Chapter 8

Question 1

Define articulation

Answer 1

the meeting place of two or more bones; also called a joint

Question 2

Define articulate

Answer 2

to connect with a joint or something that is like a joint

Question 3

Describe the relationship between joint stability and joint mobility

Answer 3

there is an inverse relationship between joint stability and joint mobility; the more freely a joint can move (increased joint mobility), the less stable the joint is and the more prone to injury the joint is

Question 4

Explain the difference between the functional classification of joints and the structural classification of joints

Answer 4

functional classification - classifies joints by the amount of movement allowed
structural classification - classifies joints by the type of connective tissue connecting the bones

Question 5

Define the fibrous structural joint type and give an example

Answer 5

joints where connective tissue fibers (primarily collagen) connect bones; length of fibers + opposing shapes of articulating bones determine whether no or slight movement is allowed
Examples: suture (coronal, sagittal, lambdoid sutures), syndesmosis (interosseous membranes between radius/ulna and tibia/fibula, distal tibiofibular joint), gomphosis (dentoalveolar joints)

Question 6

Define the cartilaginous structural joint type and give an example

Answer 6

joints where bones are connected by either hyaline cartilage or fibrocartilage
Examples: synchondrosis (epiphyseal plate, 1st sternocostal joint), symphysis (intervertebral disc, pubic symphysis joints)

Question 7

Define the synovial structural joint type and give an example

Answer 7

freely movable joints (diarthroses) that are characterized by a joint cavity containing synovial fluid; the most common joints in the adult appendicular skeleton
Examples: shoulder, elbow, wrist, hip, knee

Question 8

Define the synarthrosis functional joint type and give an example

Answer 8

immovable joints that allow no movement in normal conditions
Examples: cranial suture joints (coronal, sagittal, lambdoid sutures), gomphosis joints (dentoalveolar joints), synchondrosis joints (epiphyseal plate, 1st sternocostal joint)

Question 9

Define the amphiarthrosis functional joint type and give an example

Answer 9

slightly movable joints
Examples: syndesmosis joints (interosseous membranes between radius/ulna + tibula/fibula, distal tibiofibular joint), symphysis joints (intervertebral disc, pubic symphysis joints)

Question 10

Define the diarthrosis functional joint type and give an example

Answer 10

freely movable joints
Examples: synovial joints (shoulder, elbow, wrist, hip, knee)

Question 11

Specify the locations of suture joints

Answer 11

connect the membranous bones of the skull

Question 12

Specify the locations of syndesmosis joints

Answer 12

bones are connected by an interosseous ligament; located between the distal portions of the tibia + fibula, as well as the interosseous membranes between the radius + ulna and tibia + fibula

Question 13

Specify the locations of gomphosis joints

Answer 13

joints of the teeth

Question 14

Describe the differences between synchondroses and symphyses and give examples of each type of joint

Answer 14

synchondroses - unites the bones with hyaline cartilage; also known as a primary cartilaginous joint
Example: sternum; costal (rib) cartilage
symphyses - unites the bones with a disc of fibrocartilage; also known as a secondary cartilaginous joint
Example: pubic symphysis (between two pubic bones), intervertebral disc joint (located between adjacent vertebral bodies)

Question 15

Identify ligament

Answer 15

reinforce the joint capsule; may provide support and limit movement

Question 16

Identify joint capsule

Answer 16

stabilizes the joint by limiting movement, and varies in thickness according to the stress it encounters; outer layer is made of dense fibrous connective tissue that is continuous with the periosteum of the articulating bones

Question 17

Identify synovial membrane

Answer 17

soft connective tissue lining of the joint capsule; composed of loose connective tissue that includes blood and lymphatic vessels within a collagen matrix; secretes a small amount of synovial fluid into the joint cavity

Question 18

Identify joint cavity

Answer 18

a cavity in the joint formed by enclosing the articulating bones with a joint capsule

Question 19

Identify articular cartilage

Answer 19

dense, fibrous collagen fibers that provide a cushion between articulating bones

Question 20

Identify synovial fluid

Answer 20

a fluid located in the joint cavity that functions as a biological lubricant by reducing friction in moving joints; also acts as a shock absorber, provides nutrients and oxygen to the articular cartilage, and removes waste from them

Question 21

List an example of hinge synovial joints

Answer 21

hinge - articulation between a concave surface of one bone with a convex surface of another bone; a uniaxial joint; allows flexion and extension (which occur in the antero-posterior plane)
Examples: ulnohumeral joint (joint of elbow between trochlear notch of ulna and trochlea of the humerus) and interphalangeal joints of fingers and toes

Question 21

List an example of pivot synovial joints

Answer 21

pivot - rotate about a longitudinal axis and feature an articular surface shaped like a cylinder, which rotates within a ring formed of bone and ligament; a uniaxial joint; allows pronation and supination (in the forearm), as well as rotation left and right (between C1 and C2 vertebrae)
Examples: atlanto-axial joint (between C1 and C2 cervical vertebrae), proximal radioulnar joint (head of radius and radial notch of ulna and annular ligament)

Question 22

List an example of ball and socket synovial joints

Answer 22

ball and socket - feature a spherical surface articulating with a cup-shaped socket; triaxial joint; allows three planes of movement: rotation about a longitudinal axis, flexion and extension, abduction and adduction, and circumduction (found in biaxial joints)
Examples: shoulder, hip

Question 23

List an example of plane (gliding) synovial joints

Answer 23

plane (gliding) - describes joints that have no identifiable axis of rotation, and thus categorized as “nonaxial”; instead, allow slight gliding movements in many directions
Example: joints between articular facets on vertebral arches, between most carpal and tarsal bones, and between ribs and vertebrae

Question 24

Define the abduction joint movement and give an example

Answer 24

movement away from the midline that occurs in a frontal plane
Example: moving hand upwards so arm forms a “T” shape

Question 25

Define the adduction joint movement and give an example

Answer 25

movement towards the midline that occurs in a frontal plane
Example: moving hand from higher position back to anatomical position

Question 26

Define the flexion joint movement and give an example

Answer 26

movement along the sagittal plane that decreases the joint angle between the moving segment and its proximal segment; can also be considered a forward movement (beginning from anatomical position)
Example: bending of elbow bringing hand towards shoulder

Question 27

Define the extension joint movement and give an example

Answer 27

movement along the sagittal plane that increases the joint angle between the moving segment and its proximal segment; can also be considered a backward movement (beginning from anatomical position)
Example: straightening elbow bringing hand away from shoulder

Question 28

Define the pronation joint movement and give an example

Answer 28

rotation of the radius and ulna that results in crossed bones and palm facing posterior
Example: rotation at proximal and distal radioulnar joints

Question 29

Define the supination joint movement and give an example

Answer 29

rotation of the radius and ulna that results in uncrossed bones and palm facing anterior
Example: rotation at proximal and distal radioulnar joints

Question 30

Define the rotation joint movement and give an example

Answer 30

Rotation. - movement around the longitudinal axis of the moving segment
Example: shaking head “no”, rotation of intervertebral joints of spine (“cracking your back”), rotation at ball and socket joints

Question 31

Define the supination special joint movement

Answer 31

rotation of the radius and ulna that results in uncrossed bones and palm facing anterior

Question 32

Define the pronation special joint movement

Answer 32

rotation of the radius and ulna that results in crossed bones and palm facing posterior

Question 33

Define the dorsiflexion special joint movement

Answer 33

moves dorsum of the foot from anatomical position towards the leg

Question 34

Define the plantarflexion special joint movement

Answer 34

moves the plantar surface (sole) of the foot in an inferior direction (as in standing on toes; equivalent of extension)

Question 35

Define the inversion special joint movement

Answer 35

moves the plantar surface (sole) of the foot medially

Question 36

Define the eversion special joint movement

Answer 36

moves the plantar surface (sole) of the foot laterally

Question 37

Define the opposition special joint movement

Answer 37

movement of the hand in which the thumb contacts any of the fingers (but typically the second finger); also known as the “pincer grasp”

Question 38

Define the protraction special joint movement

Answer 38

movement in the anterior direction possible at the temporomandibular (jaw) and scapulothoracic joints that occurs in the transverse plane

Question 39

Define the retraction special joint movement

Answer 39

movement in the posterior direction possible at the temporomandibular (jaw) and scapulothoracic joints that occurs in the transverse plane

Question 40

Define the elevation special joint movement

Answer 40

movement upwards (or superiorly)

Question 41

Define the depression special joint movement

Answer 41

movement downwards (or inferiorly)