Joints- Structure, function and movement

Question 1

What is a joint?

Answer 1

A joint is the point of contact between two bones.

The specific structure of a joint determines its function, dictating the type and range of movement it allows.

Question 2

What is the primary function of cartilage in a joint?

Answer 2

The primary function of cartilage is to protect bones from friction where they meet at a joint.

The two types of cartilage found in joints are hyaline cartilage (articular cartilage) and fibrocartilage.

Question 3

What are ligaments?

Answer 3

Ligaments are tough, elastic bands of connective tissue that connect bones together.

Their four main functions are stabilizing joints, limiting movements, strengthening joints, and preventing dislocations.

Question 4

What is the primary role of a bursa in a joint?

Answer 4

A bursa is a fluid-filled sac that acts as a cushion to reduce friction and tension around joints.

It helps between bones and soft tissues or between bones and tendons.

Question 5

What are menisci?

Answer 5

Menisci are C-shaped pieces of cartilage in the knee.

Their three key functions are acting as shock absorbers, transmitting weight between bones, and providing stability to the knee.

Question 6

How are joints classified?

Answer 6

Joints are classified by a structural system and a functional system.

The structural classification is based on tissue composition (fibrous, cartilaginous, synovial), while the functional classification is based on the degree of movement allowed (synarthroses, amphiarthroses, diarthroses).

Question 7

What is a syndesmosis?

Answer 7

A syndesmosis is a slightly movable (amphiarthrotic) joint connecting bones with ligaments or a strong membrane.

Question 8

What are sutures?

Answer 8

Sutures are immovable (synarthrotic) joints found only in the cranium.

Question 9

What is a gomphosis?

Answer 9

A gomphosis is an immovable joint (synarthrosis) specifically referring to the fibrous joint that anchors a tooth root in its socket

Question 10

What defines a primary cartilaginous joint (synchondrosis)?

Answer 10

A primary cartilaginous joint connects bones with hyaline cartilage.

They are classified as primary because they only contain hyaline cartilage, examples include the epiphyseal (growth) plate.

Question 11

What are the key characteristics of synovial joints?

Answer 11

Synovial joints are freely moveable (diarthroses) and are considered the body’s main functional joints.

They contain key components including articular cartilage, a joint capsule, a joint cavity filled with synovial fluid, a synovial membrane, and ligaments.

Question 12

What are the three components of a lever system in the body?

Answer 12

The three components are the fulcrum, the resistance (load), and the force (effort).

In the human body, the joints serve as fulcrums, the resistance is the weight of the body part or object being moved, and the muscle attachment provides the force.

Question 13

What components make up a joint?

Answer 13

Cartilage, synovial membrane, synovial fluid, ligaments, tendons, bursa, and meniscii

Question 14

What are the six types of synovial joints?

Answer 14

Hinge, pivot, saddle, ellipsoid, ball-and-socket, plane

Question 15

How do ligaments affect joint movement?

Answer 15

They limit movement

Question 16

What is a consequence of stretching or tearing a ligament?

Answer 16

It can make the joint unstable

Question 17

What is the mechanical function of tendons in relation to muscle force?

Answer 17

They act as a bridge to transmit muscle forces to bones and joints, allowing movement

Question 18

What is synovial fluid?

Answer 18

A thick, viscous liquid that lubricates and protects the ends of bones in joints

Question 19

What are the three main functions of synovial fluid?

Answer 19

Lubrication, nutrition, and protection

Question 20

How does the meniscus assist with weight distribution?

Answer 20

It transmits weight from one bone to another

Question 21

Sutures are an example of what structural class of joint?

Answer 21

Fibrous

Question 22

Cartilaginous joints are functionally classified as

Answer 22

Amphiarthrosis

Question 23

Primary cartilaginous joints are also known as

Answer 23

Synchondroses

Question 24

Secondary cartilaginous joints are also known as

Answer 24

Symphyses

Question 25

The pubic symphysis and intervertebral discs are examples of what specific type of cartilaginous joint

Answer 25

Secondary cartilaginous joint

Question 26

What are the four components that all synovial joints contain?

Answer 26

Articular cartilage, joint capsule, joint cavity, and synovial membrane

Question 27

Symphysis joints are secondary cartilaginous joints connected by ____ and are slightly movable

Answer 27

Fibrocartilage

Question 28

Synchondrosis joints are primary cartilaginous joints connected by ____ cartilage

Answer 28

Hyaline

Question 29

The outter layer of the articular capsule in a synovial joint is known as the ____ layer

Answer 29

Fibrous

Question 30

A saddle joint is characterized by articulating surfaces that are both ____ and _____

Answer 30

Convex and concave

Question 31

A plane joint is formed between two ____ surfaces

Answer 31

Flat

Question 32

What type of movement do pivot joints allow?

Answer 32

It allows one bone to rotate around the surface of another bone

Question 33

In a first-class leverm the ____ is located between the force and the resistance

Answer 33

Fulcrum

Question 34

In a second class lever, the ____ lies between the fulcrum and the point of force

Answer 34

Resistance

Question 35

In a third class lever, the ____ is applied between the fulcrum and the resistance

Answer 35

Force

Question 36

What is the most common class of lever found in the body?

Answer 36

Third class lever