Articulations and Body Movements

Question 1

Articulations

Answer 1

Joints that hold bones together and allow the rigid skeletal system some flexibility so that gross body movements can occur

Question 2

Structural classifications of joints

Answer 2

Fibrous, cartilaginous and synovial joints

Question 3

Functional classifications of joints

Answer 3

Synarthroses, amphiarthroses, diarthroses

Question 4

Synarthroses

Answer 4

Immovable joints

Question 5

Amphiarthroses

Answer 5

Slightly movable joints

Question 6

Diarthroses

Answer 6

Freely movable joints

Question 7

Where do diarthroses joints predominate?

Answer 7

In the limbs

Question 8

Where do synarthroses and amphiarthroses joints predominate?

Answer 8

Restricted to the axial skeleton, where firm bony attachments and protection of enclosed organs are priorities

Question 9

General rule about fibrous and synovial joints

Answer 9

Fibrous joints are immovable and synovial joints are feely movable

Question 10

General rule about cartilaginous joints

Answer 10

Offers both rigid and slightly movable examples

Question 11

Fibrous joints

Answer 11

Bones joined by fibrous tissue, no joint cavity is present. Amount of movement depends on length of fibers uniting bones. Some are slightly movable, most are synarthrotic and permit virtually no movement.

Question 12

2 major types of fibrous joints

Answer 12

Sutures and syndesmoses

Question 13

Sutures

Answer 13

Irregular edges of the bones interlock and are united by very short connective tissue fibers

Question 14

Syndesmoses

Answer 14

Articulating bones are connected by short ligaments of dense fibrous tissue; bones do not interlock.

Question 15

Cartilaginous joints

Answer 15

The articulating bone ends are connected by a plate or pad of cartilage. No joint cavity is present. Most are slightly movable (amphiarthrotic)

Question 16

2 major types of cartilaginous joints

Answer 16

Synchondroses and symphyses

Question 17

Symphyses

Answer 17

Bones are connected by a broad, flat disc of fibrocartilage. i.e. intervertebral joints and pubic symphysis

Question 18

Synchondroses

Answer 18

Bony portions are united by hyaline cartilage. i.e. articulation of costal cartilage of the ribs to the sternum

Question 19

Synovial joints

Answer 19

Articulating bone ends are separated by a joint cavity containing synovial fluid. All are diarthroses (freely movable)

Question 20

Movement of Synovial joints

Answer 20

All are freely movable joints (diarthroses) but mobility varies: some synovial joints permit only small gliding movements, and others can move in several planes.

Question 21

Structural characteristics of synovial joints

Answer 21

1. Enclosed by a 2-layered articular capsule, creating a joint cavity.
2. Inner layer is smooth CT membrane (synovial membrane) producing lubricating fluid to reduce friction. Outer layer dense irregular CT
3. Articular (hyaline) cartilage covers surfaces of the bones forming a joint
4. Articular capsule typically reinforced with ligaments and may contain bursae
5. Fibrocartilage pads (articular discs) may be present within capsule

Question 22

What determines the types of movements that can occur at the joint and the structural classification of the joints?

Answer 22

The shapes of the articular surfaces

Question 23

Plane (Nonaxial) joint

Answer 23

Articulating surfaces are flat or slightly curved. Allow only gliding movements as the surfaces slide past one another.

Question 24

Example of Plane (nonaxial) joint

Answer 24

Intercarpal joints, intertarsal joints, and joints between vertebral articular surfaces

Question 25

Hinge (Uniaxial) joint

Answer 25

The rounded or cylindrical process of one bone fits into the concave surface of another bone, allowing movement in one plane, usually flexion and extension.

Question 26

Example of Hinge (uniaxial) joint

Answer 26

Elbow and interphalangeal joints

Question 27

Pivot (Uniaxial) joint

Answer 27

The rounded surface of one bone articulates with a shallow depression or foramen in another bone, permitting rotational movement in one plane.

Question 28

Example of Pivot (uniaxial) joint

Answer 28

Proximal radioulnar joint and atlantoaxial joint (between C1 and C2).

Question 29

Condylar (Biaxial) joint

Answer 29

The oval condyle of one bone fits into an ellipsoidal depression in another bone to allow movement in two planes, usually flexion/extension and abduction/adduction.

Question 30

Example of Condylar (biaxial) joint

Answer 30

Wrist and metacarpophalangeal (knuckle) joints

Question 31

Saddle (Biaxial) joint

Answer 31

Articulating surfaes are saddle shaped; one surface is convex, and the other is concave. Permits movement in two planes, flexion/extension and abduction/adduction

Question 32

Example of Saddle (biaxial) joint

Answer 32

Carpometacarpal joints of the thumb

Question 33

Ball-and-socket (multiaxial) joint

Answer 33

Ball-shaped head of one bone fits into a cup like depression of another bone. Permits flexion/extension, abduction/adduction, and rotation, which combine and allow movement in many planes.

Question 34

Example of Ball-and-socket (multiaxial) joint

Answer 34

Shoulder and hip

Question 35

Origin

Answer 35

The stationary, immovable, or less movable attachment

Question 36

Insertion

Answer 36

The movable attachment

Question 37

How does body movement occur?

Answer 37

When muscles contract across diarthrotic synovial joints and the insertion moves towards the origin

Question 38

What does the type of movement depend on?

Answer 38

The construction of the joint and on the placement of the muscle relative to the joint

Question 39

Flexion

Answer 39

Movement generally in sagittal plane, that decreases the angle of the joint and reduces the distance between the two bones.

Question 40

What joints are typical of flexion?

Answer 40

Hinge joints (bending knee or elbow) but also common at ball-and-socket joints (bending forward at the hip)

Question 41

Extension

Answer 41

Movement increases the angle of a joint and the distance between two bones or parts of the body (straightening the knee or elbow); opposite of flexion.

Question 42

Hyperextension

Answer 42

if extension proceeds beyond anatomical position (bends trunk backward)

Question 43

Abduction

Answer 43

Movement of limb away from midline or median plane of body, generally on the frontal plane, or the fanning movement of fingers or toes when they are spread apart

Question 44

Adduction

Answer 44

Movement of limb toward the midline of the body or drawing the fingers or toes together. Opposite of abduction

Question 45

Rotation

Answer 45

Movement of a bone around its longitudinal axis without lateral or medial displacement.

Question 46

What joints are typical of rotation?

Answer 46

Ball-and-Socket joints and the movement of the atlas around the dens of the axis

Question 47

Circumduction

Answer 47

A combination of flexion, extension, abduction, and adduction commonly observed in ball-and-socket joints like the shoulder. Proximal end of the lib remains stationary, and the distal end moves in a circle.

Question 48

What joints are typical of circumduction?

Answer 48

Ball-and-socket mainly but condylar and saddle joints also allow circumduction

Question 49

Pronation

Answer 49

Movement of the palm of the hand from an anterior or upward-facing position to a posterior or downward-facing position. Distal end of radius moves across the ulna forming an X

Question 50

Supination

Answer 50

Movement of the palm from a posterior position to an anterior position (anatomical position); opposite of pronation. Radius and ulna are parallel.

Question 51

Dorsiflexion

Answer 51

Movement of the ankle joint that lifts the foot so that its superior surface approaches the shin

Question 52

Pantar flexion

Answer 52

Movement of the ankle joint in which the foot is flexed downward as if standing on one's toes or pointing the toes

Question 53

Inversion

Answer 53

Movement that turns the sole of the foot medially

Question 54

Eversion

Answer 54

Movement that turns the sole of the foot laterally; opposite of inversion