Joint Anatomy

Question 1

Arthrology

Answer 1

= Study of joints.

Question 2

What are the 3 functional classifications of joints?

Answer 2

• Synarthroses.
• Amphiarthroses.
• Diarthroses (Synovial).

Question 3

Synarthroses joint

Answer 3

• No movement
• Bones are close together & may overlock.
• Extremely strong joints (Located where movement between bones must be prevented).

Question 4

What are the 5 major types of synarthroses joint?

Answer 4

• Sutures.
• Fibrous joints.
• Gomphoses.
• Synchondroses.
• Synostoses.

Question 5

Sutures

Answer 5

Edges of bones are interlocked and bound together at the suture by dense connective tissue.
(E.g.: bones of skull).

Question 6

Fibrous joint

Answer 6

• Bone ends held together by fibrous or collagenous connective tissues.
• No synovial cavity between bone ends.
• Strong joints that inhibit movement.
• Generally synarthroses.

Question 7

Gomphoses

Answer 7

Fibrous joint.
(E.g.: Gomphoses joint binds to teeth by the bony sockets in the maxillary bone and mandible).

Question 8

Synchondroses

Answer 8

• Rigid, cartilaginous bridge between two bones.
• The epiphyseal cartilage is a synchondrosis that connects the diaphysis of a long bone with an epiphysis.
• Cartilaginous joints are connected by cartilage (Fibrocartilage or hyaline).

Question 9

Synostoses

Answer 9

Totally rigid and immovable joint created when two separate bones fuse and the boundary between them disappears
(E.g.: the epiphyseal lines of mature bones).

Question 10

Amphiarthroses

Answer 10

• Permits little movement (More than synarthroses).
• Much stronger than a freely movable joint.
• Articulating bones are connected by collagen fibres or cartilage (Cartilaginous joints).

Question 11

What are the two types of amphiarthroses?

Answer 11

• Syndesmosis.
• Symphysis.

Question 12

Syndesmosis

Answer 12

The articulating bones are connected by a ligament
(E.g.: Distal articulation between the tibia and fibula).

Question 13

Symphysis

Answer 13

The articulating bones are separated by a wedge or pad of fibrocartilage
(E.g.: Connection between the two pubic bones).

Question 14

Diarthrosis

Answer 14

• Known as a synovial joint.
• Permit a wider range of motion.
• Typically located at the ends of long bones.

Question 15

What is the purpose of synovial fluid?

Answer 15

• Nourishes & lubricates the articular cartilage.
• Shock absorber to distribute compressive forces.

Question 16

What is the purpose of articular hyaline cartilage?

Answer 16

Reduce friction during movement of the joint.

Question 17

Describe structures of a synovial joint

Answer 17

• Joint cavity/joint capsule.
• Joint (articular) capsule.
• Fibrous capsule.
• Synovial membrane.
• Synovial fluid.
• Articular hyaline cartilage.
• May contain intra-articular structures: such as Menisci (Knee), Articular disc (TMJ) & Articular labrum (Shoulder).
• Fat pad.
• Ligaments.
• Tendons.
• Fascia.
• Bursae.

Question 18

What is the purpose of synovial membrane?

Answer 18

Lines the articulatory cavity.

Question 19

What are the 6 types of synovial joints?

Answer 19

• Ball & socket.
• Hinge.
• Ellipsoid/condyloid.
• Saddle.
• Pivot.
• Plane.

Question 20

Hinge joint

Answer 20

Permits movement in one plane, usually flexion and extension (e.g: knee joint).

Question 21

Ellipsoid/Condyloid joint

Answer 21

Contains a convex surface which articulates with a concave elliptical cavity (e.g: metatarsophalangeal joint).

Question 22

Saddle joint

Answer 22

Opposing articular surfaces with a reciprocal concave-convex shape (e.g: carpometacarpal joints).

Question 23

Pivot joint

Answer 23

Allows rotation only (e.g: distal radioulnar joints).

Question 24

Plane joint

Answer 24

Articular surfaces are relatively flat, allowing the bones to glide over one another (e.g: subtalar joint).

Question 25

What are the 3 classifications of joints?

Answer 25

- Fibrous. - Cartilaginous. - Synovial.

Question 26

Cartilaginous joints

Answer 26

- Cartilage holds together bone ends. - No synovial cavity between bony ends. - Strong joints with minimal movement only. - Most are amphiarthrotic, but some are synarthrotic.

Question 27

Synovial joints

Answer 27

- Bone ends separated by synovial cavity, which allows lots of movement. - All are diarthrotic. - Predominate the limbs. - Has synovial cavity, articular cartilage, synovial capsule or articular capsule & reinforcing ligaments; same has articular discs, menisci, and bursae.

Question 28

Fat pad

Answer 28

Commonly superficial to the joint capsule, protect the articular cartilages.

Question 29

Tendons

Answer 29

May limit range of motion and provide mechanical support.

Question 30

Fascia

Answer 30

Help to maintain shape and position of muscles and allow adjacent muscles to move past each other.

Question 31

What are the 3 types of ligaments?

Answer 31

- Accessory ligaments. - Extracapsular ligaments. - Intracapsular ligaments.

Question 32

Accessory ligaments

Answer 32

Localised thickenings of the capsule.

Question 33

Extracapsular ligaments

Answer 33

Interconnect the articulating bones and pass across the outside of the capsule.

Question 34

Intracapsular ligaments

Answer 34

Help to prevent excessive movement that might damage the joint.

Question 35

Ligament

Answer 35

A tough band of connective tissue that attaches bone to bone.

Question 36

Tendon

Answer 36

A strong cord of dense connective tissue that attaches muscles to bones, to the skin, or to other muscles.

Question 37

Articulation

Answer 37

The point of contact between 2 bones (commonly called a joint).

Question 38

Cartilage

Answer 38

A resilient, strong connective tissue.