Joints

Question 1

How are joints classified?

Answer 1

Structurally and by function

Question 2

What are the 3 different types of joints? Structurally and by function. Explain each one and give one example.

Answer 2

1. Fixed or fibrous - immovable. Ex: sutures in skull.
2. Slightly movable or cartilaginous - slight movement. Ex: adjacent vertebrae
3. Freely movable or synovial - limited by muscles, etc. Ex: shoulder joint.

Question 3

Describe the different types of joints.

Answer 3

1. Ball-and-socket. Hip-joint and shoulder-joint. Synovial.
2. Hinge. Elbow, knee, ankle.
3. Pivot. Between atlas (C1) and axis (C2). Rotate.
4. Gliding. Side to side, and back and forth. Carpals, tarsals, sternum and clavicle, scapula and clavicle.
5. Saddle. Only one in thumb. “”

Question 4

State parts of synovial joints and describe each one.

Answer 4

a) Capsule - fibrous capsule holds bones together.
b) Synovial membrane - inner layer of capsule - supplied with blood capillaries.
c) Synovial fluid - secreted by synovial membrane - provides nourishment, removes microorganisms and helps keeping articulating surfaces from touching each other.
d) Articular cartilage - covers Diaphysis.
e) Articular discs - divide synovial cavity into 2 cavities.
f) Bursae - little sacs of synovial fluid that prevent friction between bone and ligament.
g) Accessory ligaments - hold bones together in many joints.

Question 5

What are the different movements at the joints?

Answer 5

1. Flexion - decrease angle
2. Extension - increase angle
3. Abduction - away from midline
4. Adduction - towards midline
5. Rotation - around its long axis