Joints Flashcards
Fibrous joints
2 bones are united by fibrous tissue
Immovable
Eg. Cranial sutures, syndesmoses and gomphoses
Cartilaginous joints
Bones united by cartilage
Limited movement
Eg. Primary synchondroses (bone to rib) and secondary symphysis (pubic symphysis)
Synovial joints
Synovial capsule with: membrane, fluid and cavity
Moveable
Eg. Plane (sliding), hinge (elbow), saddle (thumb), pivot (radius), condyloid (wrist), ball and socket (hip and shoulder)
Hip joint neurovascular supply
The arterial supply- medial and lateral circumflex femoral arteries – branches of the profunda femoris artery (deep femoral artery). They anastomose at the base of the femoral neck to form a ring, from which smaller arteries arise to supply the hip joint itself. The artery to head of femur and the superior/inferior gluteal arteries provide some additional supply.
The hip joint is innervated primarily by the sciatic, femoral and obturator nerves. These same nerves innervate the knee, which explains why pain can be referred to the knee from the hip and vice versa.
Anatomical movements in the hip joint
• Flexion – iliopsoas, rectus femoris, sartorius, pectineus
• Extension – gluteus maximus; semimembranosus, semitendinosus and biceps femoris (the hamstrings)
• Abduction – gluteus medius, gluteus minimus, piriformis and tensor fascia latae
• Adduction – adductors longus, brevis and magnus, pectineus and gracilis
• Lateral rotation – biceps femoris, gluteus maximus, piriformis, assisted by the obturators, gemilli and quadratus femoris.
• Medial rotation – anterior fibres of gluteus medius and minimus, tensor fascia latae
Knee joint neurovascular supply
The blood supply to the knee joint is through the genicular anastomoses around the knee, which are supplied by the genicular branches of the femoral and popliteal arteries.
The nerve supply is by the nerves which supply the muscles which cross the joint. These are the femoral, tibial and common fibular nerves
Medial and lateral menisci
The medial and lateral menisci are fibrocartilage structures in the knee that serve two functions:
• To deepen the articular surface of the tibia, thus increasing stability of the joint.
• To act as shock absorbers by increasing surface area to further dissipate forces.
• Medial is larger
Bursa
A bursa is synovial fluid filled sac, found between moving structures in a joint – with the aim of reducing wear and tear on those structures. There are four bursae found in the knee joint:
• Suprapatellar bursa – an extension of the synovial cavity of the knee, located between the quadriceps femoris and the femur.
• Prepatellar bursa – found between the apex of the patella and the skin.
• Infrapatellar bursa – split into deep and superficial. The deep bursa lies between the tibia and the patella ligament. The superficial lies between the patella ligament and the skin.
• Semimembranosus bursa – located posteriorly in the knee joint, between the semimembranosus muscle and the medial head of the gastrocnemius.
Anatomical movements in the knee
• Extension: Produced by the quadriceps femoris, which inserts into the tibial tuberosity.
• Flexion: Produced by the hamstrings, gracilis, sartorius and popliteus.
• Lateral rotation: Produced by the biceps femoris.
• Medial rotation: Produced by five muscles; semimembranosus, semitendinosus, gracilis, sartorius and popliteus
Hip joint
Synovial
Ball and socket
Knee joint
Synovial
Hinge
Pubic joint
Cartilaginous
Symphysis
Fibula tibia joint
Fibrous
Syndesmosis ( a fibrous joint in which two adjacent bones are linked by a strong membrane or ligaments)
Cranial joint
Fibrous
Suture
Elbow joint
Synovial
Pivot