Anatomy 1 - Pelvic # and Childbirth Flashcards
What are the other names for the hip bone?
Innominate bone
Pelvic bone
What is the pelvic girdle?
Structure formed by bony pelvis (not including coccyx)
What bones make up the pelvis?
2 hip bones
Sacrum
Coccyx
What makes up the hip bone?
Ilium
Ischium
Pubis
Where do the ilium, ishium and pubis fuse?
At the acetabulum
What muscle attaches at iliac fossa?
Iliacus
What muscle attaches at gluteal fossa?
Gluteal muscles
Where does the iliac crest stretch from?
PSIS to ASIS
What structures attach at the ASIS?
Inguinal ligament
Sartorius muscles
Where does inguinal ligament span to and from?
From ASIS
To pubic tubercle
How is the location for a lumbar puncture found?
Palpate the iliac crest to find L4/L5
What is the part of the hip bone that you sit on?
Ischial tuberosity
What can cause ischial bursitis?
Sitting on hard surface for long time
What connects the ischium and pubis?
Ischiopubic ramus
Are the greater and lesser sciatic notches more or less blunted in females than males?
More blunted in females
What group of muscles attach to the ischial tuberosity?
Hamstrings
Where can the ischial spines be palpated on vaginal examination?
At 4 and 8 o’clock postions
What is the sacral promontory?
Bulge of first sacral vertebrae
What is a ramus?
A ‘branch’ of bone
What are the three joints of the pelvis?
Sacroiliac joint Hip joint (where femur attaches) Pubic symphysis
What type of joint is the hip joint?
Ball and socket synovial joint
What type of joint is the pubic symphysis?
Secondary cartilagenous
Is there much movement at the sacroiliac joint? Why/ why not?
Not much movement
Held in place by ligaments
Describe the course of the pudendal nerve
Out of pelvis via greater sciatic forament, curls around sacrospinal ligament then in via lesser sciatic foramen
What covers the obturator foramen?
Ligamentous band which is specialised part of obturator membrane
What are the ligaments of the pelvis?
Sacrospinous
Sacrotuberous
Where does sacrospinous ligament span?
Sacrum to iliac spine
Where does sacrotuberous ligament span?
Sacrum to ischial tuberosity
What is the function of the pelvic ligaments?
Ensure the inferior part of the the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebral column e.g. jumping from height/ late pregnancy
What hormones relax the pelvic joints during birth?
Relaxin
Progesterone
What causes back pain in pregnancy?
Increased tension on sacrotuberous ligament
What foraminae do the pelvic ligaments form?
Sciatic foramen
What makes up the pelvic inlet?
Sacral promontory
Ilium
Superior pubic ramus
Pubic symphysis
What makes up the pelvic outlet?
Pubic symphysis Ischiopubic ramus Ischial tuberosities Sacrotuberous ligaments Coccyx
What makes up the roof of the pelvic cavity?
Peritoneum of pelvic inlet
What makes up the floor of the pelvic cavity?
Pelvic floor i.e. levator ani
What makes up the false pelvis?
Intestines (ilius and sigmoid colon)
What makes up the true pelvis?
Pelvic organs i.e. rectum, bladder, uterus
6 functions of bony pelvis?
- Support upper body when sitting and standing
- Transfer weight from one long pole (vertebral column) to two poles (legs)
- Attachment for muscles of locomotion and abdo wall
- Attachment for external genitalia
- Protection of pelvic organs, their blood and nerve supply, venous and lymphatic drainage
- Passage for childbirth
What is the significance of the structure of the pelvic for trauma and fractures?
It is a bony ring so fractures tend to be multiple (like a polo mint) or combined with a joint dislocation
What is a straddle injury?
Fracture all 4 pubic rami
Why is trauma to bony pelvis life threatening?
Because it is highly vascular
Bony fragments can also rupture bladder
At what vertebral level does abdominal aorta become common iliac artery?
L4
At what vertebral level does common iliac become internal and excternal iliac arteries?
L5 - S1
What are the branches of the external iliac artery? (3)
Femoral artery
Inferior epigastric
Deep circumflex iliac
Branches of anterior trunk of internal iliac artery? (6)
Obturator artery Umbilical artery Uterine artery Middle rectal artery Internal pudendal artery Inferior gluteal artery
Branches of posterior trunk of internal iliac artery?
Iliolumbar artery
Lateral sacral arteries
Superior gluteal arteries
What structures does the internal iliac artery supply?
Pelvis
Gluteal muscles
What are the minor arteries of pelvis?
Gonadal arteries (testicular and ovarian)
Median sacral arteries
Superior rectal arteries
Where do gonadal arteries arise from?
Abdominal aorta
How does testicular artery reach scrotum?
Via inguinal canal therefore doesn’t enter the pelvis
What is the venous drainage of the pelvis?
Femoral vein
External iliac (joins with internal iliac)
Common iliac
IVC
Compare and contrast the female and male pelvic shape and structure
Female
Larger AP and transverse diameters at pelvic inlet and outlet
Wider pubic arch and subpubic angle
Shallower pubic angle
What are the fontenelles of foetal skull?
Anterior and posterior
What are the sutures of the foetal skull?
Coronal
Lamboid
Sagittal
What is moulding?
Movement of one bone over another during labour - only possible due to fontanelles (foetal skull is not ossified)
What foetal skull diameter is the longest?
Occipitofrontal diameter is longer than biparietal diameter
What fontanelle is the largest and when does it ossify?
Anterior fontanelle
Ossifes around 9 - 18 months
When does posterior fontanelle ossify?
3 months
What causes a depression in the fontanelles?
Dehydration of baby
What causes bulging in the fontanelles?
Elevated cranial pressure
What is meant by the station during labour?
Distance of foetal head from ischial spines?
What is meant by negative or positive station?
Negative - head above spines
Positive - head below spines
Describe ideal positioning of foetal head during labour
Transverse head at pelvic inlet
Rotate and flex as descending through pelvic cavity
Occipitoanterior and extended at pelvic outlet
Final rotation so shoulders can be delivered
