Question | Answer |
What are the 3 types of joints? | 1. fibrous 2. cartilaginous 3. synovial |
what percentage of your joints are synovial joints? | 90% |
what are the characteristics of synovial joints? | highly moveable and they all have synovial capsule surrounding the entire joint (synovial membrane) which secretes synovial fluid and cartilage which pads the ends of the articulating bones. |
what is a synovial capsule? | collagenous structure that surrounds the entire joint |
what is the synovial membrane? | the inner layer of epithelial tissue of the capsule which secretes synovial fluid. there is blood supply here so oxygen gets in indirectly. |
what is hyaline cartilage? | cartilage which pads the ends of the articulating bones |
what are the 3 things synovial joints have? | 1. synovial capsule 2. synovial membrane 2. hyaline cartilage |
what is synovial fluid? | lubricating liquid that has a consistency of snot (thick and slippery). these surfaces move past one another with minimal friction |
what are ligaments? | attachments of bone to bone |
joints that are not moveable are? | 1. cranial joints 2. joints between sacrum and 2 hip bones (sacrohippum joints) 3. teeth |
what are periodontal ligaments? | ligament that holds teeth down. made of collagen |
what happens when you crack your knuckles? | increase volume between the ones so pressure drops caused by pulling nitrogen bubbles out of blood. |
why can't you crack knuckles right after you crack them once? | there is a period of time you need to wait for nitrogen bubbles to go back into solution again |
what are fibrous joints? | joints help together by ligaments. i.e. teeth= periodontal ligaments |
what are articular capsules? | articular capsules surround each synovial joint |
what part of the bone erodes? | cartilage, but this does not have to do with old age |
what are cartilagenous joints? | connection between articulating bones. i.e. vertebrae, chest(sternum) |
3 types of synovial joints are? | 1. hinge joint 2. condyloid joints 3. ball and socket joints |
example of hinge joint | elbow and knee |
what kind of movement does hinge joint have? | flexion/extension |
examples of condyloid joints | wrist/phalanges |
what kind of movement does condyloid joints have? | flexion/extension adduction/abduction circumduction |
examples of ball and socket joints | shoulder and hip |
what kind of movement does ball and socket have? | flexion/extension adduction/abduction internal and external rotation |
how stable are mobile joints? | most mobile joints are least stable |
First Class lever | weight and force are on opposite sides of the fulcrum. muscle on either side of fulcrum. very rare in the body |
examples of first class lever | skull and atlas vertebrae of the spine |
Second Class lever | load is between the fulcrum and the force. weight is on the side of the fulcrum |
examples of second class lever | pushing or pulling across the heel of the foot |
third class lever | force is between the fulcrum and load. used 90% of the time by muscles. |
examples of third class lever | elbow joint.picking up something or fishing |
what happens to the muscles when you do work? | even the long ones shorten about .5-1 inch |
what is the disc? | fiber cartilage. it is flexible but has higher collagen component. it is still, but compressible. it is hard to repair than regular cartilage |
what is a meniscus? | knee disc. makes joints fit together better. keeps them froms liding off by creating a concave place for the heads of bones to fit |
what is a labrum? | shoulder disc. fiber cartilage that runs around glenoid. it makes the surface that the shoulder is sitting in bigger and more concave |
what is TMJ? | jaw disc. can open jaw and then open it even further. you can feel it drop and swing forward. |
articular disc allow for jaw to? | open further, drop, and swing forward |
what happens when someone has TMJ? | usually from chewing gum. basically occurs when there is a loose disc in the fossa. it sits into position and snaps back. |
do discs wear out? | yes! as you get older, discs wear out |
what areas of your body have the most stress? | knees, hips, and shoulders |
how many ligaments to most important joints have? | about half a dozen |
what is bursa? | fluid-filled sac, lined with synovial membranes, that occurs near a joint. allows the skin to move around. |
what is bursitis? | inflammation of bursa. if the bursa become inflammed then it fills up with fluid. |
what is articular cartilage? | aka hyaline cartilage that has its surface moving past each other. there no is no blood supply nor nerve supply. important in movement of one bone against another. |