Maternal Pelvis

What are the 4 functions of the pelvis ?

• Transmits body weight to lower limbs and supports upper body

• Enables movement in an upright posture

• Protects reproductive organs, bladder, rectum

• Enables parturition

What does the pelvic girdle consist of ? (4)

• 2 innominate

• 1 sacrum

• 1 coccyx

What bones does the innominate bone consist of ? (3)

Consider what fraction makes up what in terms of 1/5 ths

• Pubis 1/5

• Ischium 2/5 from the middle of the acetabulum

• Ilium 2/5

What are the holes in the sacrum called and what goes through them holes?

4 sets of foramina

Which sacral nerves pass through

How many bones and what type is the sacrum and coccyx made up of ?

5 and 4 vertebrae bones fused together

What are ligaments

They are bands of tissues that connects bone to bone and enhanced stability. However, they do not possess the ability to stretch, but in pregnancy the hormones, allow ligaments to slightly stretch.

Name 3 ligaments

Sacrospinous - sacrum to ischial spine

Sacrotuberous - sacrum to ischial tuberosity

Sacroiliac - sacrum to iliac

Name 3 joints

Lumbosacral - Fifth lumbar vertebrae and sacrum

Symphysis Pubis - cartilaginous joint joining the anterior portion of the pubis bone

Sacrococcygeal joint - cartilaginous joint joining the sacrum and coccyx

Define pelvic brim

Pelvic brim is in the inlet to the true pelvis

Name all 8 parts of pelvic brim

1. Sacral Promontory

2. Sacral Ala (wing)

3. Sacroiliac Joint

4. Iliopectineal Line

5. Iliopectinal Eminence

6. Superior Pubic Ramus

7. Upper Inner Border of Pubic Bone

8. Upper Inner Border of Symphsis Pubis

Define Pelvic Cavity

Say three characteristics

What lies between inlet and outlet

• Wedge Shaped

• Shallow at Front

• Deep at Back

What is the anatomical outlet ?

Name the parts (4)

• Tip of the Coccyx

• Ischial Tuberosities

• Sacrotuberous ligaments

• Pubic Arch

What is the obstetrical outlet ?

Name the 4 parts

• Lower inner border of Symphysis Pubis

• Ischial Spine

• Sacrospinous Ligament

• Lower Inner Border of the Base of Sacrum

Diameters of the Pelvis

Brim Anteroposterior RL Oblique Transverse

Cavity

Outlet

11 cm 12 13cm

12 cm 12 12cm

13 cm 12 11cm

Name the first layer of the pelvic floor and the two pouches

Explain what the first layer is

Pelvic Peritoneum - Uterovesical and Rectovaginal pouch

Membrane that cover the uterus, fallopian, tubes, rectum and bladder

What is the pelvic floor (3)

Name the 7 functions of pelvic floor

The pelvic floor is made up of muscles and ligaments, which are Hammock like structure

• Aids in process of defecation and micturition

• Maintained intra-abdominal pressure when laughing, coughing and more

• Assists in the process of childbirth in rotation of presenting part

• Aids in sexual function

• Supports the pelvic organs

Name the second layer of the pelvic floor and 3 things it’s made up of

Name where this body part is found (2)

What adaptation does this layer have as extra support is needed

Endopelvic Fascia

Made up of :

• Connective tissues

• Elastic fibres

• Collagen fibres

Found between pelvic organs and sidewalls of the pelvic cavity

The fascia thickens and other ligaments are created

Name the 5 ligaments

Transverse Cervical Ligament

Broad Ligament

Round Ligament

Uterosacral Ligament

Pubcervical Ligament

Where does the transfer cervical ligament attach? (3)

What does it house (2)

Where does it originate

The ligaments arise from the walls of the cervix, and the lateral fornices of the vagina and attaches to the lateral pelvic walls

This houses uterine, arteries and veins

This originates from the inferior border of the broad ligament.

Where does the Broad ligament originate from ?

What is the broad ligament?

What is covered in the broad ligament?

The broad ligament extend from the lateral pelvic walls on both sides

The ligament is a sheet of peritoneum

The ligament folds over the internal female, genitalia, anteriorly and posteriorly

What is the function of the round ligament?

Where does the round ligament originate and attach itself?

The function is to keep the uterus in place

It originates at the uterine horns and attaches itself to the labia majora

What is the function of the pubocervical ligament?

Where does the pubocervical ligament originate and attach itself to?

Defined the feature of this ligament

The function of this ligament is to support the uterus

The ligament originates at the cervix and attaches itself to the posterior surface of the symphysis pubis.

Bilateral structure of fibrous bands

What is the function of the uterosacral ligament?

Where does the uterosacral ligament originate and attach itself to?

Define the feature of this ligament

The function is to support the uterus

The ligament originates at the walls of the cervix and attaches to the sacrum, specifically the sacroiliac joint.

This ligament is a bilateral structure of fibrous bands.

Name the levator ani muscles (3)

• Puborectalis

• Pubococcygeus

• Iliococcygeus

Where is the attachments for the puborectalis?

What is its function?

This originates from the posterior surface of the pubis and forms a U-shaped sling around the anal canal.

Its function is to maintain faecal continence. It’s create a kink in the rectum.

Where is the attachments for pubococcygeus?

Which two muscles is the pubococcygeus located between?

This muscle originates from the posterior surface of the pubis and attaches to the coccyx and anococcygeal ligament and performs most of the work.

it is located between the puborectalis and iliococcygeus.

Where does the iliococcygeus attach to?

The iliococcygeus originates from the ischial spines and in the internal obturator fascia (pelvic walls) attaches to the coccyx, perineal body, anal, coccygeal ligament.

Name, the superficial muscles of the pelvic floor (5)

• Bulbocavernosus

• Ischiocavernosus

• Transverse Perinei

• External Amal Sphincter

• Urethral Sphincter

Where does the ischiocavernosus ?

What is the function of this muscle?

Arises from the ischial tuberosities and upwards along the pubic arch. It then inserts into the corpora carvenosa of the clitoris.

The function of this method is to maintain clitoral erection

What is the transverse perineal muscle?

What is the function of this muscle?

Passes from each ischial tuberosity meeting in the centre of the perineal body

The function of this message is to provide strength and support to the perineal body

What is the function of the urethral sphincter muscle and where does it attach?

The function of this method is to control micturition, and the muscle arises from one pubic bone encircles the urethra and insert at the opposite pubic bone

Where does the bulbocavernosus muscles attach to?

What is the function of this muscle?

This muscle extends from the perineal body in circling the vagina and urethral orifice. This massage, then inserts into the dorsal root of the clitoris.

The function of this muscle is vaginal contractions, the erection of the clitoris and orgasm during sexual activity.

Describe the shape of the muscle.

Where does the external anal sphincter originate from and attach to?

What is the function of the anal sphincter? (3)

The anal sphincter is an oval shaped muscle, which encircles the anus. It is fused with the bulbocavernosus and it attaches to the anal, coccygeal ligament and the tip of the coccyx.

It is responsible for the voluntary control of faeces and helps keep the anal canal and anus closed.