Anatomy of the Pelvis Flashcards
List the functions of the bony pelvis
Support of the upper body when sitting and standing
Transferrence of weight from the vertebral column to the femurs to allow standing and walking- one column -> two columns
Attachment for muscles of locomotion and abdominal wall
Attachment for external genitalia
Protection of pelvic organs, their blood and nerve supplies, their venous and lymphatic drainage
Passage for childbirth
What does the bony pelvis consist of?
2 hip bones
Sacrum
Coccyx
What is each hip bone made up of?
Fusion between ilium, ischium, pubis
What is not part of the pelvic girdle?
Coccyx
What generally covers the iliac fossa?
The iliacus
To what do the hamstring s attach?
Ischial tuberosity
Described the pelvic inlet
- Sacral promontory- prominent
- Ilium
- Superior pubic ramus
- Pubic symphysis
Describe the pelvic outlet
- Pubic symphysis
- Ischiopubic ramus
- Ischian tuberosities
- Sacrotuberous ligaments
- Coccyx
what is commonly called the pelvic rim?
Bony edge of pelvic inlet
What is continuous with the abdominal cavity?
Pelvic cavity
What is within the pelvic cavity?
Pelvic organs and supporting tissues
What are the palpable surface landmarks?
Iliac crest
Ischial tuberosity
ASIS
PSIS
What kind of joint is the sacroiliac?
generally referred to as a synovial joint- actually the posterior part is a syndesmoses (more fibrous ligaments)
What are the key ligaments of the pelvis?
Sacrospinous ligament
Sacrotuberous ligament
What is the role of the Sacrospinous and
Sacrotuberous ligament
Ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebra column
What covers the obturator foramen?
Obturator membrane, apart from the obturator canal
What passes through the obturator canal?
Obturator nerves and vessels
Why does the pelvis tend to fracture in more than one place?
It is a ring of bones- think pretzel
What is often fatal about pelvic trauma?
Haemorrhage
What is different about the male and female pelvises?
- AP and transverse diameters of the female pelvis are larger than in the male- this is true at both the inlet and the outlet.
- The subpubic arch and angle is much bigger in the female than in the male. If you put your thumb and index out- this is a female. 1st and 2nd finger is a male.
- Pelvic cavity is more shallow in the female.
What is moulding?
Movement of one bone over another to allow the foetal head to pass through the pelvis during labour
What are the clinically important fontanelles?
Anterior and posterior
When should the anterior fontanelle close?
between 18-24 months
What is the vertex?
An area of the foetal skull outlined by the anterior and posterior fontanelles and the parietal eminences
Why is the vertex important?
allows the skull to be palpated in labour
In which way should the foetus enter the pelvic cavity?
Facing either right or left
What is the station?
The distance of the foetal head from the ischial spines. A negative number means the head is superior to the spines, a positive number means the head is inferior to the spines.
What way should the foetus pass through the pelvic cavity?
Rotate into a flexed position, chin to chest
Which way should the baby leave the pelvis cavity?
Occipitoanterior position
How should the foetal head be during delivery?
Extension
What happens once the babies head is delivered?
Rotation so that the shoulders and the rest of the baby can be delivered.
