Chapter 9 Joints

Question 1

describe articulations

Answer 1

body movement occurs at joints, known as articulation, where two bones connect

Question 2

the significance of joint structure

Answer 2

determines direction and distance of movement

Question 3

inverse relationship between joint strength and joint mobility

Answer 3

joint strength decreases as mobility increases

Question 4

list the 2 methods of joint classification

Answer 4

functional and structural classification

Question 5

functional classification

Answer 5

based on range of motion of the joint

Question 6

structural classification

Answer 6

relies on the anatomical organization of the joint

Question 7

define synarthrosis

Answer 7

an immovable joint. can be fibrous or cartilaginous, depending on the type of connection formed by the two bones in the joint. over time, these two bones may fuse/ossify, forming a bony joint.

Question 8

examples of synarthrosis

Answer 8

sutures, gomophosis, synchronous, and synostoses

Question 9

suture

Answer 9

a synarthrotic joint located only between the bones of the skull. the edges of the bones are interlocked and bound together at the suture by dense fibrous conn. tissue.

Question 10

gomphosis

Answer 10

a synarthrosis that binds the teeth to bony sockets in the maxillae and mandible. the fibrous connection between a tooth and its socket is a periodontal ligament.

Question 11

synchondrosis

Answer 11

a rigid, cartilaginous bridge between two articulating bones.

Question 12

examples of synchondroses

Answer 12

the cartilaginous connection between the ends of the first pair of vertebrosternal ribs and manubrium of the sternum, and epiphyseal cartilage, which connects the diaphysis to the epiphysis in growing long bone

Question 13

Hyperextension

Answer 13

When the extension is past the anatomical position (greater than 180 degrees).

Question 14

What kind of movements are abduction and adduction?

Answer 14

Movements of the appendicular skeleton.

Question 15

Abduction

Answer 15

Moving a limb away from the midline. Frontal plane. Eg. = raising arm laterally, spreading fingers apart.

Question 16

Adduction

Answer 16

Opposite of abduction. Movement of a limb towards the midline. Frontal plane.

Question 17

Rotation

Answer 17

Circular movement of bone around its axis. Two types, medial (inward) and lateral (outward). E.g. = movement between c1 and c2, “no” head shaking movement.

Question 18

Medial (Inward) Rotation

Answer 18

Rotates toward axis.

Question 19

Lateral (Outward) Rotation

Answer 19

Rotates away from axis.

Question 20

Circumduction

Answer 20

Combo of flexion, extension, abduction, and adduction. Proximal end of limb is stationary, distal end moves in a circle. Circular or cone-shaped movement, no rotation. E.g. = ball-and-socket joint of shoulder, rotating hand from wrist.

Question 21

Synostosis

Answer 21

A totally rigid, immovable joint created when two bones fuse and the boundary between them disappears.

Question 22

Examples of Synostoses

Answer 22

Frontal (metopic) suture of the frontal bone and the fusion of an infant’s left and right mandibular bones.

Question 23

Define an amphiarthrosis.

Answer 23

A slightly movable joint. Either fibrous or cartilaginous, depending on the type of connection between the opposing bones.

Question 24

Examples of Amphiarthroses

Answer 24

Syndesmoses and symphyses.

Question 25

Syndesmosis

Answer 25

At a syndesmosis, bones are connected by a ligament. One example is the distal joint between the tibia and the fibula.

Question 26

Symphysis

Answer 26

Articulating bones are connected by a wedge or pad of fibrocartilage. The joint between the two pubic bones, the pubic symphysis, is an example.

Question 27

Define a diarthrosis.

Answer 27

A freely movable joint, AKA synovial joint. Diarthroses are subdivided functionally, according to their planes of movement.

Question 28

Briefly describe a diarthrosis/synovial joint.

Answer 28

At the ends of long bones, within articular capsules, lined with synovial membranes.