Week 6 - Joints

Question 1

What is a joint

Answer 1

Site where 2 or more bones connect
Also referred to as an articulation

Question 2

Which bones come together to make the knee

Answer 2

Femur
Patella
Tibia
Fibula

Question 3

Why do we have joints

Answer 3

To link the skeletal system (we are a fully articulated joined skeleton)
To facilitate movement of the skeleton

Question 4

What determines the function of a joint

Answer 4

A joints structure (anatomy)
The function (action) and range of motion of each joint is dependent upon its anatomy

Question 5

Stability vs Mobility

Answer 5

The most mobile joints are the most unstable
The most stable joints are immovable

Question 6

Which joint is the most mobile/most unstable

Answer 6

Shoulder (easy to dislocate)

Question 7

Which joint is the most stable/immovable

Answer 7

Suture of skull

Question 8

Classification of joints

Answer 8

1. Function - based on range of motion permitted
2. Structure - what tissues joins the articulating bones

Question 9

3 classifications of joints based on range of motion they permit

Answer 9

Synarthrosis - no movement
Amphiarthrosis - little movement
Diarthrosis - wide range of motion

Question 10

4 types of tissues that join articulating bones

Answer 10

Fibrous
Cartilaginous
Bony Fusion
Synovial

Question 11

Which tissues go with synarthroses joints

Answer 11

Fibrous
Cartilaginous
Bony Fusion

Question 12

Features of synarthroses joints

Answer 12

Immobile or nearly immobile
Strong union between articulating bones
Fibrous, cartilaginous, or bony fusion

Question 13

What is fibrous synarthrosis

Answer 13

Suture
Skull bones joined by dense fibrous CT
Immovable (adults); slightly moveable (infants & children)

Question 14

What is bony fusion (synostosis)

Answer 14

Created when bones fuse together
The boundaries separating the bones disappear upon fusion
Ex. pelvic bones; sacrum

Question 15

Fusion of the pelvic bones

Answer 15

Ilium, ischium and pubis fuse to form the pelvic bones
Can’t really tell that they are fused

Question 16

Which tissues go with amphiarthrosis joints

Answer 16

Fibrous and cartilaginous

Question 17

Features of amphiarthroses joints

Answer 17

Permit more movement than a synarthrosis
Articulating bones are joined by fibrous CT or cartilage

Question 18

What is cartilaginous amphiarthrosis

Answer 18

Symphysis - bones are joined by a wedge of cartilage
Allows for slight movement between articulating bones

Question 19

Examples of cartilaginous amphiarthrosis

Answer 19

Intervertebral discs
Pubic symphysis

Question 20

Which tissue goes with diarthrosis joints

Answer 20

Synovial (lots of features to them)

Question 21

Features of synovial joints

Answer 21

Specialized for movement
Permit a wider range of motion than other joint types

Question 22

Where are synovial joints typically found

Answer 22

At the ends of long bones, such as those of the upper and lower limbs

Question 23

What 5 basic components do all synovial joints have

Answer 23

Joint capsule
Articular cartilage
Joint filled cavity synovial fluid
Synovial membrane
Accessory structures

Question 24

What is the joint capsule of a synovial joint made of and what does it do

Answer 24

Outer dense CT layer
Inner synovial membrane
Surrounds synovial joint, encloses joint cavity

Question 25

What is the synovial membrane of a synovial joint

Answer 25

Lines inner surfaces of the joint (does not cover the articulating bone surfaces)

Question 26

What is the joint cavity of a synovial joint

Answer 26

Space where bones are joining with each other

Question 27

Where does the synovial membrane not extend to

Answer 27

The surfaces of the bones

Question 28

What does synovial membrane produce

Answer 28

Synovial fluid

Question 29

What is synovial fluid and what does it do

Answer 29

Clear fluid that fills the joint cavity Lubricates (reduces friction) Absorbs shock Distributes nutrients to cells of the articular cartilage

Question 30

What is the articular cartilage and what does it do

Answer 30

Specialized type of cartilage that covers the surfaces of bones within the joint cavity Smooth surfaces help reduce friction during movement

Question 31

What is arthritis

Answer 31

Deterioration of articular cartilage which causes bone to bone friction

Question 32

What are the accessory structures of synovial joints

Answer 32

Menisci Ligaments Bursae Fat pads Provide support and additional stability

Question 33

What is a menisci and what does it do

Answer 33

C-shaped fibrocartilage pads between bone Reduces friction, disperse weight, protects and cushions joint surfaces Ex. sits between femur and tibia

Question 34

What are ligaments and what do they do

Answer 34

Fibrous CT connecting BONE to BONE Support and strengthen synovial joints

Question 35

Where can ligaments be located

Answer 35

Relative to the joint capsule, can be located: Outside articular capsule (extracapsular) Inside articular capsule (intracapsular)

Question 36

Examples of extracapsular and intracapsular ligaments

Answer 36

Extracapsular - patellar ligament Intracapsular - cruciate ligaments of the knee

Question 37

What is bursae and what does it do

Answer 37

Small fluid-filled pockets in CT, occur around tendons and bones Filled with a synovial fluid, lined by a synovial membrane Reduce friction and act as shock absorbers

Question 38

Example of where bursae is located

Answer 38

On the glenohumeral joint

Question 39

What are fat pads and what do they do

Answer 39

Usually found around the periphery of the joint Protect articular cartilages Cushion joint as a whole