Introduction And Classification Of Joints Based On Structural

Question 1

What is a joint?

Answer 1

A connection between 2 or more bones

Question 2

What are the primary functions of joints?

Answer 2

Movement and stability

Examples include movement of limbs and stability found in the bones of the skull.

Question 3

What are the characteristics of fibrous joints?

Answer 3

Bone ends united by fibrous tissue, immovable, no joint cavity

Question 4

List the subtypes of fibrous joints.

Answer 4

• Sutures
• Syndesmoses
• Gomphosis

Question 5

What are sutures?

Answer 5

Immovable joints peculiar to the skull

Question 6

Name the types of sutures based on the shape of bony margins.

Answer 6

• Serrate suture
• Denticulate suture
• Plane suture
• Squamous suture
• Wedge and Groove suture

Question 7

What is the anterior fontanelle used for in infants?

Answer 7

To judge the hydration of the infant

Question 8

What happens to fontanelles by 18 months?

Answer 8

They become bone

Question 9

What are synostoses?

Answer 9

Fused skull bones in middle age

Question 10

What characterizes syndesmoses?

Answer 10

Permits slight movement

Question 11

Give an example of an interosseous membrane.

Answer 11

Between the tibia and fibula in the leg, or between radius and ulna in the forearm

Question 12

What are gomphoses?

Answer 12

Immovable joints where a cone-shaped peg fits into a socket by fibrous tissue

Question 13

What are the two types of cartilaginous joints?

Answer 13

• Synchondroses
• Symphyses

Question 14

Describe primary cartilaginous joints (synchondroses).

Answer 14

Connecting tissue is hyaline cartilage, immovable and strong

Question 15

Provide an example of a primary cartilaginous joint.

Answer 15

Epiphyseal (growth) plate

Question 16

What defines secondary cartilaginous joints (symphyses)?

Answer 16

Slightly movable, ends covered with hyaline cartilage and united by a disc of fibrocartilage

Question 17

List examples of secondary cartilaginous joints.

Answer 17

• Pubic symphysis
• Intervertebral joints
• Manubriosternal joint

Question 18

What is a synovial joint?

Answer 18

A joint that allows for free movement

Question 19

What is the function of the synovial cavity?

Answer 19

Allows a joint to be freely movable

Question 20

What covers the articular surfaces in a synovial joint?

Answer 20

Articular cartilage

Question 21

What is the composition of the articular capsule?

Answer 21

• Inner synovial membrane
• Outer fibrous capsule

Question 22

What does the synovial membrane secrete?

Answer 22

Synovial fluid

Question 23

What are the functions of synovial fluid?

Answer 23

• Reducing friction
• Absorbing shocks
• Supplying oxygen and nutrients
• Removing carbon dioxide and metabolic wastes

Question 24

What are the classifications of synovial joints according to the number of articulating bones?

Answer 24

A. Simple - only 2 bones enter in articulation.
B. Complex - joint is divided into 2 compartments by articular disc or meniscus.
C. Compound - more than 2 bones enter in articulation.

Question 25

What are the classifications of synovial joints according to the axis of movements?

Answer 25

A. UNIAXIAL - around one axis. B. BIAXIAL - around two axes. C. MULTIAXIAL - around three axes.

Question 26

What are the types of synovial joints according to the shape of articulating surfaces?

Answer 26

Hinge joints, Pivot joints, Bicondylar joints, Ellipsoid joints, Saddle joints, Ball-and-socket joints, Plane joints.

Question 27

What are the characteristics of hinge joints?

Answer 27

Articular surfaces are pulley-shaped. Examples: elbow, ankle, interphalangeal joints. UNIAXIAL – transverse axis. Movements: Flexion, Extension.

Question 28

What defines a pivot joint?

Answer 28

Rounded surface of bone articulates with the ring formed by the 2nd bone ligament. Examples: proximal radioulnar joint, atlanto-axial joint. UNIAXIAL - around vertical axis.

Question 29

What are the characteristics of condylar joints?

Answer 29

Articular surfaces include two distinct condyles fitting into reciprocally concave surfaces. Modified hinge joint. Examples: knee joint, TMJ.

Question 30

What defines an ellipsoid joint?

Answer 30

One articular surface is convex & elliptical, the other is concave & reciprocally curved. Examples: Radiocarpal joint, Metacarpophalangeal joints. Movements: Flexion, extension, adduction, abduction & circumduction.

Question 31

What are the characteristics of saddle joints?

Answer 31

Articular surface of one bone is saddle-shaped, and the other fits into the saddle. Examples: 1st carpometacarpal joint, Sternoclavicular joint. Movements: Flexion, extension, adduction, abduction & circumduction.

Question 32

What defines a ball-and-socket joint?

Answer 32

Articular surfaces include a globular head fitting into a cup-shaped socket. Examples: Shoulder joint. Multiaxial - around transverse, vertical & AP.

Question 33

What are the characteristics of plane (gliding) joints?

Answer 33

Articular surfaces are more or less flat. Examples: Intercarpal & Intertarsal joints, joints of articular processes of vertebrae.