Chapter 8: joints of the skeletal system objectives



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CHAPTER 8: JOINTS OF THE SKELETAL SYSTEM

OBJECTIVES:
1. Define the term articulation.
2. Distinguish between the functional and structural classification of joints, and relate the terms that are essentially synonymous.
3. Compare and contrast the terms synarthrosis, amphiarthrosis and diarthrosis and give examples of each.
4. Name the three types of fibrous joints and give an example of each.
5. Identify the difference between the epiphyseal plate and an intervertebral disc.
6. Sketch a typical synovial joint labeling all structures. Then in text form, discuss the function of each of the labeled structures.
7. Name the components and functions of synovial fluid.
8. Define the terms fatty pads, articular discs, and bursa, and name a key location for each.
9. List and discuss three factors that influence the stability of a synovial joint.
10. Distinguish between the origin and insertion of a muscle.
11. Name the three general types of movements allowed by joints.
12. List the angular movements allowed by synovial joints and give examples of each.
13. Identify the special movements allowed by the joints of the radius and ulna, foot, and shoulders.
14. Name the six types of synovial joints and give an example of each.
15. Explain how an intervertebral disc can be all of the following: an amphiarthrosis, cartilaginous joint, symphysis, gliding joint, and plane joint.
16. Discuss some important joint disorders.

Definition: Joint (articulation) = site where two bones come together.


CLASSIFICATION OF JOINTS

I. Functional Classification of Joints:


A. Based on the amount of movement allowed.

B. 3 types:


1. Synarthroses = immovable joints.

a. Example = sutures of skull.


2. Amphiarthroses = slightly movable joints.

a. Example = intervertebral discs between vertebrae.


3. Diarthroses = freely movable joints.

a. Examples = joints of appendicular skeleton.


II. Structural Classification of Joints:
A. Based on material, which joins bones (between bones).

B. 3 types: Fibrous, Cartilaginous, Synovial


1. Fibrous Joints = joints composed of fibrous tissue; no joint cavity is present; 3 types:
a. Sutures = short fibrous CT fibers;

See Fig 8.2 and Fig 8.3, page 255.




  • synarthroses.

  • Only found in skull

b. Syndesmosis = cord of fibrous tissue called a ligament;




  • amphiarthroses with "give" but no true movement;

  • Example = distal tibiofibular joint.

  • See Fig 8.1, page 254.

c. Gomphosis = tooth within its bony socket; (alveolar fossa)



  • short periodontal ligament.

  • See Fig 8.4, page 256.

II. Structural Classification of Joints:
B. 3 types: Fibrous, Cartilaginous, Synovial
2. Cartilaginous Joints = joints composed of cartilage; no joint cavity;

2 types:
a. Synchondrosis = a plate of hyaline cartilage;



  • sites of bone growth during youth;

          • eventually ossify = synarthrotic;

          • Examples

  1. joint between the first rib and manubrium (See Fig 8.5, page 256) and

  2. the epiphyseal plate.

b. Symphysis = pad or plate of fibrocartilage;



          • compressible "shock absorber";

          • limited movement = amphiarthroses;

          • Examples

  1. intervertebral discs and

  2. symphysis pubis.

    • See Fig 8.6, page 256.

3. Synovial Joints = fluid-filled joint cavity; free movement = diarthrosis;


III. GENERAL STRUCTURE OF A SYNOVIAL JOINT = 5 distinct features:

See Fig 8.7, page 257.


A. Articular cartilage = hyaline cartilage covers the surface of each bone;
B. Joint cavity = a potential space between the two bones, filled with synovial fluid;
C. Articular capsule = double layered capsule surrounding cavity:

1. External, tough flexible fibrous capsule (continuous with periosteum of the bones);

2. Synovial membrane = loose CT lining of fibrous capsule, that also covers all internal joint surfaces excluding hyaline cartilage;
D. Synovial fluid = viscous lubricating fluid within cavity.

1. reduces friction between cartilages of 2 bones;

2. provide "weeping lubrication";

3. nourish cartilage;

4. contain phagocytes.
E. Reinforcing ligaments = ligaments that strengthen joint.

1. Definition: A ligament joins a bone to another bone across a synovial joint.

2. usually thickened portions of fibrous capsule (intrinsic or capsular);

III. GENERAL STRUCTURE OF A SYNOVIAL JOINT


F. Other joint features: See Fig 8.8, page 258.
1. fatty pads (hip & knee);
2. menisci or articular discs or that separate cavity into 2 compartments (knee, jaw, sternoclavicular).
3. bursa = flattened fibrous sacs with a synovial membrane and fluid that act as "ball bearings" to prevent friction on adjacent structures during joint activity;

a. cushion the movement of one body part over another;

b. located between skin and bone (where skin rubs over bone), and between muscle, tendons, ligaments and bone.
IV. TYPES OF SYNOVIAL JOINTS

See Figure 8.9, page 259. Also Table 8.1 page 260


A. Ball-and-socket joints = most freely movable joints; all angular movement;

1. The head of one bone fits into the socket of another;

2. Examples = hip and shoulder.
B. Condyloid joints = permit all angular motion, except rotation.

Examples = wrists and knuckles,


C. Gliding joints = cartilaginous joints;

Example = intervertebral discs.


D. Hinge joints = permit flexion & extension only;

Examples = elbow and knee.


E. Pivot joints = permit rotation;

Example = first intervertebral joint (atlantoaxial joint)


F. Saddle joints = thumb;

V. TYPES OF JOINT MOVEMENTS:


A. Definitions:
1. Origin = part of muscle attached to the immovable bone;
2. Insertion = part of a muscle attached to the movable bone;
* When a muscle contracts across a joint, its insertion is pulled toward its origin.
B. Three general types of movement:

1. Gliding movements = when flat bone surfaces glide or slide over one another.


a. occur at cartilaginous joints;

b. Examples = intervertebral discs and sternoclavicular joints.


2. Angular movements = changes in angles between bones; occur only at synovial joints.
a. Flexion = decreasing the angle between 2 bones.


  • Example = head toward chest.

1. Dorsiflexion = bringing foot closer to shin.


2. Plantar flexion = pointing one's toe (flexion toward the sole).

b. Extension = increasing the angle between 2 bones.




  • Example = straightening a flexed neck.

1. Hyperextension = increasing the angle greater than 180o;


See Figure 8.10, page 261.

V. TYPES OF JOINT MOVEMENTS:


B. Three general types of movement: (continued)
2. Angular Movements of Synovial Joints (continued)
c. Abduction = moving a limb away from the midline.


  • Example = raising arm or thigh laterally;

d. Adduction = moving a limb toward the midline.

See Fig 8.10, page 261 to see the above examples.
e. Circumduction = moving a limb in a circular (cone-shaped) manner.
f. Rotation = turning movement of a bone along its long axis.


  • Example = atlas over axis (i.e. “just say no”).

  • Example = shoulder and hip joint.

  • See Fig 8.11, page 262 to see the above examples.

3. Special Movements = those at specific joints


See Figures 8.11 and 8.12, page 262.
a. supination/pronation = movements between the radius and ulna at the proximal radioulnar joint

          • thumb up = supination;

          • thumb down = pronation;

b. inversion/eversion = movement of foot;



  • sole inward = inversion;

  • sole out = eversion;

c. elevation/depression:



  • shoulder shrug = elevation;

  • mandible in opening mouth = depression.

d. protraction/retraction:




VII. EXAMPLES OF SYNOVIAL JOINTS
A. Shoulder joint (2 joints) See figures 8.13, 8.14 pages 264-265.

1. Ball and socket is the glenohumeral joint



  • joins Glenoid cavity and head of humerus

2. Syndesmosis is called the acromioclavicular joint



  • acromial end of clavicle and the acromion process of the scapula

3. Ball and socket is surrounded by many reinforcing ligaments and tendons collectively called the rotator cuff


4. Many bursa also lubricate the shoulder
5. Movement can occur in any angular plane
B. Elbow joint (2 joints) See figures 8.15, 8.16 page 266
1. Hinge is between trochlea of humerus and trochlear notch of ulna
2. Gliding joint is between capitulum of humerus and head of radius
3. Very stable joint with many reinforcing ligaments
4. Only allows flexion and extension
C. Hip joint (coxal joint) See figures 8.18, 8.19 page 268.
1. Ball and socket between head of femur and acetabulum of coxa
2. Contains many large reinforcing ligaments
3. Allows same movements as shoulder, but with less range due to bony limitations

VII. EXAMPLES OF SYNOVIAL JOINTS


D. Knee (3 joints) See figures 8.20 , 8.21 page 270.

1. Largest, most complex joint


2. Functions as a hinge even though 3 joints work together
3. Medial condyles of femur and tibia make one condyloid joint
4. Lateral condyles of femur and tibia make another condyloid joint
5. Patellar surface of femur and patella make a gliding joint
6. Flexion and extension with some slight rotation
7. Contains many reinforcing structures
a. Extracapsular ligaments – found outside joint capsule

  • patellar ligament

  • tibial (medial) collateral ligament; MCL

  • fibular (lateral) collateral ligament; LCL

b. Intracapsular ligaments – found inside joint capsule

  • anterior cruciate ligament; ACL

  • posterior cruciate ligament; PCL

  • prevent hyperextension

c. Menisci

  • medial meniscus

  • lateral meniscus

  • C-shaped fibrocartilage pads

  • Reshape the tibial condyles for a better fit

  • Absorb shock

d. Many bursae
VIII. LIFE SPAN CHANGES

A. Fontanels of skull harden in first 2 years

B. Epiphyseal plates harden from ages 14-20 years.

C. Fibrocartilage loses water, decreasing flexibility of intervertebral joints and knees

D. Collagen changes causing stiffening beginning at age 30.

E. Exercise decreases onset of joint stiffening.


IX Homeostatic Imbalances of Joints
A. Gout. See introduction on page 254.
B. Benign joint hypermobility syndrome. See blue box on page 257.
C. Dislocation. See blue box on page 265.
D. Joint Replacement. See Clinical Application 8.1 on page 269.
E. Joint Disorders. . See Clinical Application 8.2 on pages 272.
F. Table 8A: Different Types of Arthritis, page 273.
X. Clinical Terms Related to the Joints

See page 274.



XI. JOINT SUMMARY TABLE: (Examples keyed at the end of this outline)

See Table 8.2 page 263.



NAME OF JOINT










STRUCTURAL CLASSIFICATION

OF JOINT










FUNCTIONAL CLASSIFICATION OF JOINT










BONES INVOLVED IN ARTICULATION










SPECIFIC MOVEMENTS ALLOWED BY JOINT










CLASSIFICATION OF JOINT BASED ON MOVEMENTS ALLOWED








XI. JOINT SUMMARY TABLE: (Examples keyed at the end of this outline)

See Table 8.2 page 263.



NAME OF JOINT










STRUCTURAL CLASSIFICATION

OF JOINT










FUNCTIONAL CLASSIFICATION OF JOINT










BONES INVOLVED IN ARTICULATION










SPECIFIC MOVEMENTS ALLOWED BY JOINT










CLASSIFICATION OF JOINT BASED ON MOVEMENTS ALLOWED








XI. JOINT SUMMARY TABLE: (Examples keyed at the end of this outline)

See Table 8.2 page 263.



NAME OF JOINT










STRUCTURAL CLASSIFICATION

OF JOINT










FUNCTIONAL CLASSIFICATION OF JOINT










BONES INVOLVED IN ARTICULATION










SPECIFIC MOVEMENTS ALLOWED BY JOINT










CLASSIFICATION OF JOINT BASED ON MOVEMENTS ALLOWED








XI. JOINT SUMMARY TABLE: (Examples keyed at the end of this outline)

See Table 8.2 page 263.


NAME OF JOINT

HIP

SUTURE

SYMPHYSIS PUBIS


STRUCTURAL CLASSIFICATION

OF JOINT

SYNOVIAL

FIBROUS

CARTILAGINOUS

(SYMPYSIS OF FIBRO-CARTILAGE)



FUNCTIONAL CLASSIFICATION OF JOINT

DIARTHROTIC

SYNARTHROTIC

AMPHI-ARTHROTIC


BONES INVOLVED IN ARTICULATION

HEAD OF FEMUR WITH ACETABULUM OF COXAL

SKULL BONES

PUBIS PORTIONS OF COXAL BONES


SPECIFIC MOVEMENTS ALLOWED BY JOINT

FLEXION, EXTENSION, ABDUCTION, ADDUCTION, CIRCUMDUCTION, ROTATION

NONE

GLIDING



CLASSIFICATION OF JOINT BASED ON MOVEMENTS ALLOWED

BALL –N- SOCKET

N/A

PLANE




Chapter 8: Joints of the Skeletal System




I. Introduction


A. Joints are also called articulations.

B. Joints bind parts of the skeletal system, make possible bone growth, permit parts of the skeleton to change shape during childbirth and enable the body to move in response to skeletal muscle contractions.


II. Classification of Joints


A. Introduction

1. Three general groups of joints are fibrous, cartilaginous, and synovial.

2. Joints can also be grouped according to the degree of movement possible at the bony junctions.

3. Immovable joints are called synarthrotic.

4. Slightly movable joints are called amphiarthrotic.

5. Freely movable joints are called diarthrotic.

B. Fibrous Joints

1. Fibrous joints are so named because the dense connective tissue holding them together contains many collagenous fibers.

2. The three types of fibrous joints are syndesmosis, suture, and gomphosis.

3. In syndesmois, bones are bound together by long fibers of connective tissue that form an interosseous ligament.

4. An example of a syndesmosis is at the distal ends of the tibia and fibula, where they join to form the tibiofibular articulation.

5. Because a syndesmosis permits slight movement, it is called amphiarthrotic.

6. Sutures are only between flat bones of the skull.

7. A sutural ligament is thin layer of dense connective tissue that joins flat bones of the skull together.

8. Fontanels allow the skull to change shape slightly during childbirth.

9. An example of a suture is the parietal suture.

10. Because sutures are immovable, they are called synarthrotic.

11. A gomphosis is a joint formed by the union of a cone-shaped bony process in a bony socket.

12. A periodontal ligament is a structure that firmly attaches a tooth to the jaw.

13. An example of a gomphosis is a tooth in a socket.

C. Cartilaginous Joints

1. Bones of cartilaginous joints are joined by hyaline cartilage or fibrocartilage.

2. Two types of cartilaginous joints are synchondroses, and symphyses.

3. In a synchondrosis, bands of hyaline cartilage unite bones.

4. Many synchondroses are temporary structures and disappear during growth.

5. Two examples of synchondroses are epiphyseal plates and the joint between the first rib and manubrium.

6. Synchondroses do not permit movement and are therefore synarthrotic.

7. In a symphysis, the articular surfaces of bones are covered with a thin layer of hyaline cartilage and the cartilage is attached to a pad of springy fibrocartilage.

8. Two examples of symphyses are the symphysis pubis and intervertebral joints.

D. Synovial Joints

1. Most joints are synovial.

2. Synovial joints allow free movement and are called diarthrotic.

3. Synovial joints consist of articular cartilage, a joint capsule, and a synovial membrane

III. General Structure of a Synovial Joint


A. Articular cartilage is a thin layer of hyaline cartilage that covers the ends of bones.

B. The joint capsule is a tubular structure that holds together the bones of a synovial joint.

C. The outer layer of the joint capsule consists of dense connective tissue.

D. The inner layer of the joint capsule consists of a synovial membrane.

E. Ligaments reinforce the joint capsule.

F. The synovial membrane is a shiny, vascular layer of loose connective tissue.

G. Synovial fluid comes from the synovial membrane.

H. Besides secreting synovial fluid, the synovial membrane may also store adipose tissue and form movable fatty pads with the joint.

I. Synovial fluid has a consistency of uncooked egg white and functions to moisten and lubricate the smooth cartilaginous surfaces within the joint.

J. Menisci are discs of fibrocartilage.

K. Menisci function to cushion articulating surfaces.

L. Bursae are fluid filled sacs associated with synovial joints.

M. Bursae are located between the skin and underlying bony prominences.

N. Bursae function to cushion and aid the movement of tendons that glide ofver bony parts of over other tendons.

O. The names of bursae reflect locations.

IV. Types of Synovial Joints


A. The six major types of synovial joints are ball-and-socket, condyloid, gliding, hinge, pivot, and saddle.

B. A ball-and-socket joint consists of a bone with a globular head that articulates with a cup-shaped cavity of another bone.

C. A ball-and-socket joint allows a wider range of motion than any other type of joint.

D. Examples of ball-and-socket joints are the hip joint and shoulder joint.

E. The structure of a condyloid joint is an ovoid condyle of one bone fitting into the elliptical cavity of another bone.

F. An example of a condyloid joint is between the metacarpals and phalanges.

G. The articulating surfaces of gliding joints are nearly flat or slightly curved.

H. Examples of gliding joints are joints within the wrists and ankles.

I. The structure of a hinge joint is a convex surface of one bone fitting into the concave surface of another bone.

J. An example of a hinge joint is the elbow joint.

K. The structure of a pivot joint is a cylindrical surface of one bone rotating within a ring formed of bone and fibrous tissue of a ligament.

L. Examples of pivot joints are the joint formed between the proximal ends of the radius and ulna, and the joint between the dens of the axis and ring of the atlas.

M. The structure of a saddle joint is a convex surface of one bone articulating with a concave surface of another bone.

N. An example of a saddle joint is the joint between the trapezium and the metacarpal of the thumb.


V. Types of Joint Movements


A. An insertion of a muscle is its movable end.

B. The origin of a muscle is its fixed end.

C. Flexion is bending of a body part.

D. Extension is straightening of a body part.

E. Hyperextension is excess extension of a body part beyond the anatomical position.

F. Dorsiflexion is bending of the foot at the ankle upward.

G. Plantar flexion is the bending of the foot downward at the ankle.

H. Abduction is moving a part away from the midline of the body.

I. Adduction is moving a part toward the midline of the body.

J. Rotation is moving a body part around an axis; also known as twisting.

K. Circumduction is moving a body part in a circular path.

L. Supination is turning the palm of the hand up.

M. Pronation is turning the palm of the down.

N. Eversion is turning the sole of the foot laterally.

O. Inversion is turning the sole of the foot medially.

P. Protraction is moving a body part forward.

Q. Retraction is moving a body part backward.

R. Elevation is raising a body part.

S. Depression is lowering a body part.

VI. Examples of Synovial Joints


A. Shoulder Joint

1. The shoulder joint is a ball-and-socket joint that consists of the rounded head of the humerus and the shallow glenoid cavity of the scapula.

2. The shoulder joint capsule is very loose.

3. Muscles and tendons reinforce the shoulder joint capsule.

4. The four ligaments that help prevent displacement of the shoulder joint are coracohumerual, glenohumeral, transverse humeral, and the glenoid labrum.

5. The coracohumeral ligament strengthens the superior portion of the joint capsule.

6. The glenohumeral ligament extends from the edge of the glenoid cavity to the lesser tubercle and the anatomical neck of the humerus.

7. The transverse humeral ligament runs between the lesser and the greater tubercles of the humerus.

8. The glenoid labrum functions to deepen the glenoid cavity.

9. The four major bursae associated with each shoulder joint are subscapular, subdeltoid, subacromial, and subcoracoid.

10. The shoulder joint is capable of a wide range of movement due to the looseness of its attachments and the relatively large atricular surface of the humeurs compared to the shallow depth of the glenoid cavity.

B. Elbow Joint

1. The articulations of the elbow joint are a hinge joint between the trochlea of the humerus and the trochlear notch of the ulna and a gliding joint between the capitulum of the humerus and a shallow depression on the head of the radius.

2. The ulnar collateral ligament is located on the medial wall of the capsule.

3. The ulnar collateral ligament attaches the medial epicondyle of the humerus to the medial margin of the coronoid process of the ulna; it also attaches the medial epicondyle of the humerus to the olecranon process of the ulna.

4. The radial collateral ligament is located between the lateral epidondyle of the humerus and the annular ligament of the radius.

5. The radial collateral ligament strengthens the lateral wall of the joint capsule.

6. Fatty pads of the elbow joint protect nonarticular bony areas during joint movements.

7. The only movements that occur at the elbow joint are flexion and extension.

C. Hip Joint

1. The hip joint is a ball-and-socket joint.

2. The hip joint consists of the head of the femur and the cup-shaped acetabulum.

3. The acetabular labrum is a ring of fibrocartilage and functions to deepen the cavity of the acetabulum.

4. The major ligaments of the hip joint are iliofemoral, pubofemoral, and ischiofemoral.

5. The iliofemoral ligament attaches the anterior inferior iliac spine to the intertrochanteric line.

6. The pubofemoral ligament extends between the superior portion of the pubis and the iliofemoral ligament.

7. The ischiofemoral ligament connects the ischium to the joint capsule.

8. The hip joint has less freedom of movement than the shoulder joint.

9. Muscles surround the capsule of the hip joint.

D. Knee Joint

1. The largest and most complex of the synovial joints is the knee joint.

2. The knee joint consists of the medial and lateral condyles at the distal end of the femur and the medial and lateral condyles at the proximal end of the tibia.

3. The femur articulates with the patella anteriorly.

4. The knee functions as a modified hinge joint.

5. The articulation between the femur and tibia is a condyloid joint.

6. The articulation between the femur and patella is a gliding joint.

7. The knee joint is greatly strengthened by ligaments and tendons of several large muscles.

8. The 5 ligaments of the knee joint are patellar, oblique popliteal, arcuate, tibial collateral, and fibular collateral.

9. The patellar joint extends from the margin of the patella to the tibial tuberosity.

10. The oblique popliteal ligament connects the lateral condyle of the femur to the margin of the head of the tibia.

11. The arcuate popliteal ligament connects the lateral condyle of the femur to the head of the fibula.

12. The tibial collateral ligament connects the medial condyle of the femur to the medial condyle of the tibia.

13. The fibular collateral ligament connects the lateral condyle of the femur to the head of the fibula.

14. Two ligaments within the knee joint are called cruciate ligaments.

15. The anterior cruciate ligament connects the anterior intercondylar area of the tibia to the lateral condyle of the femur.

16. The posterior cruciate ligament connects the posterior intercondylar area of the tibia to the medial condyle of the femur.

17. Two menisci separate the articulating surfaces of the femur and tibia.

18. Three bursae associated with the knee joint are suprapatellar, prepatellar, and infrapatellar.


VII. Life-Span Changes


A. Changes in collagen lie behind joint stiffness.

B. The fibrous joints are the first to change.

C. Synchondroses that connect epiphyses to diaphyses in long bones disappear as the skeleton grows.

D. Ligaments lose their elasticity as collagen fibers become more tightly cross-linked.

E. In the intervertebral discs, less water diminishes the flexibility of the vertebral column and impairs the ability of the discs to absorb shocks.

F. Loss of function of synovial joints begins in the third decade of life.



G. Fewer capillaries serving the synovial membrane slow the circulation of synovial fluid, and the membrane may become infiltrated with fibrous material and cartilage.

Chapter 8

Joints of the Skeletal System

Part A


  1. Define joint.

A joint is a functional junction between bones.

  1. Explain how joints are classified.

The type of tissue that binds the bones together at each junction can classify joints. They can also be classified according to the degree of movement possible at the bony junctions.

  1. Compare the structure of a fibrous joint with that of a cartilaginous joint.

A fibrous joint uses fibrous connective tissue to hold bones together that were in close contact with one another. A cartilaginous joint uses hyaline or fibrocartilage to hold the articulation together. Neither type allows much movement.

  1. Distinguish between a syndesmosis and a suture.

A syndesmosis is characterized by bone being bound together by long fibers of connective tissue that form an interosseous ligament. This type of joint has slight movement. A suture has a thin layer of fibrous connective tissue that forms the sutural ligament. This type of joint has no movement.

  1. Describe a gomphosis, and name an example.

A gomphosis is a joint formed by the union of a cone-shaped bony process in a bony socket. The peglike root of a tooth fastened to a jawbone by a periodontal ligament is such a joint.

  1. Compare the structures of a synchondrosis and a symphysis.

A synchondrosis uses bands of hyaline cartilage to unite to bones. Many of these joints are temporary structures that disappear during growth. This particular type of joint allows no movement. A symphysis has the articular surfaces of bones covered with hyaline cartilage that is attached to a pad of fibrocartilage. This particular type of joint allows a limited type of movement.

  1. Explain how the joints between adjacent vertebrae permit movement.

Each of these are symphysis joints. Between each vertebra, there is an intervertebral disk that is composed of a band of fibrocartilage that surrounds a gelatinous core. The disk absorbs shocks and helps equalize pressure between the vertebrae during body movement. As each disk is slightly flexible, the combined movements of many of the joints in the vertebral column allow the back to bend forward, to the side, or to twist.

  1. Describe the general structure of a synovial joint.

A synovial joint will include the following components:

  1. Articular cartilage—Thin layer of hyaline cartilage on the ends of the articulating bones.

  2. Joint capsule—Tubular structure that has two distinct layers. The outer layer is made up of dense fibrous connective tissue. The inner layer is a shiny vascular membrane called the synovial membrane.

  3. Synovial fluid—A clear viscous fluid secreted by the synovial membrane for lubrication of the joint.

  4. Ligaments—Bundles of tough collagenous fibers that serve to reinforce the joint capsule.

  5. Menisci—Disks of fibrocartilage found in some synovial joints that serve as shock absorbers.

  6. Bursae—Fluid-filled sacs that cushion and aid the movement of tendons within a synovial joint.

  1. Describe how a joint capsule may be reinforced.

Ligaments are used to bind the articular ends of bones together reinforcing the joint capsule. These can be thickenings in the fibrous layer of the joint capsule or accessory structures that are located outside of the joint capsule.

  1. Explain the function of the synovial membrane.

The synovial membrane covers all surfaces within the joint capsule, except the areas the articular cartilage covers. It fills spaces and irregularities within the cavity. It secretes synovial fluid. It may store adipose tissue. It also reabsorbs the synovial fluid.

  1. Explain the function of synovial fluid

Synovial fluid helps to cushion, moisten, and lubricate the smooth cartilaginous surfaces within the joint. It also supplies the articular cartilage with nutrients.

  1. Define meniscus.

A meniscus is a disk of fibrocartilage that occurs in some synovial joints dividing them into two compartments. It serves as a shock absorber and allows bony prominences to fit together easier.

  1. Define bursa.

A bursa is a fluid-filled sac associated with freely moveable joints.

  1. List six types of synovial joints, and name an example of each type.

Type Example

Ball-and-Socket Hip joint, shoulder joint

Condyloid Joints between the metacarpals and phalanges

Gliding Joints between the various bones of the wrist and ankle

Hinge Elbow joint, knee joint

Pivot Joint between the proximal end of the radius and ulna

Saddle Joint between the carpal and metacarpal of the thumb

  1. Describe the movements permitted by each type of synovial joint.

Type Type of Movement

Ball-and-Socket Movement in all planes, as well as rotational movement around a central axis.

Condyloid Variety of movement in different planes, but rotational movement is possible.

Gliding Sliding back and forth motion only.

Hinge Flexion and extension in one plane only.

Pivot Rotation around a central axis only.

Saddle Variety of movements.

  1. Name the parts that comprise the shoulder joint.

The shoulder joint consists of the head of the humerus and the glenoid cavity of the scapula.

  1. Name the major ligaments associated with the shoulder joint.

Coracohumeral ligament—Connects the coracoid process of the scapula to the greater tubercle of the humerus.

Glenohumeral ligament—Three binds of fibers that appear as thickenings in the ventral wall of the joint capsule and extend from the edge of the glenoid fossa to the lesser tubercle and the anatomical neck of the humerus.

Transverse humeral ligament—Runs between the greater and lesser tubercles of the humerus.

Glenoidal labrum—Attached along the margin of the glenoid fossa and forms a rim with a thick free edge that deepens the fossa.

  1. Explain why the shoulder joint permits a wide range of movements.

The shoulder joint permits a wide range of movements due to the looseness of it attachments and the relatively large articular surface of the humerus compared to the shallow depth of the glenoid fossa. The movements include flexion, extension, abduction, adduction, rotation, and circumduction.

  1. Name the parts that comprise the elbow joint.

The elbow joint includes the trochlea of the humerus, the trochlear notch of the ulna, the capitulum of the humerus, and a fovea on the head of the radius.

  1. Describe the major ligaments associated with the elbow joint.

Radial collateral ligament—Connects the lateral epicondyle of the humerus to the annular ligament of the radius.

Annular ligament—Connects the margin of the trochlear notch of the ulna and encircles the head of the radius.

Ulnar collateral ligament—Connects the medial epicondyle of the humerus to the medial margin of the coronoid process. It also connects posteriorly to the medial epicondyle of the humerus and to the olecranon process of the ulna.

  1. Name the movements permitted by the elbow joint.

The only movement permitted between the humerus and ulna are flexion and extension. The head of the radius, however, is free to rotate in the annular ligament, which allows pronation and supination of the hand.

  1. Name the parts that comprise the hip joint.

The hip joint consists of the head of the femur and the cup-shaped acetabulum of the coxal bone.

  1. Describe how the articular surfaces of the hip joint are held together.

Acetabular labrum—Horseshoe-shaped ring of fibrocartilage at the rim of the acetabulum and deepens the acetabular cavity encloses the head of the femur.

Iliofemoral ligament—Connects the anterior inferior iliac spine of the coxal bone to the intertrochanteric line between the greater and lesser trochanters of the femur.

Pubofemoral ligament—Extends between the superior portion of the pubis and the iliofemoral ligament.

Ischiofemoral ligament—Originates on the ischium just posterior to the acetabulum and blends with the fibers of the joint capsule.

  1. Explain why there is less freedom of movement in the hip joint than in the shoulder joint.

Muscles surround the joint capsule of the hip. The articulating parts of the hip are held more closely together than those of the shoulder, allowing considerably less freedom of movement.

  1. Name the parts that comprise the knee joint.

The knee joint consists of the medial and lateral condyles at the distal end of the femur, and the medial and lateral condyles at the proximal end of the tibia. The femur also articulates anteriorly with the patella.

  1. Describe the major ligaments associated with the knee joint.

Patellar ligament—Continuation of a tendon from the quadriceps muscle group that extends from the margin of the patella to the tibial tuberosity.

Oblique popliteal ligament—Connects the lateral condyle of the femur to the margin of the head of the tibia.

Arcuate popliteal ligament—Extends from the lateral condyle of the femur to the head of the fibula.

Tibial collateral ligament (medial collateral ligament)—Connects the medial condyle of the femur to the medial condyle of the tibia.

Fibular collateral ligament (lateral collateral ligament)—Connects the lateral condyle of the femur and the head of the fibula.

Anterior cruciate ligament (ACL)—Originates from the anterior intercondylar area of the tibia and extends to the lateral condyle of the femur.

Posterior cruciate ligament (PCL)—Connects the posterior intercondylar area of the tibia to the medial condyle of the femur.

  1. Explain the function of the menisci of the knee.

The menisci serve as shock absorbers. They also function to compensate for the differences in shapes between the surfaces of the femur and tibia.

  1. Describe the locations of the bursae associated with the knee.

Suprapatellar bursa—Located between the anterior surface of the distal end of the femur and the quadriceps muscle group above it.

Prepatellar bursa—Located between the patella and the skin.

Infrapatellar bursa—Located between the proximal end of the tibia and the patellar ligament.

  1. Describe the process of aging as it contributes to the stiffening of fibrous, cartilaginous, and synovial joints.

Joint stiffness is often the earliest sign of aging.

a. Collagen changes cause the feeling of stiffness.

b. Regular exercise can lessen the effects.

Fibrous joints are the first to begin to change and strengthen over a lifetime.

Synchondroses of the long bones disappear with growth and development.

Changes in symphysis joints of the vetebral column diminish flexiblility and decrease height.

Over time, synovial joints lose elasticity.

Part B


Match the movements in column I with the descriptions in column II.

I II

1. Rotation D. Moving part around an axis

2. Supination A. Turning palm upward

3. Extension F. Increasing angle between parts

4. Eversion E. Turning sole of foot outward

5. Protraction C. Moving part forward

6. Flexion B. Decreasing angle between parts

7. Pronation H. Turning palm downward

8. Abduction I. Moving part away from midline

9. Depression G. Lowering a part


Chapter 8: Joints of the Skeletal System




I. Introduction


A. Joints are also called

B. Joints bind _______________________, make possible ,

permit _____________________________ and enable

II. Classification of Joints


A. Introduction

1. Three general groups of joints are

2. Joints can also be grouped according to

3. Immovable joints are called

4. Slightly movable joints are called

5. Freely movable joints are called

B. Fibrous Joints

1. Fibrous joints are so named because

2. The three types of fibrous joints are

3. In syndesmois, bones are bound together by

4. An example of a syndesmosis is

5. Because a syndesmosis permits slight movement, it is called

6. Sutures are only between

7. A sutural ligament is

8. Fontanels allow

9. An example of a suture is

10. Because sutures are immovable, they are called

11. A gomphosis is

12. A periodontal ligament is

13. An example of a gomphosis is

C. Cartilaginous Joints

1. Bones of cartilaginous joints are joined by

2. Two types of cartilaginous joints are

3. In a , bands of hyaline cartilage unite bones.

4. Many synchondroses are and disappear during growth.

5. Two examples of synchondroses are

6. Synchondroses do not permit movement and are therefore

7. In a symphysis, the articular surfaces of bones are covered with

___________________ and the cartilage is attached to

8. Two examples of symphyses is

D. Synovial Joints

1. Most joints are

2. Synovial joints allow movement.

and are called

3. Synovial joints consist of


III. General Structure of a Synovial Joint


A. Articular cartilage is

B. The joint capsule is

C. The outer layer of the joint capsule consists of

D. The inner layer of the joint capsule consists of

E. Ligaments reinforce

F. The synovial membrane is

G. Synovial fluid comes from

H. Besides secreting synovial fluid, the synovial membrane may also

I. Synovial fluid has a consistency of and functions to

J. Menisci are

K. Menisci function to

L. Bursae are

M. Bursae are located

N. Bursae function to

O. The names of bursae reflect

IV. Types of Synovial Joints


A. The six major types of synovial joints are

B. A ball-and-socket joint consists of

C. A ball-and-socket joint allows than any other type of joint.

D. Examples of ball-and-socket joints are

E. The structure of a condyloid joint is

F. An example of a condyloid joint is

G. The articulating surfaces of are nearly flat or slightly curved.

H. Examples of gliding joints are

I. The structure of a hinge joint is

J. An example of a hinge joint is

K. The structure of a pivot joint is

L. Examples of pivot joints are

M. The structure of a saddle joint is

N. An example of a saddle joint is


V. Types of Joint Movements


A. An insertion of a muscle is

B. The origin of a muscle is

C. Flexion is

D. Extension is

E. Hyperextension is

F. Dorsiflexion is

G. Plantar flexion is

H. Abduction is

I. Adduction is

J. Rotation is

K. Circumduction is

L. Supination is

M. Pronation is

N. Eversion is

O. Inversion is

P. Protraction is

Q. Retraction is

R. Elevation is

S. Depression is

VI. Examples of Synovial Joints


A. Shoulder Joint

1. The shoulder joint is ___________________ that consists of

2. The shoulder joint capsule is very

3. reinforce the shoulder joint capsule.

4. The four ligaments that help prevent displacement of the shoulder joint are

5. The coracohumeral ligament strengthens

6. The glenohumeral ligament extends

7. The transverse humeral ligament runs between

8. The glenoid labrum functions to

9. The four major bursae associated with each shoulder joint are

10. The shoulder joint is capable of a wide range of movement due to

B. Elbow Joint

1. The articulations of the elbow joint are

2. The ulnar collateral ligament is located

3. The ulnar collateral ligament attaches

4. The radial collateral ligament is located

5. The radial collateral ligament strengthens

6. Fatty pads of the elbow joint protect

7. The only movements that occur at the elbow joint are

C. Hip Joint

1. The hip joint is a

2. The hip joint consists of

3. The acetabular labrum is

and functions to

4. The major ligaments of the hip joint are

5. The iliofemoral ligament attaches

6. The pubofemoral ligament extends between

7. The ischiofemoral ligament connects

8. The hip joint has movement than the shoulder joint.

9. surround the capsule of the hip joint.

D. Knee Joint

1. The largest and most complex of the synovial joints is the

2. The knee joint consists of

3. The femur articulates with anteriorly.

4. The knee functions as a

5. The articulation between the femur and tibia is a

6. The articulation between the femur and patella is a

7. The knee joint is greatly strengthened by

8. The 5 ligaments of the knee joint are

9. The patellar joint extends from

10. The oblique popliteal ligament connects

11. The arcuate popliteal ligament connects

12. The tibial collateral ligament connects

13. The fibular collateral ligament connects

14. Two ligaments within the knee joint are called

15. The anterior cruciate ligament connects

16. The posterior cruciate ligament connects

17. Two separate the articulating surfaces

of the femur and tibia.

18. Three bursae associated with the knee joint are




VII. Life-Span Changes


A. Changes in collagen lie behind

B. The joints are the first to change.

C. Synchondroses that connect disappear

as the skeleton grows.

D. Ligaments lose ____________________ as collagen fibers become

E. In the intervertebral discs, less water diminishes

F. Loss of function of synovial joints begins in the decade of life.

G. Fewer serving the synovial membrane slows the circulation of

, and the membrane may become infiltrated with

H. Abduction is

I. Adduction is

J. Rotation is

K. Circumduction is

L. Supination is






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