topic 8 + 9 musculoskeletal system Flashcards
define joint
the site at which 2 or more bones come together
some are rigid, some allow for lots of movement
types of joints
- fibrous or fixed joints
- cartilaginous or slightly moveable joints
- synovial or free moveable joints
define fibrous joints
no movement occurs between bones
bones held in place by fibrous connective tissue
very difficult to damage- more likely to fracture bone before the joint will give way
eg. skull, teeth, jaw
define cartilaginous joints
bones are held in place by fibrocartilage- which allows for slight movement to occur
eg. between ribs and sternum
define Synovial joints
amount of movement is limited by ligaments, muscles, tendons and adjoining bones.
eg. shoulder, elbow, knee
this type of joint is most easily damaged because of high degree of movement that can occur
-ligaments, tendons and muscle can be torn.
what are the 6 types of Synovial Joints
ball and socket
hinge joints
pivot joints
gliding joints
saddle joints
condyloid joint
define ball and socket
one bone= spherical head
other bone= cup like cavity
rotational- almost 360 degree movement
femur/pelvic joints
define hinge joints
one bone= convex
other=concave
movement is one plane- like opening a door
eg elbow and knee
define pivot joints
twisting movement
one bone= pointed end
other bone= forms part of a ring
eg neck (1st and 2nd vertebra)
define gliding joints
movement is in any direction
-side to side
-back and forth
-restricted only by ligaments or bony process that surround joint
eg. between scapula and clavicle
define saddle joint
eg thumb and hand
both bones= saddle shaped
fit together to allow side-side and back-forth movement
define condyloid joint
one bone slightly convex
other slightly concave
but both are almost flat
movement side-side and back forth
why are freely moving joints called synovial joints?
because they have a space (synovial cavity) between the articulating surfaces which essentially lubricates the joint so it moves smoothly
parts of synovial joints:
Articular Capsule
surrounds and encloses the joint. the capsule is composed of 2 layers. (fibrous capsule and synovial membrane)
fibrous capsule
principle structure for holding bones together
- dense fibrous CT, attached to each bone
- flexible to permit movement, strong to prevent dislocation