The Joints

Question 1

What is a joint?

Answer 1

Site where to bones meet.
Weakest part of the skeleton

Question 2

3 functional classes of joints (how moveable is each)

Answer 2

Synarthroses: immovable
Amphiarthroses: slightly moveable
Diarthroses: freely moveable

Question 3

3 strcutrual classifications of bones (material that binds + joint cavity present?) Example of each
Fibrous
Cartilaginous
Synovial

Answer 3

Fibrous: dense fibrous connective tissue, no joint cavity (skull bones)
Cartilaginous: cartilage, no joint cavity (pubic symphysis)
Synovial: hyaline cartilage, have fluid-containing joint cavity (most joints)

Question 4

6 classes of synovial joints + example

Answer 4

1. Gliding joints: metacarpals
2. Hinge joint: elbow
3. Pivot joint: radius/ulna
4. Condylar joint (biaxial movement: wrist, knuckles
5. Saddle joint: THUMB
6. Ball and socket joint: shoulder, hip

Question 5

Function of synovial fluid

Answer 5

Lubricate, reduce friction in joint

Question 6

Nerve/blood supply in joints: rich or low?

Answer 6

Rich in both, really hurts to break a joint/dislocate

Question 7

Bursae: location, contents, purpose

Answer 7

Between bones, contain synovial fluid, to prevent rubbing of bones together
Bursitis: inflammation of the bursa

Question 8

Tendon sheath: location, contents, purpose

Answer 8

around tendons, filled with synovial fluid, to reduce tendon friction

Question 9

Articular fat pads: purpose

Answer 9

cushioning

Question 10

Articular discs: AKA, purpose

Answer 10

AKA menisci, improve fit of joints, reduce wear/tear

Question 11

3 stabilizing factors of joints

Answer 11

Shape of articular surface: shallow shoulder vs deep hip
Ligament #/location: lots of ligaments in knee/ankle/hip
Muscle tone (keeping tendons taut across joint): rotator cuff in shoulder

Question 12

Easiest joint to dislocate (what part pops out of place)

Answer 12

Temporomandibular joint (mandibular condyle)

Question 13

Hardest (moving) joint to dislocate (how many ligaments)

Answer 13

Hip joint (coxal joint): 3 strong ligaments-ilium/ischium
Commonly disloacted in car accidents

Question 14

Joint example of sacrificing stability for mobility (name of ligament that helps with stability)

Answer 14

Shoulder (gelnohumeral) - coracohumeral

Question 15

Knee joint: how many joints total, names

Answer 15

3 joints
Femoropatellar joint
Lateral tibiofemoral joint
Medial tibiofemoral joint

Question 16

LCL: full name, attached to meniscus?, prevents?

Answer 16

Lateral collateral ligament, not attached to meniscus, prevents lateral buckling

Question 17

MCL: full name, attached to meniscus?, prevents?

Answer 17

Medial collateral ligament, attached to meniscus prevents medial buckling

Question 18

ACL: full name, attached to?, prevents?, crosses over with?

Answer 18

Anterior cruciate ligament, attached to anterior tibia, prevents tibia from sliding anteriorly, crosses over with PCL

Question 19

PCL: full name, attached to?, prevents?

Answer 19

Posterior cruciate ligament, attached to posterior tibia, prevents tibia from sliding posteriorly

Question 20

lateral blow to knee causes which 3 ligaments to commonly tear?

Answer 20

Medial collateral ligament, medial meniscus, Anterior cruciate ligament (ACL)
though all 3 not so common anymore