Question

Anatomy Tutorial: Introduction to Arthrology

Answer 1

\({\bf{Classification:}}\) two methods; structure and function
Structural Classification:
- fibrous (fibrous tissue, no joint cavity)
> sutures: ex. skull bones
> syndesmoses: connected by ligament/membrane. ex: tibiofibular joint
> gomphoses: tooth + alveolar ligament

- cartilaginous (cartilage, no joint cavity)
> synchondroses: connects bones with hyaline cartilage, ex: epiphyseal plate + costal cartilage
> symphyses: connects bone/cartilage to pad. ex: intervertebral disc

- synovial (joint cavity filled w/ synovial fluid)
parts of a synovial joint:
1. articular cartilage
2. joint cavity
3. joint capsule (outer fibrous capsule and inner synovial membrane)
4. ligaments
5. synovial fluid
6. bursae
7. sometimes have fibrocartilage at the ends of bones

Functional Classification: (mnemonic: SAD)
- synarthroses (immovable)
- amphiarthroses (slightly movable, think of the prefix amphi-)
- diarthroses (movable). most appendicular joints are diarthroses.

Answer 2

\({\bf{Joint~Motions:}}\) try to remember these in pairs
- gliding
- flexion vs extension (decreasing vs increasing the joint angle)
- abduction vs adduction (moving away from reference point vs moving towards)
- circumduction (moving in a circle)
- rotation (moving in a circle about its own axis)
- supination/pronation: moving arm in the supine vs prone position
- inversion/eversion: medial rotation of foot/lateral rotation of foot
- protraction/retraction: moving mandible forward/backward
- elevation/depression: movement in the superior/inferior direction
- opposition: moving thumb so it touches the tips of the fingers

Answer 3

\({\bf{Synovial~Joints:}}\) sub-types


- plane joints: flat, ex: intercarpals/intertarsals
- hinge joints: long bone fits into a "hinge" or a depression on another bone. ex: elbow
- pivot joint: round bone fits into a depression/sleeve of bone/ligament: ex: radioulnar joint
- condyloid joint: oval end fits into a depression on the other ex. metacarpophalanges
- saddle joint: each bone has a complementary concave/convex area, ex: carpometacarpal joint
- ball and socket: spherical end fits into complementary socket ex: shoulder/hip joint

Answer 4

Adapted from Human Anatomy, Martini, et. al. 9th edition & my professor's lecture notes