Skeletal System Joints

Question 1

What are joints, or articulations?

Answer 1

The point where two or more bones meet

Question 2

What are the two primary functions of joints?

Answer 2

• Permit mobility
• Offer stability

Question 3

Why are joints considered the weakest part of the skeleton?

Answer 3

They represent a ‘break’ in the continuum of the bones and are prone to wearing out

Question 4

What are the two classification systems for joints?

Answer 4

• Structural classification
• Functional classification

Question 5

What is structural classification of joints based on?

Answer 5

The physical structure of the joint

Question 6

What type of joint is characterized by two bones joined by fibrous connective tissue with no joint cavity?

Answer 6

Fibrous joint

Question 7

Give an example of a fibrous joint.

Answer 7

Sutures between the cranial bones

Question 8

What type of joint is formed when two bones are joined by cartilage and lack a joint cavity?

Answer 8

Cartilaginous joint

Question 9

Provide an example of a cartilaginous joint.

Answer 9

• Intervertebral discs
• Pubic symphysis

Question 10

What is a synovial joint?

Answer 10

A joint that has a joint cavity, a joint capsule, and is filled with synovial fluid

Question 11

What is the functional classification of a joint that is immovable?

Answer 11

Synarthrotic joint

Question 12

What does an amphiarthrotic joint allow?

Answer 12

Slight movement

Question 13

What is an example of a diarthrotic joint?

Answer 13

• Knee joint
• Shoulder joint
• Hip joint

Question 14

What characterizes fibrous joints?

Answer 14

Bones are joined by connective tissue and lack a joint cavity

Question 15

What is a gomphosis?

Answer 15

A peg-in-socket fibrous joint that ‘nails’ the tooth in the bony alveolar socket

Question 16

What type of cartilage connects bones in synchondroses?

Answer 16

Hyaline cartilage

Question 17

What are symphyses joints characterized by?

Answer 17

Fibrocartilage that is compressible and acts as a shock absorber

Question 18

What type of joint allows for freely movable articulation?

Answer 18

Synovial joint

Question 19

What is the role of articular cartilage in synovial joints?

Answer 19

Acts as a cushion to withstand compression of bone ends

Question 20

What is synovial fluid derived from?

Answer 20

Filtration from blood flowing through capillaries in the synovial membrane

Question 21

What type of movements occur at synovial joints?

Answer 21

• Gliding
• Angular
• Rotational
• Special movements

Question 22

What is flexion?

Answer 22

A movement that decreases the angle between two bones

Question 23

What is the opposite of flexion?

Answer 23

Extension

Question 24

What does abduction refer to?

Answer 24

Movement away from the midline of the body

Question 25

What is circumduction?

Answer 25

Movement where the distal part of a limb moves in circles while the proximal part remains stationary

Question 26

What is rotation in the context of joint movements?

Answer 26

Turning movement of a bone around its long axis

Question 27

What is opposition of the thumb?

Answer 27

Movement that allows the thumb tip to touch each of the other fingers

Question 28

Define dorsiflexion.

Answer 28

Pulling the toes and the top of the foot upwards

Question 29

What is plantarflexion?

Answer 29

Pointing the toes downwards

Question 30

What does inversion refer to?

Answer 30

Turning the sole of the foot medially

Question 31

What is the shape of the knee joint?

Answer 31

Complex with a single joint cavity involving three articulations

Question 32

What type of joint is the Tibiofemoral joint?

Answer 32

Hinge joint

Question 33

What is the function of bursae in joints?

Answer 33

Reduce friction between adjacent structures during joint activity

Question 34

What are menisci?

Answer 34

C-shaped fibrocartilages that help deepen the joint cavity and stabilize the knee

Question 35

What are the capsular ligaments of the knee?

Answer 35

* Patellar ligament * Medial patellar retinaculum * Lateral patella retinaculum

Question 36

What are extracapsular ligaments?

Answer 36

Ligaments located outside the joint capsule

Question 37

Name two extracapsular ligaments of the knee.

Answer 37

* Tibial collateral ligament (MCL) * Fibula collateral ligament (LCL)

Question 38

What are intracapsular ligaments?

Answer 38

Ligaments located inside the joint capsule

Question 39

What are the names of the cruciate ligaments?

Answer 39

* Anterior cruciate ligament (ACL) * Posterior cruciate ligament (PCL)

Question 40

What does the ACL prevent?

Answer 40

Forward sliding of the tibia on the femur and resists hyperextension of the knee

Question 41

What does the PCL prevent?

Answer 41

The tibia from moving posteriorly relative to the femur

Question 42

What are the two main ligaments located inside the knee joint cavity?

Answer 42

Anterior cruciate ligament (ACL) and Posterior cruciate ligament (PCL) ## Footnote These ligaments are named based on their attachment points on the tibia.

Question 43

What does the anterior cruciate ligament (ACL) prevent?

Answer 43

Forward sliding of the tibia on the femur and resists hyperextension of the knee ## Footnote The ACL attaches to the anterior tibial plateau.

Question 44

What is the role of the posterior cruciate ligament (PCL)?

Answer 44

Prevents the tibia from moving posteriorly relative to the femur ## Footnote The PCL attaches to the posterior tibial plateau.

Question 45

Name two extracapsular ligaments of the knee.

Answer 45

Tibial collateral ligament (MCL) and Fibular collateral ligament (LCL) ## Footnote These ligaments are located outside the articular capsule.

Question 46

What reinforces the knee joint capsule besides ligaments?

Answer 46

Muscles and their tendons ## Footnote Tendons are dense connective tissues containing collagen that attach muscle to bone.

Question 47

What happens to the femur when the knee moves from flexion into extension?

Answer 47

The femoral condyles roll across the tibial condyles and the femur rotates medially on the tibia ## Footnote This rotation happens until the ligaments are twisted and taut.

Question 48

What muscle unlocks the knee joint?

Answer 48

Popliteus muscle ## Footnote This muscle allows the femur to rotate laterally on the tibia.

Question 49

What is known as 'the unhappy triad' in knee injuries?

Answer 49

Injury to the ACL, MCL, and medial meniscus ## Footnote These injuries often occur together due to their anatomical connections.

Question 50

True or False: The knee joint capsule is only protected by ligaments.

Answer 50

False ## Footnote The knee joint capsule is also reinforced by muscles and their tendons.

Question 51

What type of joint are synovial joints classified as?

Answer 51

Freely movable joints (diarthrotic) ## Footnote They are the most structurally complex joints and often the most commonly dysfunctional.

Question 52

Fill in the blank: Fibrous joints are generally _______.

Answer 52

immovable ## Footnote They can be classified as synarthrotic or amphiarthrotic depending on the length of fibers.

Question 53

What are the three types of joint classifications mentioned?

Answer 53

Fibrous, Cartilaginous, and Synovial ## Footnote Each type has different characteristics and degrees of movement.

Question 54

What is the main function of the ligaments in the knee?

Answer 54

Attach bone to bone and provide stability ## Footnote They play a crucial role in maintaining joint integrity.

Question 55

What can cause an ACL injury without a direct blow to the knee?

Answer 55

Quick changes in direction or twisting a hyperextended knee ## Footnote This is common in sports like soccer or netball.

Question 56

What happens when a lateral force is applied to an extended knee?

Answer 56

It can tear the MCL and medial meniscus, as well as the ACL ## Footnote This is often seen in sports-related injuries.