Chapter 9: Articulations

Question 1

Articulations (joints)

Answer 1

Sites where two or more bones meet.

Question 2

What are the functions of articulations?

Answer 2

Hold bones together and allows for mobility

Question 3

How are joints classified?

Answer 3

Structurally and functionally

Question 4

How are joints classified structurally?

Answer 4

Fibrous- dense connective tissue
Cartilaginous- Some type of cartilage
Synovial- fluid-filled cavity surrounded by a capsule.

Question 5

What are the three different ways joints are classified functionally?

Answer 5

Synarthroses
Amphiarthroses
Diarthroses

Question 6

Synarthroses

Answer 6

Without movement
These joints are either fibrous or cartilaginous

Question 7

Amphiarthroses

Answer 7

Slight movement
Either fibrous or cartilaginous

Question 8

Diarthroses

Answer 8

Freely moveable
Synovial joints

Question 9

Fibrous Structural Joints

Answer 9

Synarthrotic
Extremely strong joints located where movement between the bones must be prevented.

Question 10

What are some types of fibrous structural joints?

Answer 10

Sutures- between the bones of the skull. Allow for growth. Becomes synostoses (bony junction)
Syndesmoses (ligaments) between bones, like the distal connection between the tibia and fibular and interosseous membrane.
Gomphoses- peg-in-socket, periodontal ligament around the tooth.

Question 11

Cartilaginous Joints

Answer 11

Made of hyaline cartilage
Synarthrotic or Amphiartrotic

Question 12

What are some types of cartilaginous joints?

Answer 12

Synchondrosis -hyaline cartilage in the epiphyseal plates and between the first rib and the manubrium of the sternum. (synarthrotic)
Symphyses - hyaline cartilage fused to an intervening pad of fibrocartilage. Shock absorber. Designed for strength and flexibility. (Amphiarthrotic) in intervertebral joints and pubic symphysis.

Question 13

Synovial Joints

Answer 13

Articulating bones are separated by a fluid-containing joint cavity.
Freely moveable
All limb joints are synovial joints.

Question 14

What is the general structures of synovial joints

Answer 14

Articular cartilage- covers articulating surfaces.
Articular Capsule- two layered capsules surround the joint.
Synovial fluid - lubrication, nutrient distribution, and shock absorption.
Reinforcing Ligaments and Tendons- localized thickening that supports, strengthen, and reinforce synovial joints (ligaments) and stabilize the joint (tendons)

Question 15

What are the friction-reducing structures associated with synovial joints?

Answer 15

Bursae- small, thin, fluid-filled pockets in connective tissue that reduce friction and act as shock absorbers that contain synovial fluid.
Tendon sheaths- Tubular bursae surround tendons where they cross bony surfaces.

Question 16

Gliding

Answer 16

Two opposing surfaces glide past each other.

Question 17

Angular

Answer 17

Increase or decrease the angle between two bones.

Flexion, extension, hyperextension, abduction, and circumduction and rotation.

Question 18

Rotational

Answer 18

Turning around the longitudinal axis of the body or the limb.

Such as rotating your head around or rotating your leg.

Question 19

What are the types of shapes or synovial joints?

Answer 19

Plane
Hinge
Pivot
Condyloid
Saddle
Ball-and-socket

Question 20

Plane Joint

Answer 20

Articular flattened face surfaces slide across one another.
Only very slight movement.
Gliding
Nonaxial
Examples: end of clavicles and between carpal and tarsals.

Question 21

Hinge Joint

Answer 21

Cylindrical projections of one bone fit into a through-shaped surface on another.
Permits angular motion.
Uniaxial
Examples: elbow, knee, ankle, and interphalangeal joints.

Question 22

Pivot Joints

Answer 22

Rounded end of one bone protrudes into a “sleeve’ or ring composed of the bone of another.
Permits only rotation
Uniaxial
Example: joint between the axis and the atlas, and the proximal radioulnar joint.

Question 23

Condyloid Joint

Answer 23

Oval articular surface of a bone fits into a complementary depression in another.
Angular motion occurs in two planes.
Biaxial
Examples: radiocarpal joints and metacarpophalangeal joints.

Question 24

Saddle Joint

Answer 24

Articular faces that resemble saddles. Each face is concave on one side and convex on the other.
Opposing faces nest together.
Permits angular motion, including circumduction but prevents rotation.
Biaxial
Examples: carpometacarpal joint at the base of the thumb.

Question 25

Ball-and-socket Joint

Answer 25

The round head of one bone nests in a cup-like depression.
Multiaxial
Examples: shoulder and hip joint.

Question 26

What kind of joints are knee and elbow?

Answer 26

Hinge joints

Question 27

What are the three joints in the knee?

Answer 27

Femoropatellar joint
Medial and lateral tibiofemoral joints.

Question 28

What are the tendons and ligaments of the knee joints?

Answer 28

Tendon of the quadriceps femoris muscle
Lateral and medial patellar retinacula.
Patellar Ligament
Fibular and tibial collateral ligaments.

Question 29

Anterior Cruciate Ligament (ACL)

Answer 29

Prevents forward displacement of the tibia.

Question 30

Posterior Cruciate Ligament

Answer 30

Prevents backward displacement of the tibia.

Question 31

Menisci

Answer 31

Semilunar cartilages prevent side-to-side rocking of the femur on tibia.
Medial and Lateral Menisci

Question 32

What are the two common injuries to the knee?

Answer 32

Lateral blows to extended knee- tear tibial collateral ligament, medial meniscus and ACL.
Torn Anterior Cruciate Ligament-
Heal poorly, occurs when there is a sudden change in direction while running.

Question 33

What are the ligaments of the elbow?

Answer 33

Ulnar and radial collateral ligaments - prevent side-to-side movement.
Annular ligament- surrounds the head of the radius. Supination and pronation.

Question 34

Temporomandibular Joint

Answer 34

Modified hinge joint.
Mandibular condyle articulates with the mandibular fossa on the temporal bone.

Question 35

What types of movement does the temporomandibular joint make?

Answer 35

Gliding, hinge, and side to side.

Question 36

What are the two important parts of the temporomandibular joint?

Answer 36

Articular Disc- made of fibrocartilage, divides the joint into two compartments. Superior (Protraction and retraction) and Inferior (depression and elevations) Lateral ligament- strengthen TMJ laterally. Prevent posterior dislocation.

Question 36

Translation of the temporomandibular joint

Answer 36

Allows one to open the mouth wider to spread the upper and lower teeth
The head of the mandible and articular disc move forward until the head lies under the articular tubercle.

Question 37

Dislocation of the temporomandibular joint

Answer 37

Heads of the mandible can dislocate anteriorly out of alignment with the mandibular fossa.
Jaw “locked” open
Posterior dislocation is prevented by lateral ligament.

Question 38

What are the five ligaments of the shoulder or glenohumeral joint?

Answer 38

Coracohumeral, glenohumeral, coracocrominal, coracoclavicular, acromioclavicular ligaments.

Question 39

Tendon of the long head of biceps

Answer 39

Travels through the intertubercular groove and secures the humerus to the glenoid cavity.

Question 40

Rotator Cuff

Answer 40

4 short muscles- supraspinatus, infraspinatus, subscapularis and teres minor.
Across and surround the joint.
Holds the large head of humerus in a smaller and shallow glenoid cavity of scapula.

Question 41

What are the ligaments in the hip joint?

Answer 41

Iliofemoral ligament (y-shaped, strongest ligament, prevent hyperextension)
Pubofemoral (orevents over-abduction of hip)
Ichiofemoral ligament (weakest ligament of the three, located posteriorly)