Lecture 16: Pelvic Girdle Flashcards
The pelvic girdle consists of:
The right and left hip bones and the sacrum
True or False
The Sacrum is part of the axial skeleton.
False, it is part of both the axial and appendicular skeletons.
What are the functions of the pelvic girdle?
Connect the lower limb to the axial skeleton
Transfer weight from the axial skeleton to the lower limb during standing and walking
Provide attachment site for strong muscles of the gluteal and abdominal regions
Provide support for pelvic organs
What are the hip bones formed by?
- ilium
- ischium
- pubis
When are the hip bones fully fused?
Not completely fused until after puberty
What is the acetabulum?
The socket for the head of the femur
What is the sacrum formed by?
5 fused verterbrae
What is the sacral canal a continuation of?
The vertebral canal
What does the sacral canal contain?
the cauda equina
What is the cauda equina?*
The bundle of spinal nerves that descends pas the distal end of the spinal cord
What is in the same vertical plane when in anatomical position?
the ASIS and the pubic symphysis
What is the function of the public symphysis?
It is in a position to support the weigh tof the bladder of the sacroiliac joints, so the pelvis has a tendency to rotate
What are the 2 ligaments that resist the rotation of the pelvis?
- sacrotuberous ligament
- sacrospinous ligament
Where is the sacroiliac joint?
Where the sacrum articulate with the left and right hip bones
What is the sacroiliac joint classified as?
Classified as a compound joint
- anteriorly, it is considered synovial
- posteriorly, it is less mobile and is classified as a syndesmosis
What is the publc symphysis?
The left and right public bones articulate at the pubic symphysis
What is between the 2 pubic bone and what is it reinforced by?
- the fibrocartilaginous interpubic disc is reinforced superiorly and inferiorly by public ligaments
What is the sacral plexus?
Sacral spinal nerves (S1 - S5) exit the intervertebral foramina and their anterior rami form a plexus of nerves within the psoas major muscle
What are the terminal branches of the sacral plexus?
- superior gluteal nerve
- inferior gluteal nerve
- nerve to quadratus femoris
- nerve to obturator internus
- nerve to piriformis
- sciatic nerve (common fibular + tibial)
What is the lumbosacral trunk?
Large nerve that is formed by the L4 and L5 roots
What is the large sciatic nerve?
The lumbosacral trunk (L4, L5) unites with the S1, S2, and S3 roots to form the large sciatic nerve
