Bony Pelvis (1) Flashcards
Which bones does the pelvic girdle consist of? (3)
- Sacrum
- 2 x os coxae
Each os coxae consist of
3 bones:
- Ilium
- Ischium
- Pubis
What does the sacrum consist of?
Sacrum
* 5 fused sacral vertebrae
Sacrum
What are the parts of the upside down triangle? (5)
- Base
- Apex
- Ventral surface (pelvic)
- Dorsal surface
- 2 lateral margins
What is the function of the base of the sacrum?
- Supports weight of
vertebral column
Sacrum – Base
- Superior surface:
S1
Articular process - L5
Sacrum – Base
- Anterior margin
prominent:
– sacral promontory
- Wide wing-like ____ form
Ala
Sacrum – Base
What is the pelvic brim called?
- Linea terminalis – pelvic
brim
Sacrum
- Apex : (2)
- Projects downwards
- Joined to coccyx
- Pelvic Surface
- Concave –
- Transverse ridges -
- Concave – smooth
- Transverse ridges - fusion
- Pelvic Surface
- 4 anterior sacral _______
foramina
What are the features the dorsal surface?
- Convex and roughened
What are the crests associated with the sacrum? (3)
- Median sacral crest
- Medial sacral crest
- Lateral sacral crest
Sacrum
- Median sacral crest:
- Fused spinous processes
Sacrum
- Medial sacral crest:
- Fused articular processes – Indistinct ridge
Sacrum
- Lateral sacral crest:
- Fused transverse processes
- Sacral hiatus – projection =
= sacral horns
- Posterior sacral _______
foramina
What is the shape of the lateral surface of the sacrum?
- Ear-shaped structure
- Auricular facets/ surface
Sacrum:
What joints are at the sacrum? (2)
- Sacro-iliac joints
- Behind facet – sacral
tuberosity
What is the coccyx?
3-5 rudimentary segments
Remanent of embryonic tail
What is the Os Coxa? (2)
- Large, irregular bone
- Cup-shaped hollow
- Acetabulum articulates with =
head of femur
The Os Coxa forms the ____ and _____ walls of the pelvis.
anterior
lateral
Os Coxa
- Joined anteriorly –
- Joined posteriorly –
pubic symphysis
sacro-iliac joint
- Consists of 3 parts:
- Ilium – 2/5
- Ischium – 2/5
- Pubis – 1/5
Where is the Os Coxa joined?
Joined at acetabulum
When does the Os Coxa ossify?
- Ossifies at the age of 16
Ilium:
- Superior margin:
- Upper arched margin known as iliac crest
Ilium:
- S-shaped (above): (2)
- Anterior two-thirds
- Posterior third
What are the anterior two-thirds of the margin of the ilium? (2)
- Anterior superior iliac spine (ASIS)
- Anterior inferior iliac spine (AIIS)
ASIS: inguinal ligament & _______
sartorius
Ilium:
* Posterior third of the margin:(2)
- Posterior superior iliac spine (PSIS)
- Posterior inferior iliac spine (PIIS)
Ilium
Just inferior to posterior inferior iliac spine - _____ ______ ______
greater sciatic notch
What is shared with the greater sciatic notch?
shared by ilium + ischium
Ilium:
- Gluteal surface –
lateral surface
How is the ilium divided?
- Divided into 4 areas by 3 gluteal lines
Ilium:
- Lines distinct or vague: (3)
- Posterior gluteal line
- Anterior gluteal line
- Inferior gluteal line
- Posterior gluteal line
- Small posterior area gives origin to….
the gluteus maximus
- Anterior gluteal line
- Large anterior area gives origin to…
the gluteus minimus
- Anterior gluteal line
- Between two gluteal lines -
gives origin to gluteus medius
- Inferior gluteal line
- Attachment of:
- Attachment of capsule of hip joint
Ilium
Pelvic surface - _____ surface
medial
- Pelvic surface – medial surface
- 3 areas:
- Iliac fossa
- Arcuate line
- Posterior sacropelvic surface
Ilium:
* Iliac fossa – faces the….
greater pelvis (wing/ala)
Iliac fossa:
Muscle -
- Iliacus m.
- Arcuate line
What does it separate?
- Separates iliac fossa from the lesser pelvis
- Posterior sacropelvic surface
- Smooth anterior surface =
auricular surface
What does the Posterior sacropelvic surface join?
- Joins to sacrum (sacroiliac joint)
- Posterior sacropelvic surface
- Rough posterior area =
iliac tuberosity
What shape is the Ischium?
- U-shaped
What are the features of the body of the Ischium? (3)
- Contributes 2/5 of the acetabulum anteriorly
- Ischial spine
- Lesser sciatic notch posteriorly
Ischium
* Ramus
- Contributes to:
- Contributes to formation of obturator foramen
Ischium
* Ramus
- Joins to
- Joins to inferior pubic ramus and forms one pillar of the pubic arch
Ischium
* Ramus
- Ischial tuberosity: (2)
- Where the body and ramus join
- Rough surface for muscles
