Pelvic Girdle
- is formed from the 2 hips bones (ossa coxae)
- each os coxa is composed of 3 bones that are fused todether in the adult
- the bones are the ilium, iscium and pubis
Features on pelvic bones
- sciatic notch: located on the posterior side of the illium, just inferior to the posterior inferior iliac spine; the sciatic nerve passes through this
- obturator foramen: (to occlude or close up) located anterior to ischial tuberosity; large hole under the acetabulum
- acetabulum: (shallow vinegar cup) a fossa located on the lateral surface of each coxal bone and point where the lower limb articulates with the girdle
Structure of the pelvis
The full pelvis includes the ossa coxae and the sacrum of the vertebral column
- sacroiliac joint: formed by the junction of the auricular surface of the coxal bone and one articular surface of te sacrum
- true pelvis: opening to the true pelvis is the pelvic inlet (brim) and the inferior opening is the pelvic outlet
Male vs female pelvis
- Position of the iliac bones: male (taller), female (wider)
- WIdth of the pelvic inlet and outlet: male (heart shaped), female (circular)
- Depth of the pelvis: male (deep), female (shallow)
- Sacrum: male (V shaped), female (wedge shaped)
Tarsals
Talus, calcaneus, navicular, cuboid, cuneiforms (3) - medial, intermediate, lateral
Children that never march in line…
Articulations
area where bones come together, the joints
Joint Classification
Joints may be classified according to structure
- fibrous
- cartilaginous
- synovial
Fibrous Joints
- Structure: composed of dense fibrous connective tissue; ligaments, strands of dense fibrous tissue hold the bones close together
- Motion: little or no movement is possible between adjoining bones
Fibrous Joints
Types
- Suture: binds skull bones together; located: frontal and parietal bones
- Syndesmosis: hold long bones together along their length; bands of fibrous connective tissue for the connections; located: distal tibia and distal fibula
- Gomphosis: periodontal ligaments bind teeth to bone; located: teeth and mandible
Cartilage Joints
- Structure: cartilage forms the connection between joints
- Motion: limited or slight movement is possible in the joints
Cartilage Joints
Types
- Symphysis: a pad of fibrocartilage is present between bones; located: between pelvic bones
- Synchondrosis: bands of hyaline cartilage are between bones; located: growth plates
Synovial Joints
- Joint capsule consists of:
- outer fibrous coat: composed of dense irregular connective tissue and is continuous with the fibrous layer of the periosteum that covers the bone
- inner synovial membrane: lines the joint cavity except over the articular cartilage and articular disks; membrane produces synovial fluid
Synovial Joints
synovial fluid
a thin, luberating film that covers the surface of a joint
Synovial Joints
synovial cavity
is the enclosed area of the articular surfaces where bones meet; covered by the joint capsule
Synovial Joint
articular cartilage
hyaline cartilage: reduces friction; covering of articulation which provides a smooth surface where the bones meet
Synovial Joints
joint stability
synovial joints are much less stable than fibrous or cartilage joints
stability is maintained by the presence of ligaments and tendons
- ligaments: bands of fibrous connective tissue bind bones together; ligaments are outside the joint capsule and serve to stabilize; in major joints, ligaments are needed to stabilize and allow movement
- tendons: the ends of skeletal muscles form tendons which attach the muscle to bones; pass across joints, giving additional stability
Synovial Joints
special structure
present only in specific joints
- bursa
- tendon sheaths
Synovial Joints
bursa
an extension of the synovial membrane that forms a pocket, or sac that helps cushion structure
Synovial Joints
tendon sheaths
a modified bursa that extend along a tendon
Synovial Joints
articular disks
- a flat plate or pad of fibrocartilage that lies between the articular cartilages of bones and helps cushion, provide stability, and disperses synovial fluid
- circumference attached to casule and may or may not divide the joint space
Synovial Joints
accessory ligaments
ligaments about an articulation that are in addition to the joint capsule to add stability
Synovial Joints
Motion
- synovial joints allow the greatest degree of movement
- there are 2 classifications of types of motion: angular and circular
Synovial Joints
angular movements
- these involve changes in angles between bones
- flexion: bending or decreasing the angle
- extension: straightening or increasing the angle
Synovial Joints
circular movements
- these motions produce a circular or cone-shaped pattern
- rotation: movement of a bone along its length, twisting
