7.7

Question 1

What are the main characteristics of fibrous joints, cartilaginous joints, and synovial joints?

Answer 1

Fibrous joints are immovable bc the bones are firmly united by fibrous tissue, like skull sutures.

Cartilaginous joints allow slight movement, such as intervertebral disks.

Synovial joints, like the shoulder and stifle, are freely movable and have articular surfaces, cartilage, a fluid-filled cavity, and ligaments for stability.

Question 2

What is synovial fluid and why is it important to the functioning of a synovial joint?

Answer 2

Synovial fluid is produced by the lining of the joint capsule. It lubricates synovial joints, is transparent, and has the viscosity of a medium-weight motor oil. It can be aspirated and analyzed to help diagnose some disorders

Question 3

What is the difference between a tendon and a ligament?

Answer 3

Tendons join muscles to bones. Ligaments join bones to other bones.

Question 4

Make the following joint movements with your own body: abduction, adduction, circumduction, extension, flexion, and rotation.

Answer 4

adduction: movement of an extremity toward the median plane

abduction: movement away from the median plane (hold your arm out with your palm down and move it
so your palm is up), abduct=take away

circumduction: movement of an extremity so that the distal end moves in a circle (extending your arm and moving your hand in a circle)

extension: increases the angle b/w two bones, straightening a bent (or flexed) elbow joints extends the joint

flexion: decreases the angle b/w two bones

rotation: twisting movement of part on its own axis

Question 5

Name some examples of each of these kinds of synovial joint:
1. Ball-and-socket joint
2. Gliding joint
3. Hinge joint
4. Pivot join

Answer 5

1. Ball-and-socket joint: shoulder and hip joints
2. Gliding joint: carpus and tarsus
3. Hinge joint: elbow joint and atlanto occipital joint (between the skull (occipital bone) and first cervical vertebra (atlas))
4. Pivot joint: atlantoaxial joint