biology lesson 7.4
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Lesson 7.4
Joints – the place where bones join or articulate.
Lesson 7.4 Joints
Three categories based on ability to move:1.immovable – little to no
movment in joint ex. Sutures
2. slightly movable – some movement in joint ex. Vertebrae
3. freely movable or synovial joint – of 3 has most movement ex. Limbs, jaw
Parts of a synovial joint:
1.Articular cartilage - covers the ends of the bones
2. Synovial fluid – lubricates the joint
Parts of a synovial (freely movable) joint:1. Articular cartilage 2. Synovial fluid
3.Ligaments – hold bones together creating the joint capsule
4. Joint capsule – surrounds the joint
5. Synovial membrane – produces the synovial fluid
1. hinge joints
• ex. elbow
• like a door hinge it swings only one way
Types of synovial joints
Types of synovial joints1. hinge joints
2. Gliding joints • Ex. Carpals• one bone slides across another bone
Types of synovial joints1. Hinge joints2. Gliding joints
3. Ball and socket joints • Ex. hip• greatest range of motion• round head of one bone fits in the hollow socket of another
Types of synovial joints1. Hinge joints2. Gliding joints 3. Ball and socket joints
4. Pivot joints • ex. C1-C2 the atlas and axis
vertebrae• allows only rotation
Types of synovial joints1. Hinge joints2. Gliding joints 3. Ball and socket joints 4. Pivot joints
5. Saddle joints• Found only in the hands • ex. Thumb metacarpal to carpal• Saddle portion of one bone nestles into saddle portion of other
Types of synovial joints1. Hinge joints2. Gliding joints 3. Ball and socket joints 4. Pivot joints5. Saddle joints
6. Ellipsoid joints
• joints between metacarpals and phalanges
• move up/down and left/right
•one bone bulges and fits into indention of other bone
Joint Problems
1. Disease – mainly arthritis
2 types of arthritis
A. osteoarthritis most common joint disorder Is the deterioration of the articular cartilage usually due to age
most serious in hip joint
Joint Problems1. Disease – mainly arthritis
2 types of arthritisA. osteoarthritis
B. Rheumatoid arthritis
Autoimmune disorder Cause unknown Effects hands, ankles, knees,
fingers most often Can affect any age Controlled with medications
Joint Problems
1. Disease – mainly arthritis
2. Injury
A. Sprain most common when ligaments over
stressed and swelling and inflammation occurs
treatment is rest
Joint Problems
1. Disease – mainly arthritis 2. Injury
A. Sprain
B. Dislocation joint overstressed and bone pops out of ligament
treatment - must be relocated
Joint Problems1. Disease – mainly arthritis 2. Injury
A. SprainB. Dislocation
C. Torn Ligaments Ligament is under stress and
tears Treatment: not completely torn then rest
and it will heal completely torn will need
surgery to reattach or sub
Surgery