HBS 4.1-4.2
How do bones, muscles and joints work together to move the body?
Muscles get the electrical signals to move and then induce the movement of tendons which pull on the bones and move them at the joints.
What is the function of cartilage?
Provides support and some flexibility and movement not as strong as bone; less rigid than bone but has more stability than muscle; facilitates smooth movements at joints
What does ROM study?
Range of motion assess joint motion and provide a measure of overall flexibility
What is the structure of cartilage?
Rubbery ground substance
How can an individual improve their range of motion at a particular joint?
Stretch and strengthen surrounding muscles daily
Example of a fibrous joint
Sutures in the skull, connect the bones that shield the brain
Without joints what would happen?
We would be unable to bend and flex
What is active movement?
When the person moves their own limb through the desired motion to the natural endpoint, shows the subject's ROM
What is passive movement?
When the person's limb is taken through the desired ROM, provides an estimate of ROM and demonstrates the desired motion
Describe condyloid joints
-egg shaped articular surface of one bone fits into an oval concavity in another -allow the moving of bone to travel side to side and back and forth but cannot rotate -biaxial -knuckles (metacarpals and phalanges), ankle, wrist
Describe pivot joints
-rounded end of one bone fits into a sleeve or ring of bone (or ligament) -rotating bone turns around its long axis -uniaxial -ulna and radius
Describe ball and socket joints
-spherical head of one bone fits into a round socket in another -allow movement in all axes including rotation, most free moving joint -multiaxial -shoulder (humerus and scapula), hip (pelvis and femur)
Describe Synovial joints
-articular (hyaline) cartilage covers the ends of the bones forming the joints -the joint surfaces are enclosed by a sleeve or capsule of fibrous connective tissue and the capsule is lined with a smooth synovial membrane -the articular capsule encloses a cavity called the joint cavity, which contains lubricating synovial fluid
Describe plane/gliding joints
-articular surfaces are essentially flat -only allow short slipping or sliding movements -nonaxial -intercarpals (midhand)
Describe hinge joints
-cylindrical end of one bone fits into a trough-shaped surface on another -angular movement in one plane -uniaxial -elbow (ulna and humerus), knee (tibia and femur)
Describe saddle joints
-each articular surface has both convex and concave areas -allow the moving of bone to travel side to side and back and forth but cannot rotate -biaxial -carpometacarpal (thumb)
What is the structure of ligaments?
A band of dense connective tissue with lines running down it, very stiff, shorter, less flexible
What is a goniometer?
A device that measures angles resulting from the movement of various joints
What are the three structural classifications of joints? Why?
Fibrous, cartilaginous, synovial; if there is fibrous tissue, cartilage, or a fluid filled cavity separating the bony ends of the joint
Which type of joint allows for the greatest number of different movements? Explain your reasoning.
Ball and Socket joints allow for the greatest number of different movements because they are multiaxial and can move along all axes and can rotate.
How are joints classifies by function?
By how much movement they allow
How can joints be classified?
By structure or function
What is the function of ligaments?
Connects bones to other bones to form joints
Flexion
Movement that decreases the angle of the joint and brings the bones closer together, bending elbow/knee
Extension
Movement that increases the angle of the joint and takes the bones further apart, straightening elbow/knee
Plantal Flexion
Depression the foot, pointing the toes
Circumduction
Movement where the proximal end is stationary and the distal end moves in a circle, arm circles
Hyperextension
Extension past 180*, my elbows
Abduction
Moving a limb away from the midline, raising arms sideways
What does it mean to have a dislocated shoulder?
If you have a dislocated shoulder then the proximal end of the humerus, which is shaped like a ball comes out of the socket shape of the scapula.
You overhear two women at the gym talking about their extensor muscles of the forearm. Based on what you know about the movement at joints, how would you describe the movement of these muscles?
Increasing the angle of the elbow
What factors influence range of motion of a joint?
Injury, flexibility of muscles, sports, age, activity level
Your favorite team is winning the championship game. You drop to one knee, tip your head back, raise one hand over your head, clench your fist and yell, "Yes." Use the proper terms to describe the movements undertaken by your joints.
Knee flexion, hip flexion, plantar flexion; cervical vertebrae hyperextension; shoulder abduction; metacarpal flexion; mandible depression
Dorsiflexion
Lifting the foot so the superior surface approaches the shin, flexing foot
Where are freely moveable joints and what is their function?
Mainly on the appendicular skeleton, permit flexibility in the limbs and provide a greater degree of motion
Where are immovable and slightly moveable joints and what is their function?
Mainly on the axial skeleton, protection and stability
What is the function of synovial fluid?
Makes joints easier to move back and forth
What are the regions of a cross section of bone, starting from the inside?
Marrow, spongy/cancellous tissue, compact/cortical tissue, periosteum
Rotation
Movement around a longitudinal axis, turning out leg
Depression
Movement in an inferior direction, opening jaw
Adduction
Moving a limb towards the midline, lowering arms sideways
How are tendons and ligaments similar in both structure and function? How are they different in both structure and function?
Tendons and ligaments are similar in structure and function because they are both strong bands of fibers that hold parts of the body together to induce movement. They are different because tendons connect muscles to bones and ligaments connect muscles to muscles. Ligament fibers are crisscrossed and tendon fibers are parallel and twisting. Ligaments are shorter and tendons are longers
What do all body movements require?
The coordinated action of our muscles and our bones
What type of joint is the hip joint? What type(s) of movement can this joint carry out?
The hip joint is a ball and socket joint. It can move in all axes including rotation.
What is the only bone in the body that doesn't meet up with any other bone?
The hyoid bone in the throat
Example of a cartilaginous joint
The pubic symphysis, the piece of cartilage at the bottom of the pelvic bone
What does double jointed mean?
There are NOT two joints, but the one is unusually flexible
What is the function of tendons?
To join muscle to bone and are capable of resisting high tensile forces while transmitting forces from muscle to bone
What is the structure of tendons?
Tough band that is able to withstand a lot of tension, longer, more flexible
What is the texture of articular cartilage?
Very smooth and slimy
Why did we observe the elbow joint of a cow? Why is a cow elbow different structurally from your elbow?
We observed the elbow of the cow because it is anatomically similar to our elbows. It is different because the ulna and radius of a cow elbow are fused together and ours are not.
Elevation
movement in a superior direction, shrugging shoulders