Articulations (Ch 9)

Question 1

What’s another name for joints?

Answer 1

articulations

Question 2

What are the functions of joints?

Answer 2

support and movement

Question 3

Joints

Answer 3

• bones articulate (come in contact) at joints
• skeletal muscles cross over joints in order to achieve movement
• more mobile = less stable
• classified by function or structure

Question 4

Functional classification of joints

Answer 4

relates to amount of movement allowed at the joint

1. Synarthrosis
2. Amphiarthrosis
3. Diarthrosis

Question 5

Synarthrosis

Answer 5

• functional classification

- immovable joint (ex. skull sutures, epiphyseal plates)

Question 6

Amphiarthrosis

Answer 6

• functional classification

- slightly movable joint (ex. pubic symphysis)

Question 7

Diarthrosis

Answer 7

• functional classification

- freely movable (ex. joints in limbs)

Question 8

Structural classification of joints

Answer 8

based on CT that binds bonds together (fibers/cartilage) and presence or absence of joint cavity

1. Fibrous
2. Cartilaginous
3. Synovial

Question 9

Fibrous

Answer 9

• structural classification of joints

- connected by fibrous CT (ex. skull sutures)

Question 10

Cartilaginous

Answer 10

• structural classification of joints

- connected by cartilage tissue (ex. pubic symphysis)

Question 11

Synovial

Answer 11

• structural classification of joints
• connected by a fluid-filled joint cavity within a capsule (ex. most joints like shoulder/elbow/knee)
• most movable (diarthrosis)

Question 12

What are the types of cartilaginous joints?

Answer 12

1. Synchondroses

2. Symphyses

Question 13

Synchondroses

Answer 13

type of cartilaginous joint where bones are joined by hyaline cartilage (ex. costochondrial joints, epiphyseal plates)

Question 14

Symphyses

Answer 14

type of cartilaginous joint where there is fibrocartilage between articulating joints (ex. intervertebral joints, public symphysis)

Question 15

What are the parts of typical synovial joints?

Answer 15

1. Articular (fibrous) capsule
2. Joint (articular) cavity
3. Synovial fluid
4. Articular (hyaline) cartilage
5. Ligaments

Question 16

Articular (fibrous) capsule

Answer 16

• synovial joint

- two parts: outer fibrous layer continuous with periosteum and inner synovial membrane that secretes synovial fluid

Question 17

Joint (articular) cavity

Answer 17

• synovial joint

- space filled with synovial fluid

Question 18

Synovial fluid

Answer 18

• synovial joint

- liquid in joint cavity/cartilages that provides lubrication

Question 19

Articular (hyaline) cartilage

Answer 19

• synovial joint

- absorbs forces on the joint and protects the bone

Question 20

Ligaments

Answer 20

• synovial joint
• connects bone to bone, strengthens joints (can be internal or external to articular capsule
• have blood supply/are innervated

Question 21

Bursae

Answer 21

*synovial joint

saclike structure with synovial fluid

Question 22

Tendon Sheaths

Answer 22

*synovial joint

wrap around tendons to reduce friction where bones/ligaments/tendons rub

Question 23

Knee Joint

Answer 23

• largest/most complex joint
• acts as hinge (may rotate slightly)
• 2 condyloid joints (lateral/medial)
• both femur and tibia have two condylar surfaces
• strong ligaments to help knee from moving wrong way (LCL, MCL, ACL, PCL)
• 12 bursa to reduce friction
• menisci made of fibrocartilage (aka articular discs) help even out weight distribution/stabilize joint
• ->prevent side to side rocking o femur on tibia

Question 24

What are the ligaments of the knee?

Answer 24

1. Lateral (fibular) Collateral Ligament (LCL)
2. Medial (tibial) Collateral Ligament (MCL)
3. Anterial Cruciate Ligament (ACL)
4. Posterior Cruciate Ligament (PCL)

Question 25

The unhappy triad

Answer 25

when knee is hit while foot is planted | --> tears multiple ligaments and menesci

Question 26

Temporomandibular Joint

Answer 26

TMJ - divided by articular disc (meniscus) into superior and inferior compartments - superior: gliding - inferior: hinge - saggital section through joint --> movement back and forth (opening/closing mouth) - lateral excursion (side to side)

Question 27

The Glenohumeral Joint

Answer 27

- ball and socket - highly mobile = not stable - glenoid cavity is not deep - dislocates easily

Question 28

The Hip Joint

Answer 28

- ball and socket - less mobility = more stable - deep acetabulum for herd of femur - ligamentum teres extend from acetabulum --> fovea captius (on head of femur) which may add stability

Question 29

The Elbow Joint

Answer 29

- hinge joint (humerus/ulna) | - -> annular ligament forms pivot at proximal radioulnar join

Question 30

Rheumatoid Arthritis

Answer 30

autoimmune disease - symptoms: pain, stiffness, weakness - begins with inflammation of synovial membrane (joint swells) - chronic inflammation of joint capsule deteriorates CT around joint

Question 31

Arthritis in Knee

Answer 31

- most common is osteoarthritis --> affects articular cartilages - "wear and tear" = stiffening, pain, swelling - extreme solution is complete replacement of knee

Question 32

hinge

Answer 32

allows flexion/extension (ex. elbow)

Question 33

pivot

Answer 33

allows rotation (ex. proximal radioulnar)

Question 34

ball and socket

Answer 34

very flexible, allows flexion/extension, adduction/abduction, and rotation (ex. hip)

Question 35

gliding

Answer 35

Two opposing articular surfaces slide past each other in almost any direction; the amount of movement is slight (ex. wrist)

Question 36

abduction

Answer 36

movement of bone away from midline

Question 37

protraction

Answer 37

Anterior movement of a body part from anatomic position

Question 38

retraction

Answer 38

Posterior movement of a body part from anatomic position

Question 39

adduction

Answer 39

movement of bone towards midline

Question 40

oppostion

Answer 40

moving dumb to touch tips of other fingers