Joints & Articulations

Question 1

What is an articulation?

Answer 1

• Proper anatomical term name for joint

- place where 2 bones meet and facilitate movement

Question 2

Structural classifications

Answer 2

1. Presence/absence of a synovial cavity

2. type of CT binding the bones together

Question 3

types of joints

Answer 3

• fibrous joints
• cartilaginous joints
• synovial joints

Question 4

Fibrous joints

Answer 4

• no synovial cavity
• bones held together with fibrous CT
• plenty of collagen fibres

ex. sutures between skull bones

Question 5

Cartilaginous joints

Answer 5

• no synovial cavity
• bones held together with cartilage (hyline or fibrocartilage)
• none or slight movement

ex. in hip joint

Question 6

Synovial Joints

Answer 6

presence of synovial cavity ( space)

• bones held together with dense irregular CT
• makes up articular capsule & accessory ligaments
• freely movable
• body’s most numerous and movable joints
• structurally most complex

Question 7

Functional Joint Classification

Answer 7

• degree of movement

1. synarthrosis –> immovable joint
2. Amphiarthrosis –> slightly movable joint
3. Diarthosis –> freely movable joint
   * All diarthroses are also synovial joints structurly

Question 8

Sub-Types of fibrous Joints

Answer 8

1. Sutures
2. Syndesmoses
3. Gomphoses

Question 9

Sutures

Answer 9

• Fuse skull bones together\
• they are synarthrosis sincve no movement occurs
• have irregular edges which increase strength and decrease fracture likelihood

Question 10

Syndesmoses

Answer 10

• Permits slight movement

- classified functionally as an amphiarthroses

Question 11

Gomphoses

Answer 11

• Holds the roots of the teeth
• immovable joint
• classified as a synarthrosis

Question 12

Periodontal Membrane

Answer 12

• ligament that connects tooth root to socket

- breaks down naturally as baby teeth are lost

Question 13

Sub-types of cartilaginous Joints

Answer 13

1. synchondrosis

2. symphysis

Question 14

Synchondrosis

Answer 14

• hyaline cartilage used to connect two bones to one another

ex. epiphyseal plate in epiphyses of long bones

Question 15

Symphysis

Answer 15

• Fibrocartilage is used to connect two bones and absorb shock
• joint is an amphiarthrosis
• all symphyses occur in the midline of the body
• ex. symphysis pubis, intervertebral joints

Question 16

Essential elements of a synovial joint (8)

Answer 16

1. joint capsules
2. joint cavity
3. articular cartilage
4. synovial membrane
5. menisci
6. ligaments
7. bursae
8. tendon sheaths

Question 17

Joint Capsule

Answer 17

formed by extension of periosteum of each articulating bone
- unites bones and encloses synovial cavity

outer layer: frbrous CT (flexible)
-prevents dislocation
Inner layer: synovial membrane

Question 18

Joint Cavity

Answer 18

• space between articulating bones
• filled with synovial fluid which reduces friction by acting as a lubricant
• allows joint to be freely movable

Question 19

Articular Cartilage

Answer 19

• coating of hyaline cartilage on articulating surfaces of each bone in joint
• reduces friction
• joint shock absorber

Question 20

Synovial membrane

Answer 20

• warm up before exercise increases secretion of synovial fluid
• in inner surface of joint capsule
• lines joint cavity
• made of areolar CT with elastic fibres
• can have articular fat pads
• secretes synovial fluid (containing hyaluronic acid & interstitial fluid)
• -> lubricant, brings nutrients, removes wastes
• viscosity of synovial fluid decreases with movement

Question 21

Menisci

Answer 21

• fibrocartilage pad between bones which provides shock absorption
• divide joint cavity into more than one space
• found in knee and temporomandibular joint

Question 22

ligaments

Answer 22

• bundles of dense, white, fibrous CT
• join bones together
• stabilize & strengthen joint
• once overstretched, they wont go back to normal

Question 23

Bursae

Answer 23

• extra pockets or “pads” pf synovial fluid surrounded by a synovial membrane
• not present in all synovial joints
• provide additional cushioning

Question 24

tendon sheaths

Answer 24

• wraps itself around a tendon to reduce friction between tendon and bone
• specialized type of bursa
• not in all synovial joints
• in wrists & ankles

Question 25

Sprain

Answer 25

Partially torn/overstretched ligaments without joint dislocation

Question 26

strain

Answer 26

paritally torn/over stretched muscle

Question 27

types of synovial joints (6)

Answer 27

1. Plantar Joints
2. Hinge Joints
3. Pivot Joints
4. Condyloid Joints
5. Saddle Joints
6. Ball and socket Joints

Question 28

Plantar and Hinge Joints

Answer 28

Plantar: Side to side and back and forth gliding movements (tarsals, carpals)
Hinge: movement around single axis (elbow, knee, ankle)

Question 29

Pivot & condyloid Joints

Answer 29

Pivot: rotational movement around one axi’s (head side to side)

Condyloid: movement around 2 axes (finger up, down & side to side, wrist)

Question 30

Saddle & ball and socket joints

Answer 30

Saddle: movement around 2 axes (thumbs articulation with carpals)
Ball and socket: Movement along multiple axes (shoulder &hip)

Question 31

Mobility occurs as a result of:

Answer 31

1. arrangement of bones
2. location and arrangement of joint ligaments.
3. Location, strength and attachment of joint ligaments
4. Proper functioning of joints

Question 32

Extracapsular ligaments

Answer 32

(outide joint capsule)

-lateral (fibular) and medial (tibular) collateral ligaments

Question 33

Intracapsular Ligaments

Answer 33

(inside joint capsule)

• anterior and posterior cruciate
• attached to tibia
• “lock” the knee