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