Class 14 - Selected Diarthroses

Question 1

Temporomandibular joint + 2 supporting ligaments

Answer 1

Jaw. Articulation of condyle of mandible with the mandibular fossa of the temporal bone.

Synovial cavity divided into superior and inferior chambers by an ARTICULAR DISC.

1. Lateral ligament - Prevents posterior displacement of mandible
2. Sphenomandibular ligament - Medial side

Question 2

Glenohumeral (humeroscapular) joint + glenoid labrum

Answer 2

Shoulder. Hemispherical head of humerus articulates with glenoid cavity of scapula (ball-and-socket)

Most freely mobile joint in body

Shallow glenoid cavity and loose joint capsule = more freedom, less stability

Glenoid labrum - fibrocartilage ring that deepens glenoid cavity

Question 3

5 tendons of the shoulder joint

Answer 3

5 tendons:
1. Long head tendon of biceps brachii
(2-5 fuse to form rotator cuff)
2. Supraspinatus
3. Infraspinatus
4. Teres minor
5. Subscapularis

Fused to joint capsule in all sides except inferior

Question 4

5 ligaments of the shoulder joint

Answer 4

1-3. Glenohumeral ligaments
4. Coracohumeral ligament
5. Transverse humeral ligament

Question 5

4 bursa of the shoulder joint

Answer 5

1. Subdeltoid
2. Subacromial
3. Subcoracoid
4. Subscapular

Question 6

Most common shoulder dislocation

Answer 6

Anterior dislocation (95% of cases)

Occur when arm is abducted and receives a blow from above.

Dislocation may cause nerve and blood vessel damage.

Question 7

The 2 elbow joints + Olecranon bursa

Answer 7

Humeroulnar joint - trochlea of humerus joins trochlear notch of ulna

Humeroradial joint - capitulum of humerus meets head of radius

Both articulations enclosed in ONE joint capsule.

Olecranon bursa - On posterior side of elbow. Eases movements of tendons.

Question 8

2 ligaments of elbow joint + 1 of elbow region

Answer 8

1. Radial (lateral) collateral ligament
2. Ulnar (medial) collateral ligament

^ Both restrict side-to-side motions.

A. Proximal radioulnar joint - head of radius fits into radial notch of ulna. Held in place by annular ligament encircling radial head. Pivot joint

Question 9

Coxal joint + 2 stability features

Answer 9

Hip joint. Head of femur inserts into acetabulum of hip bone

Stability features:
1. DEEP socket
2. fibrocartilage acetabular labrum

Dislocations RARE

Question 10

Ligaments associated with the hip joint (5)

Answer 10

1. Iliofemoral ligament - anterior side
2. Pubofemoral ligaments - anterior side
3. Ischiofemoral ligament - posterior side
   (1-3 twist and pull head of femur when standing)
4. Transverse acetabular ligament - bridges gap on inferior margin of acetabular labrum
5. Round ligament - Fovea capitis to acetabulum. Contains artery that supplies ONLY blood supply to head of femur

Question 11

Tibiofemoral joint, patellofemoral joint

Answer 11

Knee joint.

Tibiofemoral joint - Hinge between femur and tibia. Largest and MOST COMPLEX diarthrosis.

Flexion and extension, slight rotation and lateral gliding when knee flexed

Patellofemoral joint - patella and patellar ligament articulate with femur; gliding joint

Joint capsule encloses only the lateral and posterior knee aspects (anterior covered by patellar ligament)

Question 12

2 stabilizing tendons of the knee joint + additional structures

Answer 12

1. Quadriceps tendon - anterior
2. Semimembranous muscle (of hamstring) - posterior

Additional structures:
13 bursae

Question 13

Most common knee injuries (2) and why they heal slowly

Answer 13

1. Menisci
2. Anterior cruciate ligament (ACL)

Heal slowly due to lack of blood supply.
Highly vulnerable to rotational and horizontal stress

Question 14

Arthroscopy + 2 benefits + healing time

Answer 14

Procedure in which interior of joint (usually knee) is viewed with a pencil-thin arthroscope inserted through a small incision

1. Less tissue damage than conventional surgery
2. Faster recovery

ACL repair takes ~9 months to heal

Question 15

Talocrural joint

Answer 15

Ankle joint. Includes two articulations: medial joint between tibia and talus, lateral joint between fibula and talus

Articulations enclosed in one joint capsule
Malleoli of tibia and fibula overhang talus on either side, preventing side-to-side motion

Question 16

3 ligaments + 1 tendon of the ankle joint

Answer 16

1. Anterior/posterior tibiofibular ligaments - bind tibia to fibula
2. Multipart medial (deltoid) ligament - bind tibia to foot on medial side
3. Multipart lateral (collateral) ligament - binds fibula to the foot on the lateral side
4. Calcaneal (Achilles) tendon - extends from the calf muscle to the calcaneus; plantarflexes foot and limits dorsiflexion.

Question 17

Arthritis + 2 types + treatment

Answer 17

A broad term for pain and inflammation of joints; most common crippling disease

1. Osteoarthritis - most common form; from wear and tear. Articular cartilage degenerates; bones spurs develop; bone sounds called crepitus.
2. Rheumatoid arthritis - causes by autoimmune attack. Synovial fluid enzymes degrade articular cartilage, joints ossify

Arthroplasty - replacement of diseased joints with artificial joint processes called prosthesis

Question 18

Ankylosis

Answer 18

Solidly fused, immobilized joint as a result of joint ossification from rheumatoid arthritis

Question 19

Posterior popliteal region of knee supporting ligaments (4)

Answer 19

Extracapsular ligaments:
1. Fibular (lateral) collateral ligament
2. Tibial (medial) collateral ligament

Intracapsular ligaments:
3. Anterior cruciate ligament (ACL)
4. Posterior cruciate ligament (PCL)

Question 20

Additional structures associated with the knee (2)

Answer 20

1. Lateral and medial menisci
2. Transverse ligament (joins menisci)