Joints

Question 1

what is a joint

Answer 1

the part of the skeleton where two or more bones meet

Question 2

what are the functions of joints

Answer 2

1. to hold the skeleton together (with the help tendons and ligaments)
2. to give the skeleton mobility

Question 3

what is the difference between tendons and ligaments

Answer 3

1. ligaments attach bone to bone (but still let the joints move)
2. tendons attach muscle to bone
3. ligaments are made up of collagen and elastic fibers (strong, flexible and resilient)
4. while tendons are made up entirely of collagen fibers forming white fibrous tissue (strong and inelastic)
5. Ligaments often form part of the articulate capsule
6. tendons stabilize the joints

Question 4

What do tendons attach to

Answer 4

• stationary bone - the origin
This bone is usually closer to the centre of the body’s axis (such as the scapula)

• movable bone - the insertion
This bone is usually further from the body’s axis (such as the humerus)

Question 5

how to tendons aid in movement

Answer 5

Tendons attach muscles to bones. when a muscle contracts, one bone remains more or less stationary and the other bone is moved, the movable bone moves towards the immovable bone

Question 6

what are the different types of joints classification

Answer 6

• fibrous joints - held together by fibrous tissue and are immovable (eg. sutures of the cranium)
• cartilaginous - held together by cartilage and are partially moveable (eg. joints between vertebrae and the pubic symphysis in the pelvis)
• synovial joints - held together by a double layered articular capsule, have a fluid filled cavity surrounding the bones and are freely movable. (eg. all joints in the limbs, almost all joints in the body)

Question 7

LABEL A DIAGRAM OF A SYNOVIAL JOINY

Answer 7

PAGE 64

Question 8

what are the 4 classifications of synovial joints

Answer 8

• ball and socket joint - allowed lots of movement in all directions (hip and shoulder)
• hinge joint - allows movement up and down but not side to side (knee and elbow)
• pivot joint or axial joint - allows for rotation (atlas and axis)
• plane joint - allows bones to glide over each other (wrist and ankle)

Question 9

what is a bunion

Answer 9

an enlarged bursa usually at the base of the big toe

bursar are flattened sacs filled with synovial fluid that function to reduce friction with the bone

Question 10

what is a sprain

Answer 10

A sprain is the stretching or tearing of ligaments in a joint

strains are graded from 1 to 3

healing is slow due to poor blood supply

most often sprained places are the spine, the ankle, the knee

Question 11

what is a dislocation

Answer 11

a dislocation occurs when bones are forced out of their normal position at joints. often ligaments are torn in the process

Question 12

what is arthritis

Answer 12

a disease that effects joints, and is a term used to cover over 100 different diseases and disorders that make joints painful stiff and swollen

Question 13

name and explain 3 types of arthritis

Answer 13

1. osteoarthritis - the cartilage that cushions the bones in joints softens and wears away, the bones then rub against one another causing pain and stiffness
2. rheumatoid arthritis - a chronic inflammatory disorder where the synovial membrane becomes thickened and inflamed, producing too much synovial fluid and causing the joint to swell, causing it to be painful and deformed. it’s an auto immune disease where the body’s immune system attacks it’s own issues. if allowed to progress the joints may be totally destroyed and the bone ends fuse.
3. gouty arthritis - caused by a build up of uric acid in the blood which results in urate crystals being deposited in the soft tissue of joints. if left untreated the articulating bone ends fuse and immobilize the joint.