Cell Biology

Question 1

Tendon major components

Answer 1

fibroblasts, Extracellular matrix, ground substance, type I collagen (more rigid than flexible to relay movement to bone)

Question 2

Fibroblast components

Answer 2

Microtubules (attach to connectors and they attach to cell membrane), microfilaments (attach to edge of cell and to intermediate filaments to nucleus),

Question 3

Fibroblast function

Answer 3

produce components of the ECM including fibers like collagen and elastin and ground proteins

Question 4

ECM function

Answer 4

determines mechanical properties of the tissue

Question 5

Cytoskeleton function

Answer 5

critical for cell shape/structure and function

Question 6

Extracellular part of tissue cell

Answer 6

ECM is the structure of the interstitial space

Question 7

Mechanotransduction definition

Answer 7

transduction of mechanical stimuli into cellular signal and response

Question 8

How do cells receive signals from mechanical stimuli into ECM production?

Answer 8

Collagen fibers in ECM attach to membrane-bound proteins (integrins), that are attached to the cytoskeleton and ECM and allow transmission of info

Question 9

Stretch activated ion channels

Answer 9

When the membrane is deformed, ion channels sense it and change their permeability

Question 10

Signal transduction?

Answer 10

The signal cascades to the nucleus and activates gene coding for collagen, collagen is eventually excreted and cell responds by up regulating protein production/remodeling of tendons

Question 11

Define Physical Stress Theory

Answer 11

Changes in relative level of physical stress can cause a predictable response in all biological tissue

Question 12

5 Characteristic Responses to Stress

Answer 12

Increased stress = increased tolerance to stress (hypertrophy), injury, tissue death
Maintenance
Decreased stress = decreased tolerance to stress (atrophy), tissue death

Question 13

What do the thresholds of the physical stress theory show us?

Answer 13

boundaries for effective dose

Question 14

What are stress levels comprised of?

Answer 14

magnitude, time and direction

Question 15

tendon primary function

Answer 15

relay the movement of muscle to bone

Question 16

process of ECM synthesis or degradation

Answer 16

Mechanical stimulus > tissue mechanical properties influence tissue forces > cellular forces are influenced by cell mechanical properties and cause cytoskeletal rearrangement > causes a molecular response > ECM synthesis or degradation