Chapter 8: Articulations and Movement

Articulations/Joints are named by (3 things)

1. Bones/parts united (temporomandibular)
2. Only one bone (humeral)
3. Latin equivalent of common name (cubital)

Classification of joints:

1. Structural: based on major connective tissue that binds
2. Functional: based on degree of motion

3 structural joints

1. Fibrous
2. Cartilaginous
3. Synovial

3 functional joints

1. Synarthrosis (unmovable)
2. Amphiarthrosis (slightly moveable)
3. Diarthrosis (freely moveable)

Characteristics of fibrous joints (3 things)

1. united by fibrous connective tissue
2. no joint cavity
3. move little or none

3 types of fibrous joints

1. Sutures
2. Syndesmoses
3. Gomphoses

Characteristics of sutures (2 things)

1. Bones interdigitate
2. Continuous periosteum

3 types of sutures

1. Sutural ligament: two periosteum + connective tissue
2. Synostosis: fully ossified suture
3. Fontanels: in suture between bones that allow change in shape of head

Craniosynostosis

the premature fusing of the sagittal suture

2 characteristics of syndesmoses

1. Bones farther apart than a suture, and joined by ligaments
2. Some movement (radioulnar or interosseous membrane)

3 characteristics of gomphoses

1. Specialized
2. Pegs fit into sockets
3. Periodontal ligaments (hold teeth in place)

Gingivitis

inflammation of the periodontal ligaments

4 Stages of Periodontal Disease

1. Healthy teeth and gums - 0mm pockets
2. Gingivitis - 2-3mm pockets
3. Gum recession & moderate periodontitis - 4-5mm pockets
4. Advanced periodontal disease & bone loss - 6-10mm pockets

What is a fibrous joint?
A. When two bones are united by fibrous connective tissue.
B. Two bones grow together across a joint and form a single bone.
C. When two bones are united by fibrocartilage.
D. Two bones grow together across a joint and form a synovial bone.

A. When two bones are united by fibrous connective tissue.

What is synostosis?
A. When two bones are united by fibrous C. T. (connective tissue).
B. Two bones grow together across a joint and form a single bone.
C. When two bones are united by fibrocartilage.
D. Two bones grow together across a joint and form a synovial bone.

B. Two bones grow together across a joint and form a single bone.

What are the characteristics of a fibrous joint? Name three types and give an example of each.

Characteristics:
- united by a fibrous connective tissue
- no joint cavity
- don't move or move very little
Types - Example:
1. Sutures - a synostosis, like the coronal suture in your skull
2. Syndesmoses - the radioulnar membrane
3. Gomphoses - periodontal ligaments that keep teeth in place

2 types of cartilaginous joints

1. Synchondroses (hyaline cartilage)
2. Symphyses (fibrocartilage)

4 characteristics of synchondroses

1. Made of hyaline cartilage
2. Little or no movement
3. Most temporary (they turn into synostoses - ex: epiphyseal plate -> epiphyseal line)
4. Some permanent (1st costochondral joint)

2 characteristics of symphyses

1. Made of fibrocartilage
2. Slightly movable (ex: symphysis pubis, manubriosternal symphysis, intervertebral disks)

What changes in the symphysis occur during pregnancy?

Estrogen, progesterone, and relaxin cause the symphysis to become more stretchable. The joint can relax some, then after delivery it goes back to original condition.

Define cartilaginous joints, describe two different types and give an example of each.

Cartilaginous joints are joints held by hyaline or fibrocartilage. Synchondroses are made of hyaline, don't move, and usually turn into synostoses, while symphyses are made of fibrocartilage and are slightly movable. An example of a synchondrosis is the epiphyseal plate. An example of a symphysis is the manubriosternal joint.

6 characteristics of synovial joints

1. Contains synovial fluid in joint cavity
2. Allows for considerable movement
3. Make up most joints of appendicular skeleton (to provide greater mobility)
4. Complex
5. Contain hyaline cartilage
6. No blood vessels or nerves in articular cartilage, the nerves are in the capsule

Joint cavity (of synovial joint)

encloses articular surfaces with synovial fluid

Joint capsule (of synovial joint)

fibrous capsule that is continuous with the bone periosteum and is lined on the inside with the synovial membrane

What does having the nerves in the joint capsule allow for?

proprioception

Would it be okay to have nerves or blood vessels grow in the articular cartilage?

No, because it would be between two bones and the blood flow/electrical signals would be obstructed. Plus, the nerves would be pinched and would cause pain.

Synovial fluid

thin, lubricating film that covers the surfaces of joints

What would happen if the synovial membrane covered the articular cartilage?

Bursae

pockets of synovial membrane that contains synovial fluid and provides a cushion between structures

Bursitis

inflammation of a bursa

Articular disks

additional fibrocartilage that provides extra strength and support to articulation surfaces (like the TMJ, sternoclavicular and acromioclavicular joints)

Meniscus

a fibrocartilaginous pad (i.e. knee)

Tendon sheaths

synovial tissue forming bursae that surround tendons for some distance

Synovial joint characteristics include all the following except?
A. Synovial fluid.
B. Considerable movement.
C. Most joints of appendicular skeleton.
D. No joint capsule.

D. No joint capsule.

Labelled synovial joint

Housemaid's Knee

prepatellar bursitis - the prepatellar bursa (closer to the surface than the patella bone) becomes inflamed

Which of these is not associated with synovial joints?
A. Nerves in the capsule around the joint.
B. Synovial membrane lining the capsule.
C. Synovial fluid contained within the capsule.
D. Nerves on the surface of articular cartilage.

D. Nerves on the surface of articular cartilage.

Uniaxial

a joint with one axis

Biaxial

a joint with two axes at right angles to each other

Multiaxial

a joint with several axes

Plane (gliding) joints

uniaxial, where some rotation is possible but limited (Ex: intervertebral)

Saddle joints

biaxial (Ex: thumb - carpometacarpal pollicis)

Hinge joint

uniaxial, with a convex cylinder in one bone and a concavity in the other (Ex: elbow, knee, ankle, interphalangeal)

Pivot joints

uniaxial, usually with a cylindrical bony process rotating around a single axis within a circle of bone and ligament (Ex: atlantoaxial, proximal radioulnar)

Ball-and-socket joints

multiaxial (Ex: shoulder and hip joints)

Ellipsoid (Condyloid) joints

biaxial, modified ball-and-socket joints with articular surfaces like an ellipse (Ex: atlantooccipital)

Which of these Joints is correctly matched with the type of joint?
A. Atlas to occipital condyle - pivot
B. Scapula to humerus - saddle
C. Femur to coxal bone - ellipsoid
D. Tibia to talus - hinge

D. Tibia to talus - hinge

An example of a pivot joint is:
A. Atlantoaxial
B. Femerocoxal
C. Cubital

A. Atlantoaxial

3 types of movement

1. Gliding: in plane joints; slight movement
2. Angular
3. Circular

Flexion

- angular movement
- moves anterior to the coronal plane

Extension

- angular movement
- moves posterior to the coronal plane

Hyperextension

- angular movement
- extension beyond anatomical position

Plantar flexion

- angular movement
- move foot toward plantar surface (standing on tip toes)

Dorsiflexion

- angular movement
- foot lifted toward shin

Abduction

- angular movement
- take away from the midline (abducting means taking something away)

Adduction

- angular movement
- bring toward the midline ("add" something back)

Rotation

- circular movement
- turning of a structure on its long axis (medial - toward the midline, and lateral - away from the midline)
- Ex: rotation of the head, humerus, or body

Pronation

- circular movement
- palm faces posteriorly

Supination

- circular movement
- palm faces anteriorly (like you're holding soup)

Circumduction

- circular movement
- includes: flexion, extension, abduction, and adduction

Spreading the fingers apart is___.
A. Rotation
B. Flexion
C. Abduction
D. Adduction

C. Abduction

For a ballet dancer to stand on her toes, her feet must
A. Abduct
B. Plantar flex
C. Dorsiflex
D. Invert

B. Plantar flex

Nursemaid's Elbow

Subluxation of the radial head

Fix to nursemaid's elbow

supinate the wrist and flex the elbow to 90 degrees

5 types of special movements

1. elevation and depression
2. protraction and retraction
3. excursion
4. opposition and reposition
5. inversion and eversion

Elevation/Depression

scapula and mandible moves

Protraction

mandible moves anterior

Retraction

mandible moves back into the correct anatomical position

Excursion

lateral - mandible moves either to the right or left of midline (the teeth grinding motion) and medial - mandible moves back into anatomical position

Opposition

movement of thumb and little finger towards each other

Reposition

the fingers return to anatomical position

Inversion

foot moves so sole faces the opposite foot

Eversion

foot moves so sole faces laterally

Active mobility

muscle contraction results in motion

Passive mobility

outside force results in motion

What 5 things influence range of motion/amount of mobility? (the S.S. FLU)

1. Shape of articular surfaces/cartilage
2. Strength/location of ligaments and tendons
3. Location of muscles associated with joint
4. Fluid or pain in and around joint
5. Use/disuse of joint

What terms are used for turning the foot medially?
A. reversion
B. conversion
C. eversion
D. inversion

D. inversion

Define range of motion (ROM) and contrast active and passive.

ROM = amount of mobility. Active - by muscle contraction. Passive - outside force moves joint.

Touching the thumb with the little finger is called:
A. abduction.
B. adduction.
C. flexion.
D. opposition.
E. reposition.

D. opposition.

Shoulder (Glenohumeral) Joint

It's a ball-and-socket joint that is less stable (but more mobile) than the hip and can do circumduction.

Glenoid labrum

a rim of fibrocartilage around the glenoid cavity (a part of the glenohumeral joint)

What bursae are associated with the glenohumeral joint?

subacromial and subscapular bursae

Rotator cuff

four muscles that contribute to the stability of the glenohumeral joint

Where does the tendon of the biceps brachii insert?

through the glenohumeral joint capsule

Knee Joint

traditionally considered a modified hinge joint but is actually a complex ellipsoid joint

Parts of the knee joint (3)

1. Menisci
2. Cruciate ligaments (anterior and posterior)
3. Collateral ligaments

Menisci of the knee joint

fibrocartilage articular disks that build up margins of the tibia and deepen articular surface

Cruciate ligaments of the knee joint

ligaments that cross each other, forming an X between the notch in the femoral condyles (they also connect to the femur)

Anterior cruciate ligament (ACL)

prevents anterior displacement of tibia

Posterior cruciate ligament (PCL)

Prevents posterior displacement of tibia

Collateral ligaments

help strengthen knee joint

Knee injuries and disorders (4 things)

1. Football injuries: torn tibial collateral ligament, ACL, and medial meniscus
2. Bursitis
3. Chondromalacia: cartilage of patella is soft
4. Hemarthrosis: blood in joint

The fibrocartilage articular disks in this joint are referred to as menisci.
A. ankle
B. hip
C. knee
D. shoulder
E. temporomandibular

C. knee

7 effects of aging on joints

1. Tissue repair slows
2. Rate of new blood vessel development decreases
3. Articular cartilages wear down
4. Matrix becomes more rigid
5. Production of synovial fluid declines
6. Ligaments and tendons become shorter + decreased activity, both resulting in less flexibility and a decrease in range of motion (ROM)
7. Muscles around joints weaken

Joint disorders (3 things)

1. Arthritis
2. Osteoarthritis
3. Rheumatoid arthritis

Arthritis

inflammation of any joint (14% of people have it, there are more than 100 types, and swimming/walking is best for sufferers of it)

Osteoarthritis (OA)

wear and tear inflammation (most common, 10% of people in the USA have it)

Rheumatoid arthritis (RA)

autoimmune disease that causes inflammation in the joints (the ratio of women to men who have it is 3:1, can cause ulnar drift)