Joint structure and function

Question 1

what are the solid joints

Answer 1

• fibrous joint

- cartilaginous joints

Question 2

what are caveatted joints

Answer 2

• synovial joints

Question 3

what are the two divisions of joints

Answer 3

• solid joints

- cavitated joints

Question 4

what joints do not move very much

Answer 4

• solid joints do not move very much therefore this means fibrous and cartilaginous joints do not move very much

Question 5

what skeleton are solid joints mainly in

Answer 5

axial

Question 6

what skeleton are caveatted joints main in

Answer 6

appendicular

Question 7

describe the structure of fibrous joints

Answer 7

• No synovial cavity
• Articulating bones held together by fibrous connective tissue
• Little or no movement

Question 8

name some fibrous joints

Answer 8

• sutures
• synostosis
• syndesmosis
• gomphosis

Question 9

what are sutures

Answer 9

• these are fibrous joints that are between the bones of the skull

Question 10

what is a synostosis

Answer 10

• this is an ossified suture in the skull
• for example we actually have two frontal bones together and they fuse together to form a single frontal bone
• immovable

Question 11

what is a syndemosis

Answer 11

• sheet of fibrous tissue between bones,
• it is the interosseous membrane
• it keeps the radius and the ulnar tethered and stops them separating as you move

Question 12

what is a gomphosis joint

Answer 12

cone-shaped peg fits into a socket

- e.g. teeth this is held by the periodontal ligament

Question 13

what happens in the skull of children

Answer 13

• sutures do not form straight away
• there is a fibrous tissue that connects the frontal bone
• anterior frontanal

Question 14

what is the anterior frontanatal

Answer 14

• present in children
• opening in the skull
• stays open for about 18-24 months,
• then it becomes no longer papltable
• can be used to check intracranial pressure as it causes the anterior frontanatal to bulge

Question 15

describe the structure of the cartilaginous joints

Answer 15

• No synovial cavity
• little or no movement, little more movement then the fibrous joints
• Articulating bones connected by cartilage either fibrous or hyaline cartilage

Question 16

what is the symphysis connected by

Answer 16

fibrocartilage

Question 17

what is the synchrondosis connected by

Answer 17

hyaline cartilage

Question 18

name some cartilaginous joints

Answer 18

• symphysis

- synchrondosis

Question 19

describe what the symphysis is between

Answer 19

• IV discs and pubic symphysis, this means that the pelvis is a bit more flexible at the front

Question 20

describe what synchrondosis is between

Answer 20

• Epiphyseal growth plate and costochondral joints, it is also in the sternal, connects the ribs to the sternum which is hyaline cartilage

Question 21

what can adapt and change

Answer 21

• the fibrocartilage joints is subjected to change

Question 22

describe an example of the fibrocartilage joints adapting and changing

Answer 22

for example women who are about to give birth is that the pubic symphysis softens and becomes more flexible, this helps give a widened pelvic outlook during childbirth and prevents the pelvis from breaking

Question 23

what are the layers of cartilage that surround the IV disc

Answer 23

fibrocartilage

Question 24

describe the structure of synovial joints

Answer 24

• freely movable
• two bones capped with hyaline cartilage
• comes from endochondral ossification and this remains as the hyaline articulating cartilage
• fibrous capsule that acts as a water tight seal
• synovial membrane

Question 25

what does the synovial membrane do

Answer 25

– produces the synovial fluid | - makes sure that the synovial fluid is the correct composition

Question 26

what do the bursa do

Answer 26

- the bursa often interconnect with the joint capsule | - cushions and protections of the joint

Question 27

how are the bursa used in the knee

Answer 27

- The knee has lots of bursa as it has lots of tendons that run from it and over it that need to be protected - The joint capsule extends into the popliteal fossa - Bursa is kept behind the quadriceps helps suspend and keeps bursa from dropping into the knee joint with gravity

Question 28

what type of cartilage is articular cartilage in synovial joints

Answer 28

hyaline cartilage

Question 29

describe the structure of articular cartilage

Answer 29

- Smooth, slippery and very low coefficient of friction - Elastic, resilient structure that acts as a shock absorber to protect underlying bone - Deeper layer merges via a calcified layer with the subchondral bone

Question 30

describe the ECM of articular cartilage

Answer 30

- 80% water - this means that it can act as a shock absorber, when you squeeze the cartilage the water will come out and when you take the pressure off the water is attracted back into the cartilage due to the proteoglycans in the ECM - Collagen type II – this gives it structure - Proteoglycans – this act as the water attracting part of the ECM, and hold it into the cartilage giving gel like ECM

Question 31

what do many synovial joints also contain

Answer 31

- they also contain accessory ligaments and articular discs

Question 32

what do ligaments do

Answer 32

– Ligaments connect bone to bone | • Help to stabilise and hold joint together

Question 33

what do articular discs do

Answer 33

– Articular discs modify shape of joint surfaces | • Help maintain stability of joint, and direct flow of synovial fluid to areas of greatest friction

Question 34

what re the two layers of the articular capsule

Answer 34

- outer fibrous capsule | - inner synovial membrane

Question 35

describe the structure fo the articular cartilage

Answer 35

- avascular therefore it relies on synovial fluid for its nutrition

Question 36

what is the disease that causes the loss of articular cartilage

Answer 36

- Oesoarthritis – degeneration of articular cartilage

Question 37

what are the types of synovial joints

Answer 37

``` plane pivot ball and socket condyloid hinge saddle ```

Question 38

describe the movement and examples of planar joints

Answer 38

- side to side and back and forth gliding movements | - Example, intercarpals, intertarsals, facet joints of vertebral column

Question 39

describe the movement and examples of hinge joints

Answer 39

convex surface of one bone fits into concave surface of another bone. • Flexion and extension in a single plane – Examples, elbow, knee

Question 40

describe the movement and examples of pivot joints

Answer 40

• - round or pointed surface of one bone fits into a ring formed by another bone and a ligament • Rotational movements – Example, atlas rotating about the axis, radius in annular ligament of the ulna

Question 41

describe the movement and examples of condylar joints

Answer 41

• oval shaped condyle of one bone fits into elliptical cavity of another bone • Flexion-extension, abduction-adduction and circumduction – Example, joint between carpals and radius

Question 42

describe the movement and examples of saddle joints

Answer 42

one bone is saddle-shaped, the other is the rider • Flexion-extension, abduction-adduction, and circumduction – Example, carpometacarpal joint of thumb

Question 43

describe the movement and examples of ball and socket joints

Answer 43

• - ball-shaped surface of one bone fits into cup-like depression of other • Flexion-extension, abduction-adduction, rotation and circumduction – Example, shoulder and hip joints