BonesBones

Why Study bones?Why Study bones?

Dr. GrantDr. Grant• You have just found the remains of a

velociraptor in the mountains of Montana.

• After your exciting tropic weekend getaway to Jurassic Park you return to your research only to discover another find.

I’ve got a bone to pick with youI’ve got a bone to pick with you

Putting the pieces togetherPutting the pieces together

• Giant Sloth!!!

UsesUses

X-ray technology

Curiosity

Art?

Biomedical EngineeringBiomedical Engineering

• Replacement Parts– Knees– Hips– Shoulders

In respect to the whole organismIn respect to the whole organism

• While we study the bones here are some things to think about. – Consider how the bones relate to other

systems in the body and how their integration is essential to many organisms, including us.

• Muscular system• Respiratory system• Nervous system• Reproductive system• Circulatory system

JointsJoints

• Where bones do their networking.

• Various types of joints in us.

• Think about why given joint types occurs where they do in the body.– Fibrous (synarthrodial)– Cartilaginous (synchondroses and

sympheses)– Synovial (diarthrosis)

Fibrous Joints Fibrous Joints • This type of joint is held together by only a

ligament.

• Three subclasses– Sutures (join bones of the skull).– Syndesmosis (join long bones together).– Gomphosis (join tooth root to jaw bone).

• Bones in these joints are incapable of movement. – Ex: Teeth in sockets.

Cartilaginous jointsCartilaginous joints• Joined by cartilage, hence the name.

• Two subclasses. – Primary (synchondroses)

• Examples of these joints are the epiphyseal or growth plates at the ends of the long bones. These undergo ossification as we age.

– Secondary (symphyses)• In these joints, the surfaces of the bones to be

joined are each covered with a smooth layer of cartilage

Synovial JointsSynovial Joints• Most common• Five types

– Gliding- – Hinge- – Pivot/Saddle-– Condyloid– Ball and socket

• Allow for the most movement– the presence of lubricating synovial fluid within a

capsule located between the bones is responsible for this feature.

Synovial Joints (cont’d)Synovial Joints (cont’d)

• Gliding Joint– One bone “glides” over another bone.

• Ex: Carpals of the hand, tarsals of the ankle.

Synovial Joints (cont’d)Synovial Joints (cont’d)

• Hinge Joint– Bone surfaces are shaped in such a way that

their movement is only allowed in one directional plane.

• Ex: Elbow, knee.

Synovial Joints (cont’d)Synovial Joints (cont’d)

• Pivot/Saddle Joint– Here movement is also limited but instead to

rotational motion. • Ex: Between the carpals and metacarpals of the

hand.

Synovial Joints (cont’d)Synovial Joints (cont’d)

• Condyloid Joint– Allows for movement such as extension.

• Ex: The wrist joint.

Synovial Joints (cont’d)Synovial Joints (cont’d)

• Ball and Socket Joint– Provides the most movement. The distal

bone is capable of 360 degree rotation. • Ex: Pelvis joint, shoulder joint.

Things to PonderThings to Ponder• As we continue to study bones in depth

here are some things to consider.– Think about the shape of the bone’s ends

relative to joint type, just as doctor’s do in treatment and paleontologists do when attempting to complete a fossil and when biomedical engineers take a joints movement requirements when shaping a replacement part.

– Keep these things in mind during the knee replacement next week and think about the kinds of things the doctors need to know about joints in order to do the operation.