1. 11.2 Muscles and Movement

3. The joints in our body provide mobility and hold the body together
The joints in our body provide mobility and hold the body together. Most joints include the following:
Bones
Ligaments
Muscles
Tendons
Nerves
Interesting Note:
Arthrology is the study of joints and Rheumatology is the branch of medicine devoted to joint diseases/conditions

4. Their Function in Movement
1. Bones – they contain several different tissues and are therefore considered organs
They provide a hard framework to support the body
They allow protection of vulnerable softer tissue and organs
They acts as levers so movement can occur
They form blood cells in their bone marrow
They allow the storage of minerals (esp. Calcium and Phosphorus)

5. Bones involved in Movement
Human adults have 206 bones

6. 2. Muscles – for movement to occur muscles must be attached to bones and this attachment is provided by the tendons
Muscles provide the force necessary for movement by shortening the length of their fibers (this is why muscles must exist as antagonistic pairs )

7. Ex: hamstring contracts to bend knee and quadriceps contracts to straighten knee

8. 3. Tendons – cords of dense connective tissue

9. 4. Ligaments – tough band-like structures that serve to strengthen the joint by connecting bone to bone; ligaments have many different types of sensory nerve endings that constantly monitor the joint to ensure no hyperextension
KNEE JOINT

11. Human Elbow Joint
Draw fully labeled joint on board

12. Elbow Parts and their Function
Joint Part
Function
Cartilage
Reduces friction and absorbs compression
Synovial fluid
Lubricates to reduce friction and provides nutrients to the cells of the cartilage
Joint capsule
Surrounds the joint, encloses the synovial cavity, and unites the connecting bones
Tendons
Attach muscle to bone
Ligaments
Connect bone to bone
Biceps muscle
Contracts to bring about flexion (bending) of arm
Triceps muscle
Contracts to cause extension (straightening) of arm
Humerus
Upper arm bone; Acts as a lever that allows anchorage of the muscles to the elbow
Radius
Lower, top arm bone; acts as a lever for biceps
Ulna
Lower, bottom arm bone; acts as a lever for triceps

13. Hinge Joints
The elbow and the knee are both hinge joints since they permit an opening/closing type of movement
Both are also one directional
Both also are called synovial joints because they have a synovial cavity

15. Ball and Socket Joints
Examples include the hip joint and shoulder joint
Permits movement in several directions

16. Ball and Socket vs. Hinge Joints
Hip Joint
Knee Joint
Freely movable
Angular motions in many directions and rotational movements
Angular motion in one direction
Motions possible are flexion, extension, abduction, adduction, circumduction, and rotation
Motions possible are flexion and extension
Ball-like structure fits into a cup-like depression
Convex surface fits into a concave surface

17. Definitions of Movement
Flexion – decrease in angle between connecting bones
Extension – increase in angle between connecting bone
Abduction – movement of bone away from body midline
Adduction – movement of bone toward midline
Circumduction – distal or far end of a limb moves in a circle
Rotation – a bone revolves around it own axis