SONO 202 OB/GYN SONO 202 OB/GYN ONLINE REVIEWONLINE REVIEW

Normal Anatomy and Physiology of the Normal Anatomy and Physiology of the Female PelvisFemale Pelvis

The bones of the pelvis:The bones of the pelvis:

1. 2 innominate1. 2 innominate 2. sacrum2. sacrum 3. coccyx3. coccyx

*Iliopectineal line(linea terminalis) *Iliopectineal line(linea terminalis) separates the true and false pelvis. separates the true and false pelvis. Extends from the sacral prominence to the Extends from the sacral prominence to the pubic symphysis.pubic symphysis.

The muscles of the false pelvis.The muscles of the false pelvis.

1. psoas major1. psoas major 2. iliopsoas/iliacus2. iliopsoas/iliacus

The muscles of the true pelvis.The muscles of the true pelvis.

1. levator ani and coccygeus1. levator ani and coccygeus 2. Obturator internus2. Obturator internus 3. piriformis3. piriformis

Bladder/UretersBladder/Ureters

Bladder is located posterior to the Bladder is located posterior to the symphysis pubis and anterior to vagina.symphysis pubis and anterior to vagina.

Ureters are not normally seen Ureters are not normally seen sonographically. May see urine “jets”.sonographically. May see urine “jets”.

VaginaVagina

The vagina is located posterior to bladder, The vagina is located posterior to bladder, anterior to rectumanterior to rectum

Length- 9 cmLength- 9 cm The fornices are potential spaces. The fornices are potential spaces.

Posterior fornix surrounds the posterior Posterior fornix surrounds the posterior aspect of the external cervix. Lateral fornix aspect of the external cervix. Lateral fornix surround lateral aspect of cervix and surround lateral aspect of cervix and anterior fornix surrounds anterior aspect.anterior fornix surrounds anterior aspect.

UterusUterus

The uterus is composed of: fundus, body The uterus is composed of: fundus, body (corpus), cervix (isthmus)(corpus), cervix (isthmus)

Cervix is composed of:Cervix is composed of:

endocervix, exocervixendocervix, exocervix The 3 layers of the uterus:The 3 layers of the uterus: 1. perimetrium1. perimetrium 2. myometrium2. myometrium 3. endometrium3. endometrium

Uterine SizeUterine Size

Nulliparous (non pregnant)- Length- 6-8 cm, Nulliparous (non pregnant)- Length- 6-8 cm, AP- 3-5 cmAP- 3-5 cm

Parous (past pregnancies) - Length- 8-10 Parous (past pregnancies) - Length- 8-10 cm, AP- 5-6 cm (fundus to cervix ratio 2:1)cm, AP- 5-6 cm (fundus to cervix ratio 2:1)

Postmenopausal (after menopause)- Postmenopausal (after menopause)- Length- 3-5 cm, AP- 2-3 cm. (fundus to Length- 3-5 cm, AP- 2-3 cm. (fundus to cervix ratio 1:1)cervix ratio 1:1)

* Size of the uterus depends on age and * Size of the uterus depends on age and number of pregnancies!number of pregnancies!

Pediatric Uterus/CervixPediatric Uterus/Cervix

Newborn uterus may be enlarged due to Newborn uterus may be enlarged due to maternal hormones in fetal circulation. maternal hormones in fetal circulation. Cervix may be larger than the body of the Cervix may be larger than the body of the uterus.uterus.

EndometriumEndometrium

The 2 layers:The 2 layers: 1. superficial functional (zona functionalis)1. superficial functional (zona functionalis)

2. basal layer- regenerates new 2. basal layer- regenerates new endometriumendometrium

Endometrial measurement is typically done Endometrial measurement is typically done in the in the APAP dimension, long orientation. dimension, long orientation.

Uterine LigamentsUterine Ligaments

1. Broad Ligament- extend from lateral 1. Broad Ligament- extend from lateral aspects of the uterus, attaches to side wallaspects of the uterus, attaches to side wall

mesosalpinx, mesovarium, mesometriummesosalpinx, mesovarium, mesometrium 2. Round ligament-anterior and inferior to 2. Round ligament-anterior and inferior to

broad ligaments, attach cornua to anterior broad ligaments, attach cornua to anterior wall, keep uterus tilted forward.wall, keep uterus tilted forward.

Cardinal and Uterosacral-provides primary Cardinal and Uterosacral-provides primary support to uterussupport to uterus

Uterine PositionsUterine Positions

The following slides demonstrate the The following slides demonstrate the different uterine positions. different uterine positions.

Version relates to the relationship of the Version relates to the relationship of the cervix to vagina.cervix to vagina.

Flexion relates to the relationship of the Flexion relates to the relationship of the fundus to the cervix.fundus to the cervix.

Most typical position seen.Most typical position seen.

Fallopian TubeFallopian Tube

Length- 7-12 cm Length- 7-12 cm 4 segments of the tube:4 segments of the tube: 1. intramural (interstitial)- narrowest 1. intramural (interstitial)- narrowest

segmentsegment 2. isthmus- narrow segment2. isthmus- narrow segment 3. ampulla – longest portion3. ampulla – longest portion 4. infundibulum- trumpet shaped4. infundibulum- trumpet shaped

OvariesOvaries Ovaries are located anterior to internal Ovaries are located anterior to internal

iliac artery/vein, iliac artery/vein, medial to external iliac medial to external iliac artery and veinartery and vein

2 different layers:2 different layers:

1. cortex- outer layer- source of 1. cortex- outer layer- source of eggs/ovulationeggs/ovulation

2. medulla- center, vessels and connective 2. medulla- center, vessels and connective tissuetissue

*Ovaries produce 2 hormones: estrogen, *Ovaries produce 2 hormones: estrogen, progesteroneprogesterone

Ovarian SizeOvarian Size

Ovarian volume- length x width x AP x Ovarian volume- length x width x AP x 0.5230.523

Varies from book to book and with age!Varies from book to book and with age!

TATA

TVTV

2 ovarian ligaments:2 ovarian ligaments: 1. ovarian- posterior to fallopian tubes1. ovarian- posterior to fallopian tubes 2. suspensory (infundibulopelvic)- superior 2. suspensory (infundibulopelvic)- superior

to broad ligament, lateral to fimbriato broad ligament, lateral to fimbria

Pelvic VasculaturePelvic Vasculature

Vessels of the pelvis include:Vessels of the pelvis include: 1. CIA- off of aorta1. CIA- off of aorta 2. EIA- off of CIA2. EIA- off of CIA 3. IIA- off of EIA3. IIA- off of EIA 4. *Ovarian vein- left into LRV, right into IVC4. *Ovarian vein- left into LRV, right into IVC 5. *uterine artery- off of IIA, supplies most of 5. *uterine artery- off of IIA, supplies most of

bloodblood 6. Ovarian artery- joins with uterine artery6. Ovarian artery- joins with uterine artery 7. Arcuate arteries- in myometrium7. Arcuate arteries- in myometrium 8. Radial arteries- feed endometrium8. Radial arteries- feed endometrium

PhysiologyPhysiology

Period begins- around 11-13 years Period begins- around 11-13 years (menarche)(menarche)

Ends- 45-55 years (menopause)Ends- 45-55 years (menopause) Average cycle- 28 daysAverage cycle- 28 days Regulated by the hypothalamus.Regulated by the hypothalamus.

Menstrual CycleMenstrual Cycle

Ovarian CycleOvarian Cycle

Follicular (Days 1-14)- dominant follicle Follicular (Days 1-14)- dominant follicle reaches size of 2-2.5 cm (graafian follicle)reaches size of 2-2.5 cm (graafian follicle)

Presence of the cumulus oophorus (nodule Presence of the cumulus oophorus (nodule within follicle) usually results in ovulation within follicle) usually results in ovulation within 36 hours.within 36 hours.

Ovulatory (Day 14)- surge of LH causes Ovulatory (Day 14)- surge of LH causes ovulationovulation

Luteal (Days 15-28)- formation of corpus Luteal (Days 15-28)- formation of corpus luteum (hypervascular)luteum (hypervascular)

Follicular DevelopmentFollicular Development

Endometrial ChangesEndometrial Changes

The menstrual phases :The menstrual phases : 1. Menstrual phase- 1-5 days, 2 mm thick1. Menstrual phase- 1-5 days, 2 mm thick 2. Proliferative- 6-14 days, estrogen rises 2. Proliferative- 6-14 days, estrogen rises

and causes endometrium to thicken, 6-8 and causes endometrium to thicken, 6-8 mm mm

3. Secretory- 15-28 days, corpus luteum 3. Secretory- 15-28 days, corpus luteum secretes progesterone which causes secretes progesterone which causes further thickening, up to 18 mm thickfurther thickening, up to 18 mm thick

KNOW THIS!KNOW THIS!

*Proliferative (3 line sign)*Proliferative (3 line sign) Secretory (luteal)Secretory (luteal)

Postmenopausal EndometriumPostmenopausal Endometrium

< 5-8 mm in asymptomatic patient < 5-8 mm in asymptomatic patient 4-5 mm is borderline thick if pt. is bleeding 4-5 mm is borderline thick if pt. is bleeding

and postmenopausal.and postmenopausal. Hormone Replacement Therapy (HRT)- Hormone Replacement Therapy (HRT)-

> 8 mm is considered thick for unopposed > 8 mm is considered thick for unopposed therapy.therapy.

10-12 mm is considered thick for estrogen 10-12 mm is considered thick for estrogen phase.phase.

Pelvic RecessesPelvic Recesses

The pelvic recesses and locations.The pelvic recesses and locations. 1. vesicouterine recess (pouch) (anterior 1. vesicouterine recess (pouch) (anterior

cul-de-sac, anterior to uterus, posterior to cul-de-sac, anterior to uterus, posterior to bladder.bladder.

2. rectouterine recess (pouch) (posterior 2. rectouterine recess (pouch) (posterior cul-de-sac) (pouch of Douglas)-posterior to cul-de-sac) (pouch of Douglas)-posterior to uterus, anterior to rectum.uterus, anterior to rectum.

3. Space of Retzius- between pubic 3. Space of Retzius- between pubic symphysis and bladder.symphysis and bladder.