These are linked. A difference in size leads to a difference in shape and performance.

Larger animals: greater gravity significance

Smaller animals: greater significance in surface forces

The study of size and its consquences.

SA≈L²

V ≈L³

Cross Sect Area ≈L²

As size increases, the SA:V decreases.

ex: larger animals have more volume and less SA.

As you get larger, mass increases L³ and CSA increases L²

Form of an object defined by its outline/contour.

when size is changed, shape changes also.

The two parts grow at different rates (one grows slower/faster than the other)

y=ax^b

b=1

Size of the body part increases at the same rate as the body size.

ex: heart size in mammals

b>1

The body part increases in size at a faster rate.

Ex: Skeletal mass

0<b<1

Relative Size of the body part becomes smaller as body size increases.

ex: Relation of SA to body mass.

ex: Head size growth in humans

Size of the body decreases as body mass increases

ex: heart rate in mammals

ex: metabolic rate in mammals

Load.

Weight of body on the joints, pull of muscles, gravity.

Measured at surfaces as stress or pressure.

Compression

Tension

Shear

Torsion

Bones

Notochord

Tendons

Ligaments

Hard, loaded symmetrically.

Greatest stress at the surface (core can be hollow)

Combats: Compression and Tension

Less Combative of: Shear

Fibrous Sheath around fluid-filled center.

Lateral bending and support.

Combats: Compression

Firm, more flexible, and lighter than bone.

Combats: Compression 

Less Combative of: Shear and Tension

Flexible, binding functions (joints), connect muscle to bone (transmits the muscle pull to the bone)

Combats: Tension and Torsion

Less Combative of: Compression

Binding of bone to bone (limits motion at joints).

Functions continuously.

Combats: Tension and Torsion

Less Combative of: Compression

Magnitude of force based on lever size:

Long Lever Arm: speed

Short Lever Arm: force