7.4: Introduction to the Musculoskeletal System

Question 1

What are the four structural classifications of joints?

Answer 1

• Bony
• Fibrous
• Cartilaginous
• Synovial

Question 2

What are the three structural classifications of joints?

Answer 2

• Synarthrosis
• Amphiarthrosis
• Diarthrosis

Question 3

What are gliding joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 3

• Two smooth surfaces that slide over one another to produce small, gliding movements
• Non axial
• E.g. metacarpals of hand

Question 4

What are hinge joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 4

• Cylinder fits into trough of another
• Uni-axial
• E.g. elbow

Question 5

What are pivot joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 5

• Cylindrical bone rotates inside another bone that wraps around it
• Uniaxial
• E.g. radius and ulna

Question 6

What are condylar joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 6

• Oval shaped articular surface fits into bowl-like depression on other
• Bi-axial (sagittal and coronal)
• E.g. knuckle (in fact, condyle means knuckle)

Question 7

What are saddle joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 7

• Each articular surface has both concave and convex surface
• Bi-axial (sagittal and coronal)
• E.g. Carpometacarpal joint of the thumb

Question 8

What are ball-and-socket joints? Are they non-axial, uni-axial, bi-axial, or multi-axial (give an example)?

Answer 8

• Spherical ball articulates with cup-shaped socket
• Multi-axial
• E.g. shoulder

Question 9

What is the difference between concentric/eccentric/isometric muscle movements?

Answer 9

Concentric: shorten
Eccentric: lengthen
Isometric: same length