joints

Question 1

What are joints?

Answer 1

Joints, or articulations, are the point where two or more bones meet.

Question 2

What are the two main 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 determines the function of a joint?

Answer 4

The structure of the articulation determines the function.

Question 5

What is structural classification of joints based on?

Answer 5

The physical structure of the joint.

Question 6

What are fibrous joints?

Answer 6

Joints joined by fibrous connective tissue with no joint cavity.

Question 7

Give an example of a fibrous joint.

Answer 7

Sutures between cranial bones.

Question 8

What are cartilaginous joints?

Answer 8

Joints where two bones are joined by cartilage and lack a joint cavity.

Question 9

Provide examples of cartilaginous joints.

Answer 9

• Intervertebral discs
• Pubic symphysis

Question 10

What characterizes synovial joints?

Answer 10

They have a joint cavity, a joint capsule, and are filled with synovial fluid.

Question 11

What are the three functional classifications of joints?

Answer 11

• Synarthrotic (immovable)
• Amphiarthrotic (slightly movable)
• Diarthrotic (freely movable)

Question 12

What does synarthrotic mean?

Answer 12

The joint is immovable.

Question 13

What does amphiarthrotic mean?

Answer 13

The joint is slightly movable.

Question 14

What does diarthrotic mean?

Answer 14

The joint is freely movable.

Question 15

What are the characteristics of fibrous joints?

Answer 15

• Joined by connective tissue
• Lack a joint cavity
• Mostly immovable

Question 16

What is a gomphosis?

Answer 16

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

Question 17

What are synchondroses?

Answer 17

Joints where the bones are connected by hyaline cartilage and are synarthrotic.

Question 18

Provide an example of a synchondrosis.

Answer 18

Joint between the 1st rib and the sternum.

Question 19

What are symphyses?

Answer 19

Joints where fibrocartilage connects the bones, allowing slight movement.

Question 20

Give examples of symphyses.

Answer 20

• Intervertebral discs
• Pubic symphysis

Question 21

What is the role of articular cartilage in synovial joints?

Answer 21

Acts as a cushion to withstand compression of the bone ends.

Question 22

What is synovial fluid?

Answer 22

A viscous fluid that reduces friction between cartilages and minimizes wear.

Question 23

What are capsular ligaments?

Answer 23

Expansions of the fibrous layer of the capsule that reinforce synovial joints.

Question 24

What are the types of movements at synovial joints?

Answer 24

• Gliding
• Angular movements
• Rotation
• Special movements

Question 25

What is flexion?

Answer 25

Decreasing the angle between two bones.

Question 26

What is extension?

Answer 26

Increasing the angle between two bones.

Question 27

What is abduction?

Answer 27

Movement away from the midline of the body.

Question 28

What is adduction?

Answer 28

Movement toward the midline of the body.

Question 29

What is circumduction?

Answer 29

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

Question 30

What is rotation?

Answer 30

Turning movement of a bone around its long axis.

Question 31

What is opposition?

Answer 31

Movement at the first metacarpophalangeal joint allowing the thumb to touch other fingers.

Question 32

What is dorsiflexion?

Answer 32

Pulling the toes and the top of the foot upwards.

Question 33

What is plantarflexion?

Answer 33

Pointing the toes downwards.

Question 34

What is inversion?

Answer 34

Turning the sole of the foot medially.

Question 35

What is eversion?

Answer 35

Turning the sole of the foot laterally.

Question 36

What is protraction?

Answer 36

Movement of a body part forward in a transverse plane.

Question 37

What is retraction?

Answer 37

Movement of a body part backward in a transverse plane.

Question 38

What are the six types of synovial joint shapes?

Answer 38

* Plane joint * Hinge joint * Pivot joint * Condylar joint * Saddle joint * Ball and socket joint

Question 39

What is the largest joint in the body?

Answer 39

The knee joint.

Question 40

What are the three actual articulations of the knee joint?

Answer 40

* Tibiofemoral joint * Patellofemoral joint * Menisci

Question 41

What type of joint is the tibiofemoral joint?

Answer 41

A hinge joint.

Question 42

What is a bursa?

Answer 42

A flattened fibrous sac containing synovial fluid designed to reduce friction.

Question 43

What is bursitis?

Answer 43

Inflammation of the bursa due to trauma or overuse.

Question 44

What do menisci do in the knee joint?

Answer 44

Help deepen the joint cavity, prevent rocking of the femur, and absorb shock.

Question 45

What is a patellar ligament?

Answer 45

Continuation of the thick tendon attaching the Quadriceps muscle group to the patella.

Question 46

What are the extracapsular ligaments of the knee?

Answer 46

* Tibial collateral ligament (M-C-L) * Fibular collateral ligament (L-C-L)

Question 47

What are the intracapsular ligaments of the knee?

Answer 47

* Anterior cruciate ligament (A-C-L) * Posterior cruciate ligament (P-C-L)

Question 48

What does the anterior cruciate ligament prevent?

Answer 48

Prevents forward sliding of the tibia on the femur.

Question 49

What does the posterior cruciate ligament prevent?

Answer 49

Prevents the tibia from moving posteriorly relative to the femur.

Question 50

What is the function of the anterior cruciate ligament?

Answer 50

Prevents forward sliding of the tibia on the femur and resists hyperextension of the knee.

Question 51

Name one of the anterior ligaments of the knee.

Answer 51

Anterior cruciate ligament.

Question 52

What are the two intracapsular ligaments that cross deep inside the knee joint cavity?

Answer 52

Anterior cruciate ligament and posterior cruciate ligament.

Question 53

Name two extracapsular ligaments of the knee.

Answer 53

Tibial collateral ligament and fibular collateral ligament.

Question 54

What role do muscles and their tendons play in knee joint protection?

Answer 54

They reinforce the knee joint capsule and attach muscle to bone.

Question 55

Which muscle group’s tendons help prevent hyperextension of the knee?

Answer 55

Hamstring muscle group.

Question 56

What happens when the femoral condyles roll across the tibial condyles?

Answer 56

The femur spins medially on the tibia, locking the joint.

Question 57

What muscle unlocks the knee joint?

Answer 57

Popliteus muscle.

Question 58

What is the unhappy triad?

Answer 58

Injury to the ACL, MCL, and medial meniscus.

Question 59

True or False: The knee is most susceptible to sports injuries due to its reliance on non-articular factors for stability.

Answer 59

True.

Question 60

Fill in the blank: Joints are classified _______.

Answer 60

[structurally and functionally].

Question 61

What type of joints are generally immovable?

Answer 61

Fibrous joints.

Question 62

What are synovial joints characterized by?

Answer 62

They are freely movable and have a joint cavity, articular capsule, and synovial fluid.

Question 63

What is the large and complex joint referred to as?

Answer 63

Tibiofemoral joint.

Question 64

What encloses the lateral and posterior aspects of the knee?

Answer 64

Knee joint capsule.

Question 65

What occurs to the femur when the knee is locked straight?

Answer 65

The femur rotates medially on the tibia.

Question 66

What ligaments enclose the anterior aspect of the knee joint?

Answer 66

Capsular ligaments.

Question 67

What is a common mechanism of injury for the ACL during sports?

Answer 67

Quickly changing direction while running.