Located at the base of the broad ligament Continuous with the connective tissue of the parametrium Attached to the pelvic diaphragm through continuity with the superficial superior fascia of the levator ani

Pelvis Anatomy Flashcards by Sally Steinbach

Name the 4 pelvic types according to Caldwell-Moloy (just name them)

Gynecoid
Anthropoid
Android
Platypelloid

How well did you know this?

Not at all

Perfectly

Describe the gynecoid pelvis according to Caldwell-Moloy and its clinical significance

Classic female shape (bowel shape)
Most favorable for vaginal birth because nice wide opening at inlet that continues to outlet

How well did you know this?

Not at all

Perfectly

Describe the anthropoid pelvis according to Caldwell-Moloy and its clinical significance

Exaggerated oval shape of inlet (wide ‘U’-shaped pubic arch)
Largest diameter is AP
Associated with delivery in OP position (more room in back of pelvis)
Also more favorable for vaginal birth
Associated with people of African decent

How well did you know this?

Not at all

Perfectly

Describe the android pelvis according to Caldwell-Moloy and its clinical significance

Classic male shape
Heart shaped at inlet (‘V’-shaped symphysis pubis), flat sacrum that does not jut out
Theoretically associated with CPD because ischial spines are closer together and pointing inwards. Ischial tuberosities (outlet) also closer together
Hard to get 2 fingers into arch of pubic symphysis

How well did you know this?

Not at all

Perfectly

Describe the platypelloid pelvis according to Caldwell-Moloy and its clinical significance

Very narrow pelvis with sacrum close to symphysis
Theoretically associated with transverse arrest
Associated with people of Island decent?

How well did you know this?

Not at all

Perfectly

What are the 4 main planes of the pelvis?

Pelvic Inlet
- Upper posterior part of the symphysis, ridge of iliac bones, and sacral promentory
- Measured by diagonal conjugate
Midpelvis
- Lower border of symphysis to midportion (junction of S4-S5) of sacrum. Interspinous diameter is narrowest point (plane of least dimensions).
- Ischial spines are limiting factor → where most babies get stuck if they are prominent.
- Ischial spines are continuous with ligaments.
Pelvic outlet
- Two dimensions/triangle. Inferior aspect of symphysis to ischial spines forms one triangle. Ischial tuberosities to sacrococcygeal joint forms the other.
Plane of greatest dimensions [IGNORE]

How well did you know this?

Not at all

Perfectly

Major Blood vessels of pelvis

Aorta bifurcates → right and left common iliac artery → bifucates into internal and external iliac arteries (right and left) at L5-S1.
Internal iliac arteries is major artery of pelvis. At the greater sciatic foramen it branches into anterior trunk (Vaginal, Uterine, Internal Pudendal, Middle Rectal, Inferior Gluteal, Obturator, Umbilical and Inferior Vesical arteries) and posterior trunk (Iliolumbar, Lateral Sacral and Superior Gluteal arteries)
Veins correspond as do many nerves

How well did you know this?

Not at all

Perfectly

Major Lymphatics of the Pelvis

How well did you know this?

Not at all

Perfectly

Levator ani muscles

Levator ani - major supporting structure for the pelvic viscera
3-part muscle mass:
- Iliococcygeus - broadest and most posterior portion. Extends more laterally from the fascia of obturator internus muscle to the tailbone
- Pubococcygeus - pubic bone (lateral of the origin of the puborectalis muscle) to the tendinous center of the perineum, anococcygeal body and tailbone
- Puborectalis - Lateral from the symphysis on both sides and encircles the rectum (anorectal junction). Partially interwoven with the external anal sphincter
Innervation of the levator ani is through the third and fourth sacral nerves

How well did you know this?

Not at all

Perfectly

Cardinal ligaments

Located at the base of the broad ligament
Continuous with the connective tissue of the parametrium
Attached to the pelvic diaphragm through continuity with the superficial superior fascia of the levator ani

How well did you know this?

Not at all

Perfectly

Nerves

Afferent (sensory) pain fibers for the uterus, tubes, and ovary enter the cord at T10, T11, and T12
- Spinal or epidural anesthesia must extend to these levels.
  - Efferent (motor) fibers to the uterus enter above these levels and thus do not interfere with contraction
Afferent innervation of the vagina and external genitalia enter at S2, S3, and S4

How well did you know this?

Not at all

Perfectly

Piriformis muscle

Posterior hip muscle
Origin: pelvic surface of sacrum
Insertion: Greater trochanter
Innervation: Sacral plexus (L5 -S1)
Functions: stabilizes pelvis (with other posterior hio muscles) and hip joint. Externally rotates and aducts: thigh

How well did you know this?

Not at all

Perfectly

Bulbocavernosus (aka bulbospongiosus) muscle

Superficial muscle of the perineum
Divided into halves that extend from just behind the clitoris to the central tendon of the perineum and serves to constrict the vagina
One of the muscles that contracts during kegel
Innervated by pudendal nerve

How well did you know this?

Not at all

Perfectly

Ischiocavernosus muscle

Connects ischium to pubic symphysis
Contracts during orgasm and kegels? (per wikipedia)
Innervated by pudendal nerve

How well did you know this?

Not at all

Perfectly

Superficial and deep transverse perineal muscles

Both innervated by pudendal nerve

How well did you know this?

Not at all

Perfectly

Central tendinous point of the perineum

(perineal body)

Study These Flashcards

Ill-defined, fibromuscular mass is located in the middle of the interischial line, between the two triangles of the perineum.
Many muscles attach at the perineal body.
- Posterior with the external anal sphincter and anterior with bulbospongiosus and the deep and superficial transverse perinei.
Extends superiorly into the rectovaginal septum of the pelvis.

Obturator internus muscle

Study These Flashcards

Originates from obturator membrane (covers the foramen created by the ischium)
Inserts: trochanter and trochanteric fossa
Function: externally rotates thigh
Innervation: sacral plexus

External and internal anal sphincter (contains muscle)

Study These Flashcards

External: made of 3 muscles
- Subcutaneous
- Superficial
- Deep
- Arise from coccyx and converge into central tendon
- Voluntary control
Internal:
- Muscular ring
- Involuntary control

Urethra (contains muscle)

Study These Flashcards

Urethral muscle is a continuation of the bladder
External urethral sphincter (only urinary sphincter?) under voluntary control
Innervated by pudendal nerve

Describe the function and location of pelvic fascia

Study These Flashcards

Sacrotuberous and Sacrospinous Ligaments

Study These Flashcards

Connect the sacrum and

Sacrotuberous - ischial tuberosities
Sacrospinous - ischial spines

Broad, Round, Ovarian, and Suspensatory ligaments

Study These Flashcards

Peritoneal Ligaments

(Uterosacral, Cardinal, Pubocervical)

Study These Flashcards

Cardinal ligament
- Located at the base of the broad ligament
- Continuous with the connective tissue of the parametrium
- Attached to the pelvic diaphragm through continuity with the superficial superior fascia of the levator ani
Pubocervical - connects cervix to pubic symphysis (not pictured)

Prenatal physiotherapy is preventative for:

Study These Flashcards

low back pain/pelvic girdle/pelvic pains
Weight gain
Incontinence

PT can also effectively treat all of the above + leg edema

Identify the significant pelvic diameters and the range of their measurements, how they are obtained, their significance and variations according to pelvic type: ## Footnote **Diagonal conjugate**

* Measured clinically * AP diameter of the pelvic inlet - sacral promontory to the inferior (lower) margin of the symphysis pubis * Normal ≥ 11.5cm * Fetus may not engage if too narrow * Platypelloid pelvis * Android pelvis

Identify the significant pelvic diameters and the range of their measurements, how they are obtained, their significance and variations according to pelvic type: ## Footnote **Obstetric conjugate**

* Measures pelvic inlet * Middle of the sacral promontory to the middle of the posterior symphysis pubis. * Normal ≥ 10 cm * Cannot measure clinically, only estimate from diagnonal conjugate * Obstetrical conjugate = Diagonal conjugate - 1.5cm

Identify the significant pelvic diameters and the range of their measurements, how they are obtained, their significance and variations according to pelvic type: ## Footnote **Transverse diameter of the inlet**

* Distance between iliopectineal lines. * Normal = ~13.5 cm * May be shorter in an anthropoid pelvis, and wider in a platypelloid pelvis

Identify the significant pelvic diameters and the range of their measurements, how they are obtained, their significance and variations according to pelvic type: ## Footnote **Interspinous diameter**

* Distance between the ischial spines. * Normally approximately 10 cm. * Smallest diameter of the pelvis that the fetal presenting part must accommodate during labor and birth

* Middle of the inferior margin of the symphysis pubis through the middle of the transverse diameter and to the sacrum (where S4 and S5 meet) * Normally ≥ 11.5 cm or more. * Should have an angular shape. * Anthropoid pelvis - “hollow” sacrum → persistent OP positioning (more room for the back of the head)

Extends from the middle of the inferior margin of the symphysis pubis to the sacrococcygeal joint. Normally ≥ 11.5 cm or more. Note that if the coccyx is “j-shaped,” there is a chance of its breaking in labor

* Transverse diameter of the outlet * Distance between the inner aspect of the lowermost part of ischial tuberosities. * Measured by placing the fist at the perineum in pelvimetry * Normally ~ 10 cm * Platypelloid pelvis - wider * Android pelvis - more narrow → significant molding

Discuss maternal positioning and its affect on fetal position \*Thank you Rebecca for this card\*

* Standing, kneeling, sitting, squatting; movement during labor: * Widens pelvic dimensions - positions the pelvis in a perpendicular relationship to the maternal spine and “vertical plane of the uterus” * Patient on knees or standing while leaning forward on a birthing ball: “align the long axis of the uterus and fetus with the mother’s pelvis and facilitate occiput anterior positions” * Lithotomy, lateral, supine, semi-recumbent - place pressure on the maternal back and sacrum, which can be detrimental to an optimally open pelvis. * Peanut ball between the legs while lying in bed: pelvic outlet becomes wider

Pelvis Anatomy Flashcards

(32 cards)