Articular System

Question 1

Meaning

Answer 1

JOINT or ARTICULATION

1. Origin: ARTICULUS (Latin=joint)
2. Definition: refers to connections between components of the skeletal system

Question 2

Arthrology

Answer 2

1. Origin: ARTHRON (Greek=joint)

2. Definition: study of joints

Question 3

Arthritis

Answer 3

1. Origin: ARTHRON (Greek=joint)

2. Definition: inflammation of joints

Question 4

Fibrous (synarthroses) joints

Answer 4

intervening tissue is merely fibrous connective tissue

Question 5

Cartilaginous (amphiarthroses)

Answer 5

intervening tissue is cartilage

Question 6

Synovial (diarthroses)

Answer 6

intervening tissue is synovial fluid

Question 7

Fibrous

Suture

Answer 7

1. formed by two bones whose articulating surfaces are serrated
   a. for example, in the form of interdigitations
   b. these interdigitating borders are held together by fibrous connective
2. it is immovable
3. it is located only in the skull
4. Example: sagittal suture

Question 8

Syndesmoses

Answer 8

1. a fibrous joint in which the intervening connective tissue is of greater amount than that found in a suture
2. it is slightly moveable
3. it is located btwn the 2 bones of the forearm and the 2 bones of the leg.
4. Example: radioulnar syndesmosis (in which the intervening connective tissue is the interosseous membrane)

Question 9

Hyaline cartilage joint

Answer 9

1. a joint in which the intervening tissue is hyaline cartilage
2. it is immovable
3. located between the epiphysis and diaphysis of growing bone
   a. it is a temporary condition that will later ossify
4. Example: epiphyseal disc

Question 10

Fibrocartilaginous joint

Answer 10

1. a joint in which the intervening tissue is fibrocartilage
2. It is slightly moveable
3. Locations:
   Examples:
   i. between adjacent vertebral bodies: intervertebral discs
   ii. between the right and left pubic bones; interpubic disc

Question 11

Synovial joint

Answer 11

Joint characterized by the possession of a cavity and specialized to permit free movement
A. a joint in which the intervening tissue is synovial fluid
B. The ends of the articulating bones are covered by ARTICULAR CARTILAGE
1.it is a layer of hyaline cartilage
2. it is avascular
3. it lacks nerves
4. it is radiolucent (cannot be seen on radiographs)
C. The ARTICULAR CAPSULE encapsulates the joint
1. The articular capsule connects together the 2 bones and completely encircles the joint, thus enclosing the synovial cavity
2. It is composed of two layers
a. an outer fibrous layer that is continuous w the periosteum of bone
b. an inner layer that is called the SYNOVIAL MEMBRANE that lines the inside of the fibrous layer
i. it is quite vascular and produces the synovial fluid that fills the synovial cavity
ii. it lubricates the joint and nourishes the articular cartilage
D. The synovial fluid is derived from blood

Question 12

Gliding Movements

Answer 12

a. involve a sligh slipping of 1 bone over another, usually flat surfaces
b. little actual movement occurs

Question 13

Angular Movements

Answer 13

a. Flexion: bending of a joint so that the angle becomes more acute
b. Extension: straightening of a flexed joint
c. abduction: movement in a frontal plane away fro the median plane
d. adduction: movemnt in a frontal plane toward the median place
e. circumduction: combination of the above 4 movements
f. angular movements of the foot at the ankle joint:
i. dorsiflexion- moving the dorsum of the foot toward the anterior leg
ii. plantar flexion- moving the dorsum of the foot away from the anterior leg
iii. eversion- moving the lateral surface of the foot superiorly
iv. inversion- moving the medial surface of the foot superiorly
photos on pg 39

Question 14

Medial Rotation

Answer 14

anterior aspect of the limb rotates medially

Question 15

Lateral rotation

Answer 15

anterior aspect of the limb rotates laterally

Question 16

Pronation

Answer 16

medial rotation of the forearm

Question 17

Supination

Answer 17

lateral rotation of the forearm

Question 18

Limitations of movement

Answer 18

1. shape of the articulating surfaces
2. ligaments and capsule at the joint
3. muscles that act on the joint

Question 19

How synovial joints are classified

Answer 19

1. synovial joints are classified according to the shapes of the articular surfaces of the constituent bones
2. the shape is responsible for the type of movement allowed at the joint and the range of movement

Question 20

Plane (synovial joint)

Answer 20

a. articular surfaces almost flat
b. allows sliding or gliding movements
c. example: between carpal and tarsal bones

Question 21

Hinge (gingylmus)

(synovial joint)

Answer 21

a. articular surfaces present 1 or more convex projections fitting in a concave surface or surfaces
b. allows movements of flexion and extension in 1 plane (sagittal plane)
c. example: elbow, interphalangeal, knee and ankle joints

Question 22

Pivot (trochoid)

synovial joint

Answer 22

a. articular surfaces present a rounded projection rotating within a concave depression
b. allows movements of medial and lateral rotation around a longitudinal axis
c. example: between radius and ulna (radioulnar joint)

Question 23

condyloid (ellipsoidal)

synovial joint

Answer 23

a. articular surfaces present a conyloid(round) projection fitting into a concave depression
b. allows movements of flexion, extension, abduction, and adduction in 2 planes (frontal and sagittal planes and circumduction)
c. example: wrist joint

Question 24

Saddle (sellar)

synovial joint

Answer 24

a. articular surfaces are reciprocally concave- convex
i. each articular surface presents both a concave surface and a convex surface
ii. when the articular surfaces of these 2 bones are joined, the concave and convex surfaces of the first bone simultaneously fit into the respective convex and concave surfaces of the second bone
b. allows movements of flexion, extension, abduction and abbduction in 2 planes plus rotation
c. example: carpometacarpal joint of the thumb

Question 25

Ball and socket (spheroid)

synovial joint

Answer 25

a. articular surfaces present a spherical surface of 1 bone moving within a socket of the other bone
b. allows movements of flexion, extension, abduction, adduction, circumduction, and rotation in an infinite number of planes
c. example: shoulder and hip

Question 26

Rule of stability of a joint

Answer 26

As the degree of freedom of moment increase the stability of the joint decreases

Question 27

Bursa

Answer 27

from Greek: bursa=purse

a bursa is a small connective tissue sac lined w a synovial membrane. It contains a synovial fluid

Question 28

Bursitis

Answer 28

inflammation of a bursa

Question 29

Function of a bursa

Answer 29

facilitates movement by minimizing friction between 2 moving structures

Question 30

Structure of a bursa

Answer 30

1. it is a small closed connective tissue sac lined with a secretory synovial membrane
2. it is filled w a clear viscous fluid, which is secreted by the synovial membrane
   a. the fluid is responsible for the cushioning effect of the bursa
3. an elongated bursa, which encloses a tendon, is called a SYNOVIAL SHEATH, which id often located between the tendons of the wrist and ankle and the retinacula (connective tissue structures that retain tendons) of the wrist and ankle

Question 31

List the joints from most stable to least stable

Answer 31

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Question 32

Location of a bursa

Answer 32

1. found between 2 structures, which move on 1 another, in which friction needs to be decreased
   a. between skin and bone
   i. example: elbow and knee
   b. between tendons and bone
   i. example: ankle
   c. between muscle and bone
   i. example: shoulder
   d. between tendon and retinacula
   i. example: wrist and ankle