opp exam 1

A phenomenon in which components join together to form larger, stable structures.

Develops through an incredibly complex series of interactions

Made up of components or subsystems that have their own behavioral properties

• Once assembled, they have new properties that could not have been predicted based
• upon the characteristics of their individual parts.

Spirals

Triangulated Forms

Tetragons

Pentagons

Hexagons

• Refers to a system that stabilizes itself mechanically because of the opposing forces
• of tension and compression and they way they are balanced and distributed
• within the structure.

Compression bearing rigid struts

Stretch or tense the Tension Bearing Elements

Continuous with the Compressible Elements

Adds tension and compression to the Discontinuous Compressible Elements

**adds tension to structure; structure wont change without prestress

• Concept whereby a structure is placed in a balance between tension and compression
• before an external force is involved.

Interaction between the tension bearing and compression bearing elements.

Rigid struts stretch or oppose the tension bearing elements.

Tension bearing elements add compressive force to the rigid struts.

Tension is continuously transmitted across all members of the structure.

• As such, change in one component (compressive or tensile) changes tension in all
• structures regardless of their location in the structure.

• Due to this interaction, the tensegrity structure repositions itself or changes
• conformation to best withstand stress and offer the maximal amount of strength
• for a given amount of building material.

Bones = (discontinuous compressible elements)

Muscles, ligaments, tendons, and fascia = (tension bearing elements)

Proteins stabilize through tensegrity via hydrogen bonds and structural conformations

• Receptors activate in a similar manner when they come in contact with drugs, hormones,
• neurotransmitters, etc.

• We now know that integrins or adhesion receptors bind the cells to the substrate and due to the concept of
• tensegrity, cause the changes seen in the substrate.

• Cytoskeleton is a network of contractile microfilaments which creates a tensegrity network
• within the cell.

• This network holds and suspends the contents of the cell (organelles, nucleus, cell
• membrane, etc.) and pulls towards the cell’s nucleus (Tension Bearing
• Elements).

Internal Compression Bearing Elements:

Microtubules

Large bundles of cross-linked microfilaments

External opposition is created by the extracellular matrix.

Andrew Matus created cells that produced fluorescent microtubules.

Has observed these tubules buckling under cellular compression.

• Suggests that the structure of the cell’s cytoskeleton can be changed by altering the
• balance of physical forces transmitted across the cell surface.

• Important because many of the enzymes and other substances that control protein
• synthesis, energy conversion, and cellular growth are physically immobilized on
• the cytoskeleton.

• Changes in cytoskeletal geometry and mechanics could affect biochemical reactions, alter the genes that
• are activated and thus the proteins that are made.

Flattened cells became more likely to undergo mitosis

Rounded cells underwent apoptosis

Somewhere in between resulted in differentiation and neither divided nor died.

Capillary cells formed hollow capillary tubes

Hepatic cells secreted proteins

Flattened cells became more likely to undergo mitosis

ÒRounded cells underwent apoptosis

Somewhere in between resulted in differentiation and neither divided nor died.

Capillary cells formed hollow capillary tubes

Hepatic cells secreted proteins

bones, cell membranes, organelles

muscle, ligaments, fascia, cytoskeleton, DNA?

• In vitro Repetitive Motion Strain (RMS) model has a different effect on
• fibroblasts than IMFR.

• RMS appears to reduce fibroblast proliferation and creates a delayed inflammatory
• response.

IMFR does not cause a reduction in fibroblast proliferation and:

Reverses inflammatory effects on repetitively strained cells

Causes fibroblast proliferation

• Causes expression/secretion of proinflammatory
• and anti-inflammatory interleukins