of the urinary bladder.
Are Pelvic ligaments routinely visualized? What do they appear as?
- Not routinely visualized by ultrasound
- Appear as hyperechoic, moderately thin, linear structures with intraperitoneal fluid collections.
What is the broad ligament? What does it drape over?
A wing-like double fold of peritoneum that drapes over the fallopian tubes, uterus, ovaries, and blood vessels.
What is the cardinal ligament? What does it firmly support?
Continuation of the broad ligament that extends across the pelvic floor and firmly supports the cervix.
What is the ovarian ligament?
Extends from the cornua of the uterus to the medial aspect of the ovary.
What is the round ligament?
Arises in the uterine cornua, anterior to the fallopian tubes, helping to maintain anteflexion of the uterine body.
(Connects uterus to the lower abdomen)
What is the suspensory ligament? What is it also known as?
Also known as infundibulopelvic ligament, extends from the lateral portion of the ovary to the pelvic sidewall.
What is the uterosacral ligament?
Extends from the upper cervix to the lateral margins of the sacrum, firmly supporting the cervix.
What are the arcuate vessels? What does it branch from?
Prominent vascular structures in the outer one third of the myometrium, branching from the uterine artery.
What do the radial arteries supply? (What is another name for the radial arteries?)
- Spiral arteries supply blood to the functional layer of the endometrium
- Straight arteries supply blood to the basal layer.
Where are the internal iliac arteries located? What does it supply? 2
- Posterior to the uterus and ovaries
- Supplying the bladder, uterus, vagina, and rectum.
Where do the ovarian arteries arise from?
The lateral margins of the abdominal aorta, slightly inferior to the renal arteries.
What do the uterine arteries supply? 5
- Cervix
- Vagina
- Uterus
- Ovaries
- Fallopian tubes.
What are the pelvic spaces?
Areas created by the peritoneum draping over the uterus and fallopian tubes, dividing the pelvis into anterior and posterior sections.
What is the retrouterine pouch?
The posterior cul de sac, most common site for fluid accumulation in the pelvic cavity.
What is the space of Retzius?
The retropubic space, anterior to the urinary bladder.
What is the vesicouterine pouch?
The anterior cul de sac located anterior to the uterus.
What is the vagina?
A collapsed tube consisting of an outer muscular layer and an inner mucosal layer, extending from the vulva to the cervix.
What is the sonographic appearance of the vagina?
Vaginal walls demonstrate low-level homogeneous echoes; the vaginal canal shows a central hyperechoic linear echo pattern.
What is the uterus?
A hollow, pear-shaped organ derived from the fused caudal portion of the paired, hollow müllerian ducts.
What are the tissue layers of the uterus?
Perimetrium, myometrium, and endometrium.
What is the endometrium?
Highly vascular mucous membrane lining the uterine cavity, composed of functional and basal layers.
What is the body of the uterus?
The largest portion of the uterus, located posterior to the vesicouterine pouch and anterior to the retrouterine pouch.
What is the cervix?
The proximal and inferior portion of the uterus located between the vagina and uterine isthmus.
What is the fundus of the uterus?
The dome-shaped widest, most distal and superior portion of the uterus.
What is the isthmus?
The narrow waist of the uterus located between the cervix and body of the uterus.
What is the normal sonographic appearance of the uterus?
Homogeneous mid-to-low level echogenic structure surrounding a hyperechoic endometrial cavity.
How is the length of the uterus measured?
From the fundus to the external cervical os.
What is the uterine size during premenarche?
Length: 2.0-4.0 cm, Height: 0.5-1.0 cm, Width: 1.0-2.0 cm.
What is the uterine size during menarche?
Length: 6.0-8.0 cm (nulliparous) 8.0-10.0 cm (parous); Height: 3.0-5.0 cm; Width: 3.0-5.0 cm.
What is the uterine size during postmenopause?
Length: 3.5-6.5 cm; Height: 2.0-3.0 cm; Width: 4.0-6.0 cm.
What is flexion in uterine positions?
Refers to the relationship between the body of the uterus and the internal cervical os.
What is anteflexion?
Uterine body and fundus bend significantly anterior until the fundus points inferior resting on the cervix.
What is anteversion?
Uterine body and fundus are tipped anteriorly, forming an angle ≤ 90 degrees with the vaginal canal.
What is dextroflexion?
Uterine body is displaced or flexed to the right of the cervix.
What is levoflexion?
Uterine body is displaced or flexed to the left of the cervix.
What is retroflexion?
Uterine body and fundus bend significantly posterior until the fundus is pointed inferior adjacent to the cervix.
What is retroversion?
Uterine body and fundus are tipped posterior.
What is levoflexion?
Uterine body is displaced or flexed to the left of the cervix.
Transverse imaging plane is best to evaluate whether the uterus is levoflexed.
What is dextroflexion?
Uterine body is displaced or flexed to the right of the cervix.
Transverse imaging plane is best to evaluate whether the uterus is dextroflexed.
What is retroflexion?
Uterine body and fundus bend significantly posterior until the fundus is pointed inferior adjacent to the cervix.
Transvaginal imaging is best to evaluate a retroflexed uterus.
What is retroversion?
Uterine body and fundus are tipped posteriorly, forming an angle <90 degrees with the vaginal canal.
Transvaginal imaging is best to evaluate a retroverted uterus.
What causes congenital uterine anomalies? 2
- Congenital anomalies result from improper fusion of the müllerian ducts
- Incomplete absorption of the septum between them.
What percentage of congenital uterine anomalies have coexisting renal anomalies?
20% to 30% of cases.
What is agenesis in terms of uterine anomalies?
Failure of the caudal müllerian ducts to develop, resulting in absent uterus and fallopian tubes.
Clinical findings include amenorrhea.
What is a unicornuate uterus?
A congenital anomaly where one müllerian duct develops, leading to a single uterine cavity.
Clinical findings may include hypomenorrhea and infertility.
What is a bicornuate uterus?
Partial fusion of the müllerian ducts resulting in two uteri in the superior portion of the uterus.
Clinical findings may include spontaneous abortion.
What is a septate uterus?
Complete fusion of the müllerian ducts with failure to completely reabsorb the septum, resulting in two uterine cavities and one fundus.
Most common type of müllerian duct anomaly.
What is the anatomy of the ovaries?
Paired, elliptical-shaped endocrine glands located lateral to the uterus, composed of an outer cortex and a central medulla.
What hormones do the ovaries produce?
Estrogen, secreted by the follicle, and progesterone, secreted by the corpus luteum.
What is the normal sonographic appearance of the ovary?
Ovoid low-to-medium-level echogenic structure, isoechoic to hypoechoic compared with the normal uterus.
What is the normal ovarian size at menarche?
2.5 to 5.0 cm in length, 1.5 to 3.0 cm in width, and 0.6 to 2.2 cm in height.
What is the function of the fallopian tubes?
Attract and transfer ova from the surface of the ovary to the endometrial cavity.
What are the segments of the fallopian tube?
Interstitial, isthmus, ampulla, and infundibulum.
What is the normal sonographic appearance of the fallopian tube?
Normal fallopian tube is not routinely visualized but may appear as a long echogenic tenuous structure extending laterally from the uterine wall.
What is the purpose of bladder distention in transabdominal imaging?
Displaces uterus posteriorly and bowel laterally, providing an acoustic window to visualize pelvic structures.
What are the contraindications for endovaginal imaging?
Any patient who does not or cannot willingly consent, premenarchal or virginal patients, and severe pain during examination.
What are the indications for non-gravid female pelvis ultrasound? 7
- Pelvic pain
- Pelvic or uterine mass
- Abnormal uterine bleeding
- Amenorrhagia
- Dysmenorrhea
- Bloating
- Family history of gynecological carcinoma.
What is the normal sonographic appearance of the urinary bladder?
Anechoic, fluid-filled structure located in the pelvic midline.
What is the normal postvoid residual in adult patients?
Postvoid residual normally should not exceed 20 mL.
What is the normal sonographic appearance of the bladder?
Anechoic, fluid-filled structure located in the pelvic midline.
How do ureteric orifices appear on sonography?
Ureteric orifices appear as small echogenic protuberances on the posterior aspect of the bladder.
What is the normal bladder wall thickness?
Bladder wall thickness should not exceed 5 mm.
What is a bladder diverticulum?
Bladder diverticulum is caused by bladder wall muscle weakness leading to herniation of the mucosa through the muscular wall.
What are the clinical findings of a bladder diverticulum? 4 (s/s)
- Asymptomatic
- Urinary tract infection, pelvic pain
- May be associated with bladder obstruction
- chronic inflammation.
What are the sonographic findings of a bladder diverticulum?
Anechoic pedunculation of the urinary bladder; neck of diverticulum is small and may enlarge when bladder contracts.
What are differential considerations for bladder diverticulum? 3
- Ovarian cyst
- Fluid-filled bowel
- Ascites.
What is a bladder ureterocele?
Congenital obstruction of the ureteric orifice.
What are the clinical findings of a bladder ureterocele? (S/S) 2
- Asymptomatic
- Urinary tract infection.
What are the sonographic findings of a bladder ureterocele?
Hyperechoic septation seen within the bladder at the ureteric orifice.
What are differential considerations for bladder ureterocele?
Artifact.
What is bladder calculus?
Bladder calculus is caused by urinary stasis and can migrate from the kidneys.
What are the clinical findings of bladder calculus? 4 (s/s)
- Asymptomatic
- Hematuria
- Urinary frequency
- Urgency.
What are the sonographic findings of bladder calculus?
Hyperechoic focus within the urinary bladder with posterior acoustic shadowing; mobile with patient position change.
What are differential considerations for bladder calculus? 2
- Intestinal air
- Calcified vessel.
What is cystitis?
Cystitis is an infection with female prevalence.
What are the clinical findings of cystitis? (S/S) 4
- Dysuria
- Urinary frequency
- Leukocytosis
- Hematuria.
What are the sonographic findings of cystitis?
Focal or diffuse increase in bladder wall thickness; mobile internal echoes.
What is bladder sludge?
Bladder sludge is debris in the bladder.
What are the clinical findings of bladder sludge?
Asymptomatic.
What are the sonographic findings of bladder sludge?
Homogeneous low-level echoes; mobile with patient position change.
What are differential considerations for bladder sludge? 2
- Cystitis
- Hematuria.
What are the risk factors for bladder malignancy? 6
- Elderly
- Male prevalence
- Analgesic abuse
- Tobacco use
- Excessive coffee consumption
- Recurrent UTI.
What does transitional cell carcinoma present with? (S/S) 3
Transitional cell carcinoma presents with
1. Painless hematuria
2. Frequent urination
3. Dysuria.
What are the sonographic findings of transitional cell carcinoma? 3
- Polypoid echogenic bladder mass with irregular margins
- Immobile with patient position change
- May demonstrate irregular bladder wall thickening.
What are the findings of a benign tumor in the bladder? 3
- Echogenic intraluminal mass with smooth margins
- immobile with patient position change
- internal vascular flow.
What pelvic ligament extends from the cornua of the uterus to the medial aspect of the ovary?
Round ligament.
What do prominent anechoic structures near the periphery of the uterus most likely represent?
Nabothian cysts.
