Flashcards in Session 4 - The pelvis Deck (19)
What are the two main muscles of male perineum?
What does bulbospongiosus do?
Helps to expel last drops of urine and maintain erections
What does ischiocavernosus do?
Compresses veins, helping ot maintain erections
What are the three parts of the hip bone?
What is the pelvic girdle made up of?
Right and left hip bones
Where do the hip bones articulate with the sacrum?
Where do the hip bones articulate with each other?
What is a gynecoid pelvis?
o Round inlet
o Straight side walls
o Ischial spines not too prominent
o Well-rounded greater sciatic notch
o Well-curved sacrum (to fit with foetal head)
o Sub-pubic arch > 900
Give five differences between male and female pelvi
- Male thick and heavy
- Female - Thin and light
Pubic arch and subpubic angle
- Male - Narrow (80)
- Male, round
- Female, oval
- Male - large
Female - Small
Greater sciatic notch
- Male - Narrow
- Female - > 90*
What is the pelvic inlet formed by?
o Promontory and ala of the sacrum posteriorly
Superior surface of its lateral part, adjacent to the body of the sacrum
o Right and left linea terminalis anteriorly
Arcuate line on the inner surface of the ilium
Pectineal line and pubic crest
What are three measurements which must be made in a clinical assesment of the pelvic inlet?
What is the anatomic conjugate?
Measured from the sacral promontory to the superior border of the pubic symphysis
What is the obstetric conjugate?
Measured from sacral promontory to the midpoint of the pubic symphysis.
Minimum diameter of the canal, as this is where the pubic bone is the thickest
What is the diagonal conjugate?
Measured from sacral promontory to the inferior border of the pubic symphysis
What is the pelvic outlet formed by?
o Pubic arch anteriorly
o Ischial tuberosities laterally
o Inferior margin of the sacrotuberous ligament posterolaterally
o Sacrospinous ligament also present
o Tip of the coccyx posteriorly
What is the pelvic inlet made up of posteriorly?
What happens to the sacrotuberous ligament during child birth?
Progesterone works to soften the ligament to increase the size of the pelvic outlet to aid childbirth
What is the greater pelvis bounded by?
o Superior to the pelvic inlet
o Bounded by the iliac alae posterolaterally
o Bounded by the anterosuperior aspect of the S1 vertebra posteriorly
o Occupied by abdominal viscera (E.g. the ileum and sigmoid colon)