Week 1 Flashcards
Bones that make up the hemi-pelvis
pubis, ilium & ischium
Divisions of the pelvis
- greater and lesser pelvis
What structure divides the pelvis
pelvic inlet
difference between child and adult pelvis
- cartilage in child pelvis
- after puberty the bones fuse
- triradiate cartilage
anatomical orientation of the human pelvis
- ant
- median
- ASIS and anterior pubic symphysis lie in same vertical plane
- coccyx appears close to the center of the pelvic inlet
- sacral promontory is located directly superior to the center of the pelvic outlet
What is the greater pelvis
- bounded by
- what lies within
- other name
- superior to pelvic inlet, bounded by iliac alae posterolaterally & anterosuperior S1 vertebra posteriorly
- abdominal viscera
- false
What is the lesser pelvis
- bounded by
- what lies within
- other name
- between pelvic inlet & outlet, bounded by pelvic surfaces of hip bones, sacrum & coccyx
- reproductive organs, bladder
- true pelvic cavity
boundaries of pelvic inlet
- Posterior
- Lateral
- Anterior
- Posterior: promontory & ala of sacrum;
- Lateral: R & L linea terminalis (arcuate line, pecten pubis & pubic crest);
- Anterior: pubic symphysis
boundaries of pelvic outlet
- Anterior
- Lateral
- Posterior
- Posterolateral
- Anterior: pubic arch;
- Lateral: ischial tuberosities;
- Posterior: tip of coccyx;
- Posterolateral: inferior margin of sacrotuberous ligament (runs between coccyx & ischial tuberosity)
3 functional roles of pelvis
Bear/transfer weight, provide attachment for mm. & reproduction
Sex differences in the Pelvis
- general structure
- greater pelvis
- lesser pelvis
- pelvic inlet
- pelvic outlet
- pubic arch and suprapubic angle
- obturator foramen
- acetabulum
- greater sciatic notch
- suprapubic angle
- M: thick and heavy, W: thin and light
- M: deep, W: shallow
- M: narrow and deep, W: wide and shallow
- M: heart shaped, narrow, W: oval and rounded, wide
- M: small, W: large
- M: narrow, W: wide
- M: <70 degrees, W: >80 degrees
- M: round, W: oval
- M:~70 degrees, W: 90 degrees
- M: narrow, W: wide
Obstetric conjugate
- what does it measure
- why is it important
- can it be truly measured?
○ minimum AP diameter of lesser/true pelvis; goes from middle of sacral promontory to posterosuperior margin of pubic symphysis
○ narrowest fixed distance through which baby’s head must pass in vaginal delivery
- cannot be measured directly d/t bladder
Diagonal conjugate
- how is it measured
○ measured by palpating sacral promontory with tip of middle finger
○ use other hand to mark level of inferior margin of pubic symphysis of examining hand
Importance of conjugates in partuition
○ if ischial tuberosities are far enough apart to permit 3 fingers to enter vagina side by side, subpubic angle considered sufficiently wide to permit passage of average fetal head at full term
What is narrowest mediolateral diameter in pelvic outlet
○ Interspinous distance (between ischial tuberosities)
If ischial tuberosities allow for 3 fingers to enter vagina side by side, subpubic angle is sufficiently wide to permit passage of an average fetal head at full term
How would you measure pelvic outlet during PE to ensure it is large enough for baby’s head to pass
○ Diagonal conjugate: palpate the sacral promontory with the tip of the middle finger, using the other hand to mark the level of the inferior margin of the pubic symphysis on the examining hand. After the hand is withdrawn, the distance between the tip of the index finger & the marked level of the pubic symphysis is measured to estimate the true conjugate (should be > 11cm)
Components of the diencephalon
Epithalamus, thalamus, hypothalamus, & subthalamus
what structure lies between the halves of the diencephalon
Third ventricle
structure that separate the thalamus dorsally and the hypothalamus and subthalamus inferiorly
Hypothalamic sulcus: small groove on lateral wall of 3rd ventricle
major lobes of the pit gland
Anterior & posterior