Ch 9: Joints

Front 1

How do joints contribute to homeostasis?

Back 1

By holding bones together to allow for movement and flexibility.

Front 2

What is an articulation?

Aka. a joint or arthrosis

Back 2

= a point of contact between two bones
- between bone and cartilage, or between bone and teeth

Front 3

What does it mean when one bone "articulates" with another bone?

Back 3

Means that the bones form a joint.

Front 4

How are joints classified?

Back 4

They are classified based on:

1. Structure: anatomical characteristics

2. Function: type of movement they permit

Front 5

The STRUCTURAL classification of joints are based on what 2 criteria?

Back 5

1. the presence or absence of a synovial cavity (a space between the articulating bones)

2. the connective tissue type that binds the bones together

Front 6

Joints are structurally classified as one of 3 types.
What are they?
a. Does it have a synovial cavity?
b. What connective tissue binds is present?

Back 6

1. Fibrous joints:
a. no synovial cavity
b. dense irregular connective tissue that is rich in collagen fibers.
- permit little or no movement

2. Cartilaginous joints
a. no synovial cavity
b. hyaline cartilage or fibrocartilage

3. Synovial joints:
a. yes, has a synovial cavity
b. dense irregular connective tissue of an articular capsule, and often by accessory ligaments.

Front 7

Joints are functionally classified as one of 3 types:

Back 7

1. Synarthrosis (pl: synarthroses)
= An immovable joint

2. Amphiarthrosis (pl: plural is amphiarthroses)
= A slightly movable joint

3. Diarthrosis (pl: diarthroses)
= A freely movable joint
- all are synovial joints.
- have a variety of shapes
- permit several different types of movements.

Front 8

On what basis are joints classified?

Back 8

They are classified based on:

1. Structure: anatomical characteristics

2. Function: type of movement they permit

Front 9

Identify & describe the 3 types of fibrous joints.
a. What is it composed of?
b. Where does it occur? Example?
c. Is it synarthroses? Amphiarthroses? Diarthrosis?

Back 9

1. Sutures
a. A fibrous joint composed of a thin layer of dense irregular connective tissue
b. Only b/w bones of the skull. Ex. coronal suture b/w the parietal & frontal bones (Fig 9-1a)
c. Synarthroses
*The irregular, interlocking edges of sutures give them added strength and decrease their chance of fracturing.

2. Syndesmoses
a. A fibrous joint with greater distance b/w the articulating surfaces & more dense irregular connective tissue than in a suture; dense irregular connective tissue typically arranged as a bundle (ligament)
b. Distal tibiofibular joint (where the anterior tibiofibular ligament connects the tibia and fibula (Figure 9-1b, left); Gomphoses (next slide)
c. Amphiarthrosis

3. Interroseous membranes
a. A substantial sheet of dense irregular connective tissue that binds neighboring long bones
b. b/w long bones. Ex. b/w radius & ulna in forearm (Fig 8.6a, b, p. 241); b/w tibia & fibula in leg (Fig 9-1c)
d. Amphiarthrosis

Front 10

a.What is a gomphosis/ dentoalveolar joint?
b.Where does it occur?
c. Is it synarthroses? Amphiarthroses? Diarthrosis?

Back 10

a.An example of a syndesmosis in which a cone-shaped peg fits into a socket.

b.Articulations b/w the roots of teeth & their sockets (alveoli) in the maxillae & mandible (Fig 9-1b)

c.Synarthrosis

Front 11

Functionally, why are sutures classified as synarthroses, and syndesmoses as amphiarthroses?

Back 11

Functionally, sutures are classified as synarthroses because they are immovable; syndesmoses are classified as amphiarthroses because they are slightly movable.

Front 12

Identify and describe the 2 types of cartilaginous joints:
a. What is its structure?
b. Examples?
c. Is it synarthrosis? Amphiarthrosis?

Back 12

1.Synchodroses
a. A cartilaginous joint in which the connecting material is hyaline cartilage.
b. Epiphyseal (growth) plate that connects the epiphysis & diaphysis of a growing bone (Fig 9-2a); Joint b/w the first rib and manubrium of sternum
* When bone elongation ceases, bone replaces the hyaline cartilage, and the synchondrosis becomes a synostosis, a bony joint.
c. Synarthrosis

2.Symphyses
a. A cartilaginous joint in which a broad, flat disc of fibrocartilage connects the bones.
b. Pubic symphysis between the anterior surfaces of the hip bones (Figure 9-2b); At junction of manubrium & body of sternum (Fig 7.22); At intervertebral joints b/w the bodies of vertebrae (Fig 7.20a, p. 224). A portion of the intervertebral disc is composed of fibrocartilage
*all symphyses occur in midline of body.
c. Amphiarthrosis

Front 13

What is the structural difference between a synchondrosis and a symphysis?

Back 13

The type of cartilage that holds the joint together:
Hyaline cartilage in a synchondrosis
Fibrocartilage in a symphysis

Front 14

What characteristics make synovial joints different from other joints?

Back 14

1.Synovial (joint) cavity: between the articulating bones (Fig 9-3)
2.Classified functionally as diarthroses (synovial cavity allows a joint to be freely movable)
3.Bones at synovial joint covered by articular cartilage (= a layer of hyaline cartilage)

Front 15

What are the 3 functions of articular cartilage?

Back 15

1. Covers the articulating surface of the bones with a smooth, slippery surface;does not bind them together.

2. Reduces friction between bones in the joint during movement

3. Helps to absorb shock.

Front 16

What is the articular capsule composed of?

What is its function?

Back 16

Composed of 2 layers: outer fibrous membrane & an inner synovial membrane (Fig 9-3)

-Surrounds a synovial joint
-Encloses the synovial cavity
-Unites the articulating bones

Front 17

What are the outer fibrous membrane and inner synovial membrane and composed of?

Back 17

Fibrous - dense irregular connective tissue (mostly collagen fibers)
Synovial - areolar connective tissue with elastic fibers

Front 18

How does the dense irregular connective tissue (mostly collagen fibers) contribute to the function of the fibrous membrane?

Back 18

-Allows for flexibility in the fibrous membrane: permits considerable movement at a joint while its great tensile strength (resistance to stretching) helps prevent the bones from dislocating

Front 19

The fibers of some fibrous membranes are arranged as dense regular connective that are highly adapted for resisting strains. What are these bundles called? What is its importance?

Back 19

=Ligaments
-It is one of the principal mechanical factors that hold bones together in a synovial joint.

Front 20

What does the synovial membrane secrete?
a.What does this secretion look like?
b.What is its functions?

Back 20

Synovial fluid

a. a viscous, clear or pale yellow fluid

b.
1. forms a thin film over the surface within the articular capsule

2. Reduces friction by lubricating the joint

3. Absorbs shocks

4. Supplies oxygen and nutrients to and removes carbon dioxide and metabolic wastes from the chondrocytes within articular cartilage.
*Recall that cartilage is an avascular tissue, so it does not have blood vessels to perform the latter function.)

5. Contains phagocytic cells that remove microbes and the debris that results from normal wear and tear in the joint.

Front 21

What happens to a synovial joint as joint movement/ exercise increases?

Back 21

-Production & secretion of synovial fluid is stimulated
*More fluid means less stress on the joints during exercise

Front 22

Many synovial joints also contain accessory ligaments.

a. What are the 2 types?

b. Where are they located in respect to the articular capsule?

Back 22

a. Extracapsular ligament: lies outside the articular capsule

Intracapsular ligament: occurs within the articular capsule

Ex. (Fig 9-15d)

b. Extra: fibular and tibial collateral ligaments of the knee joint

Intra: anterior and posterior cruciate ligaments of the knee joint

Front 23

Inside some synovial joints (ie. knee), pads of fibrocartilage lie between the articular surface of the bones and are attached to the fibrous capsule/membrane.

a. What are these pads called?

b. What are their 4 functions?

Back 23

a. Articular discs/ menisci

b.
1. Subdivide the synovial cavity into 2 spaces, allowing separate movements to occur in each space.

2. Modify shape of joint surfaces of articulating bones to allow 2 bones of different shapes fit together more tightly.

3. Help to maintain the stability of the joint

4. Direct the flow of synovial fluid to area of greatest friction
Ex. (Fig 9-15d) lateral and medial menisci in knee joint

Front 24

The nerves that supply a joint are the same as those that supply the skeletal muscles that move the joint. Synovial joints contain many nerve endings that are distributed to the articular capsule and associated ligaments.

What are 3 things that different areas of nerve endings do?

Back 24

Some:

1.convey information about pain from one joint to the spinal cord & brain for processing

2.respond to the degree of movement and stretch at a joint

3.send impulses from the spinal cord and brain to the muscles to adjust the body movements.

(These are not necessarily the same nerves that send the information to the spinal cord and brain).

Front 25

Many components of synovial joints are avascular, but nearby arteries and veins send out numerous branches that penetrate the ligaments and articular capsule to do what?

Back 25

Arteries deliver oxygen and nutrients to the joints.

Veins remove carbon dioxide and wastes from the joints.

Front 26

How do the chondrocytes in the articular cartilage of a synovial joint receive oxygen and nutrients, and remove carbon dioxide and wastes?

Back 26

Oxygen and nutrients pass from:
blood --> synovial fluid --> chondrocytes
(*All other joint tissues supplied directly by capillaries)

Carbon dioxide and wastes pass from:
chondrocyte --> synovial fluid --> veins

Front 27

What 2 structures are used to reduce friction at joints?

Back 27

Bursae & tendon sheaths


*Bursae are not strictly part of synovial joints, but they do resemble joint/ articular capsules because their walls consist of connective tissue lined by a synovial membrane. They are filled with a small amount of fluid that is similar to synovial fluid.

Front 28

Bursae:
a.What is their structure?
b. Where are they located?
c. What is their function?

Back 28

a. sac-like structures situated to alleviate friction in some joints (ex. Shoulder & knee joints Fig 9-12 & 9-15)
- filled with a small amount of fluid similar to synovial fluid
- walls consist of connective tissue lined by a synovial membrane (resemble joint capsules)

b. Between the skin & bones, tendons & bones, muscles & bones, or ligaments & bones.

c. fluid-filled sacs cushion the movement of the above body parts against one another.

Front 29

Tendon (synovial) sheaths
a. What is their structure?
b. Where are they located?
c. What is their function?

Back 29

a. Tube-like bursae that wrap around certain tendons that experience considerable friction

b. Where tendons pass through synovial cavities (ie. Tendon of the bicep muscle at shoulder joint Fig 9-12c, wrist & ankle where many tendons come together in a confined space Fig 11-18, fingers & toes where there is lots of movement Fig 11-18)

Front 30

How are bursae different from joint (articular) capsules?

Back 30

Bursae:
- sac like structures filled with a small amount of fluid similar to synovial fluid
- between the skin & bones, tendons & bones, muscles & bones, or ligaments & bones.


Joint Capsules:
- composed of 2 layers: outer fibrous membrane & an inner synovial membrane (Fig 9-3)
- unites articulating bones & encloses the synovial cavity

Front 31

What are the 4 major categories of movements that occur at synovial joints?

Back 31

1. Gliding
2. Angular movements
3. Rotation
4. Special movements.

Front 32

What is gliding?
a.What are two examples of joints that permit gliding movements?

Back 32

= Movement of relatively flat bone surfaces back-and-forth and side-to-side over one another; little change in the angle between bones.

a. intercarpal & intertarsal joints

Front 33

What is an angular movement?
a.Identify the major angular movements and define them.

Back 33

= Increase or decrease in the angle between articulating bones

a. “FELHAAC”

Flexion = Decrease in the angle between articulating bones, usually in the sagittal plane.

Extension = Increase in the angle between articulating bones, usually in the sagittal plane.

Lateral Flexion = Movement of the trunk in the frontal plane.

Hyperextension = Extension beyond the anatomical position.

Abduction = Movement of a bone away from the midline, usually in the frontal plane.

Adduction = Movement of a bone toward the midline, usually in the frontal plane.

Circumduction = Flexion, abduction, extension, and adduction in succession, in which the distal end of a body part moves in a circle.

Front 34

What is rotation?

Back 34

= Movement of a bone around its longitudinal axis; in the limbs, it may be medial (toward midline) or lateral (away from midline).

Front 35

How do medial and lateral rotation differ?

Back 35

The anterior surface of a bone or limb rotates toward the midline in medial rotation, and away from the midline in lateral rotation.

Front 36

What is a special movement?
Identify the different types of special movements and define them.

Back 36

= Occurs at specific joints.
"EDPRIEDPSPO"

Elevation: Superior movement of a body part.

Depression: Inferior movement of a body part.

Protraction: Anterior movement of a body part in the transverse plane.

Retraction: Posterior movement of a body part in the transverse plane.

Inversion: Medial movement of the sole.

Eversion: Lateral movement of the sole.

Dorsiflexion: Bending the foot in the direction of the dorsum (superior surface).

Plantar flexion: Bending the foot in the direction of the plantar surface (sole).

Supination: Movement of the forearm that turns the palm anteriorly.

Pronation: Movement of the forearm that turns the palm posteriorly.

Opposition: Movement of the thumb across the palm to touch fingertips on the same hand.

Front 37

Synovial joints are similar in structure but they are divided into 6 categories based on what characterstic?

Back 37

Based on the shape of the articulating surfaces & movement.

Front 38

Identify and define the 6 types of synovial joints:

Back 38

“PHPCSB” “Pent House Pacific Centre B S”

Planar: Articulated surfaces are flat or slightly curved.

Hinge: Convex surface fits into a concave surface

Pivot: Rounded or pointed surface fits into a ring formed partly by bone and partly by a ligament.

Condyloid: Oval-shaped projection fits into an oval-shaped depression.

Ball-and-socket: Ball-like surface fits into a cuplike depression.

Saddle: Articular surface of one bone is saddle-shaped, and the articular surface of the other bone “sits” in the saddle.

Front 39

**Look at TABLE 9-2: Summarizes the structural and functional categories of joints!!!!

Back 39

**Look at TABLE 9-2: Summarizes the structural and functional categories of joints!!!!

Front 40

The knee joint (tibiofemoral joint) is the largest and most complex joint of the body. It is a modified hinge joint that consists of three joints within a single synovial cavity. What are they?

Back 40

1. Lateral tibiofemoral joint
= between the lateral condyle of the femur, lateral meniscus, and lateral condyle of the tibia, which is weight-bearing.

2. Medial tibiofemoral joint
= between the medial condyle of the femur, medial meniscus, and medial condyle of the tibia.

3. Intermediate patellofemoral joint
= between the patella and the patellar surface of the femur.

Front 41

Describe the anatomy of the following anatomical components of the knee joint:
1.Tibial collateral ligament.
2 Fibular collateral ligament.
3. Intracapsular ligaments: ACL and PCL
4. Articular discs (menisci): medial & lateral meniscus

Back 41

1.Tibial collateral ligament. Broad, flat ligament on the medial surface of the joint that extends from the medial condyle of the femur to the medial condyle of the tibia (Figure 9-15a, b, d).

2.Fibular collateral ligament. Strong, rounded ligament on the lateral surface of the joint that extends from the lateral condyle of the femur to the lateral side of the head of the fibula (Figure 9-15a, b, d); Strengthens the lateral aspect of the joint.


3.Intracapsular ligaments. Ligaments within the capsule that connect the tibia and femur. The anterior and posterior cruciate ligaments (KROO-shē-āt = like a cross) are named based on their origins relative to the intercondylar area of the tibia. From their origins, they cross on their way to their destinations on the femur.
a. Anterior cruciate ligament (ACL). Extends posteriorly and laterally from a point anterior to the intercondylar area of the tibia to the posterior part of the medial surface of the lateral condyle of the femur (Fig 9-15d)
- limits hypere

Front 42

What is arthroplasty?

Back 42

= A surgical procedure in which severely damaged joints damaged by diseases (ie. Arthritis or injury) are replaced with artificial joints.

Front 43

Define: Rheumatism

a. Identify and define a form of Rheumatism

Back 43

Any painful disorder of the supporting structures of the body—bones, ligaments, tendons, or muscles—that is not caused by infection or injury.

a. Arthritis is a form of rheumatism
= joints are swollen, stiff, and painful.

Front 44

Define: Osteoarthritis (OA)
a. What does it result from?

Back 44

= A degenerative joint disease in which joint cartilage is gradually lost; articular cartilage deteriorates; synovial membrane

a. Results from a combination of aging, obesity, irritation of the joints, muscle weakness, and wear and abrasion.

*Commonly known as “wear-and-tear” arthritis

*Most common type of arthritis.

Front 45

What are 2 major distinctions between osteoarthritis and rheumatoid arthritis?

Back 45

Osteoarthritis first afflicts the larger joints (knees, hips) and is due to wear and tear.

Rheumatoid arthritis first strikes smaller joints and is an active attack of the cartilage.

Front 46

What is Rheumatoid arthritis (RA)?

a.What symptoms characterize RA?

Back 46

= An autoimmune disease in which the immune system of the body attacks its own tissues— cartilage and joint linings.

a.Inflammation of the joint, causing swelling, pain, and loss of function.
*Usually, this form of arthritis occurs bilaterally: If one wrist is affected, the other is also likely to be affected, although often not to the same degree.

Front 47

What is Gouty Arthritis?

Back 47

= Sodium urate crystals are deposited in the soft tissues of the joints; Crystals irritate and erode the cartilage, causing inflammation, swelling, and acute pain. Eventually, the crystals destroy all joint tissues.

- Affects joints of feet, esp. base of big toe.

If untreated, ends of articulating bones fuse & joint becomes immovable.