Structural Classification

Question 1

Structural classifications are based on whether…

Answer 1

fibrous tissue, cartilage, or a joint cavity separates the bony regions at the joint

Question 2

In fibrous joints, the bones are united by…

Answer 2

fibrous tissue

Question 3

The sutures of the skull are examples of what joint?

Answer 3

fibrous joint – in sutures, the irregular edges of the bones interlock and are bound tightly together by connective tissue fibers.

Question 4

Syndesmoses are examples of what joint?

Answer 4

fibrous joint

Question 5

In comparison to sutures, the connecting fibers in syndesmoses are

Answer 5

longer, so the joint has more “give”

Question 6

The joint connecting the distal ends of the tibia and fibula is a

Answer 6

syndesmosis

Question 7

In cartilaginous joints, the bone ends are connected by

Answer 7

fibrocartilage

Question 8

The pubic symphysis of the pelvis is specifically what kind of joint?

Answer 8

symphysis, or an amphiarthrotic cartilaginous joint

Question 9

Intervertebral joints of the spinal columns are specifically what kind of joints?

Answer 9

symphyses (amphiarthrotic cartilaginous joints,) where the bone surfaces are connected by discs of fibrocartilage

Question 10

The hyaline-cartilage epiphyseal plates of growing long bones are what kind of joints?

Answer 10

synchondroses (synarthrotic cartilaginous joints)

Question 11

The joints between the first ribs and the sternum are what kind of joints?

Answer 11

synchondroses (synarthrotic cartilaginous joints)

Question 12

Joints in which the articulating bone ends are separated by a joint cavity are called ____ and contain ____

Answer 12

synovial joints; synovial fluid

Question 13

All synovial joints have these four distinguishing features:

Answer 13

1. Articular (hyaline) cartilage covers the ends
2. Articular capsule encloses joint surfaces; it is lined with a smooth synovial membrane
3. Articular capsule encloses a joint cavity, which contains lubricating synovial fluid
4. Fibrous layer of the articular capsule is usually reinforced with ligaments

Question 14

Not strictly part of synovial joints, but are often found closely associated with them

Answer 14

Bursae and tendon sheaths

Question 15

Bursae and tendon sheaths are essentially

Answer 15

bags of lubricant, acting like ball bearings to reduce friction between adjacent structures during joint activity

Question 16

What are bursae defined to be?

Answer 16

flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid; common where tissues rub together

Question 17

What are tendon sheaths defined to be?

Answer 17

Essentially elongated bursae that wrap completely around tendons subjected to friction (like a bun around a hot dog)

Question 18

When a dislocation happens, bone is

Answer 18

forced out of its normal position in the joint cavity

Question 19

The process of returning bone to its proper position is called

Answer 19

reduction, which should only be done by a physician

Question 20

The shapes of articulating bone surfaces determine what?

Answer 20

what movements are allowed at a joint

Question 21

Sutures are amphiarthrotic as

Answer 21

fontanels (colloquially “soft spots” on the infant skull)

Question 22

Sutures can become …

Answer 22

synostoses, or fused together as bony joints (osseous union)

Question 23

Define interosseous membrane.

Answer 23

broad and thin plane of fibrous tissue; commonly found in syndesmoses

Question 24

What are ligaments?

Answer 24

bands of dense regular connective, or fibrous, tissue bundles that connect bones to bones to form joints

Question 25

Gomphosis is the only joint between

Answer 25

teeth and bone (a.k.a dentoalveolar joint)

Question 26

Describe gomphosis

Answer 26

synarthrotic joint; cone-shaped peg in socket

Question 27

Synovial joints are connected by

Answer 27

dense irregular connective tissue

Question 28

What are the two layers of the articular capsule

Answer 28

the fibrous capsule and synovial membrane

Question 29

The fibrous capsule is made of what tissue and attaches where?

Answer 29

It is dense regular connective tissue that attaches to the periosteum or ligaments

Question 30

The synovial membrane is made of what tissue and does what?

Answer 30

It is loose areolar connective tissue and produces synovial fluid.

Question 31

What are the functions of synovial fluid?

Answer 31

Shock absorption, nutrients, removes microbes & debris, reduces friction

Question 32

Reinforcing (accessory) ligaments are found at

Answer 32

larger joints, or joints under much stress that need more stablization/support e.g. the cruciate ligaments (anterior, medial and posterior) at the knee

Question 33

What are articular discs?

Answer 33

Also known as menisci; cartilage that helps maintain stability and fit different shapes together at joint (e.g. temporomandibular joint, knee)

Question 34

Name the 6 classifications of synovial joints based on shape.

Answer 34

Plane, hinge, pivot, condylar, saddle, and ball-and-socket joints

Question 35

Describe a plane joint.

Answer 35

articular surfaces are essentially flat; only short slipping/gliding movements allowed; movements are nonaxial (no rotation around any axis)

Question 36

The intercarpal and intertarsal joints are the best examples of

Answer 36

plane joints, gliding movement

Question 37

What are the four main categories of movement for synovial joints?

Answer 37

Gliding, angular, rotational, and special

Question 38

Angular movements that involve angular change include:

Answer 38

flexion & extension; lateral flexion & lateral extension; hyperextension; abduction & adduction; circumduction

Question 39

Describe a hinge joint

Answer 39

cylindral end of one bone fits into a trough-shaped surface of another (convex fits into concave); uniaxial, movement allowed in just one plane

Question 40

The elbow joint, ankle joint and the joints between the phalanges of the fingers are classified as

Answer 40

hinge joints

Question 41

Head shaking no and foot moving laterally and medially are examples of what kind of movement

Answer 41

rotational

Question 42

What are the special movements?

Answer 42

Elevation & depression; protraction & retraction; inversion & eversion; dorsiflexion & plantar flexion; supination & pronation; opposition

Question 43

Describe a pivot joint

Answer 43

rounded end of one bone fits into a sleeve/ring of bone (and possibly ligaments); uniaxial, rotating bone can only turn around its long axis

Question 44

The proximal radioulnar joint and the joint between the atlas and dens are classified as

Answer 44

pivot joints

Question 45

Describe a condylar joint (ellipsoid)

Answer 45

egg-shaped articular surface of one bone fits into an oval concavity in another; biaxial, allows side to side and back and forth movement but no rotating around its long axis

Question 46

Knuckle (metacarpophalangeal) joints are classified as

Answer 46

condylar joints

Question 47

Describe a saddle joint

Answer 47

each articular surface has both concave and convex areas (like a saddle); biaxial, allows essentially the same movements as condylar joints

Question 48

Carpometacarpal joints in the thumb are the best examples of

Answer 48

saddle joints

Question 49

Describe a ball-and-socket joint

Answer 49

spherical head of one bone fits into a round socket in another; multiaxial, allows movement in all axes (including rotation); most freely moving synovial joints

Question 50

The shoulder and hip are examples of

Answer 50

ball-and-socket joints

Question 51

Factors affecting range of motion of synovial joints:

Answer 51

structure/shape of articulating bones; strength/tension of ligaments; arrangement & tension of muscles; contact of soft parts (e.g. adipose); hormones; disuse