Cell Mechanobiology (9/3b) Flashcards Preview

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Flashcards in Cell Mechanobiology (9/3b) Deck (33)
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1
Q

Connective tissue (CT)

A

made up of cells and extracellular matrix

2
Q

Tendon

A

type of connective tissue

conveys the tension created by muscles onto the bones, and also provide support

3
Q

Fibroblasts

A

cells in a tendon that separate the components of extracellular matrix

4
Q

Extracellular Matrix (ECM)

A

made up of ground substance and fibers

5
Q

Ground substance (ECM)

A

Proteins: Proteoglycans and glycosaminoglycans - strongly hydrophilic, attract water

Glycoproteins link ECM components

6
Q

Fibers (ECM)

A

Collagen (primarily type 1), elastin

In tendon, collagen bundles arranged in parallel to resist tension

7
Q

Fibroblast structure

A

Cytoskeleton provides structure and aids in mechanotransduction

Microtubules (MTs), Intermediate Filaments (IFs), Microfilaments (MFs)

Desmosomal cadherins and integrins

Continuous chain of communication (EX: gap junctions) from outside of the cell to nucleus

8
Q

Gap junction

A

specialized intercellular connection between the cytoplasms of two cells, allowing messages to be relayed

9
Q

Microtubules (MTs)

A

polymers of tubulin that form part of the cytoskeleton

provide structure and shape to the cytoplasm

10
Q

Intermediate Filaments (IFs)

A

provide mechanical support for the plasma membrane where it comes into contact with other cells or with the extracellular matrix

do not participate in cell motility

11
Q

Microfilaments (MFs)

A

mostly composed of actin, also called actin filaments

the smallest filaments of the cytoskeleton. aids in cell movement, muscle contraction, cell division

12
Q

Cadherins

A

calcium-dependent cell adhesion molecules that play a role in cell-cell adhesion and maintaining integrity of multicellular structures

a main component of zonula adherens

13
Q

Integrins

A

transmembrane receptors that facilitate cell-extracellular matrix adhesion

14
Q

Mechanotransduction

A

transduction of mechanical stimuli into a cellular signal and a response

mechanical stimulus>tissue forces>cellular forces>molecular response

15
Q

Types of Forces (Forces)

A
Tension
Shear
Vibration
Compression
Hydrostatic Pressure
Fluid Shear
16
Q

Tension (Forces)

A

force pulling away from point

17
Q

Shear (Forces)

A

unaligned forces pushing one part of a body one way and another part of the body an opposite way

18
Q

Vibration (Forces)

A

forces moving quickly and repeatedly around an equilibrium point

19
Q

Compression (Forces)

A

force pushing down on point

20
Q

Hydrostatic Pressure (Forces)

A

pressure exerted by a fluid at equilibrium at a given point within the fluid, due to gravity force

21
Q

Fluid Shear (Forces)

A

shear stress developed due to particles in fluid moving relative to one another

22
Q

How are mechanical stimuli sensed

A

Collagen fibers in ECM linked to cytoskeleton via integrin proteins

Stretch-activated ion channels

G-protein coupled receptors

Growth-factor receptors

Integrins

23
Q

Signal Transduction

A

by direct structural links between cytoskeleton and nucleus, and intracellular signaling cascades

24
Q

Physical Stress Theory (PST)

A

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

25
Q

Physical stress (PST)

A

force applied to an area of tissue

Force = mass * acceleration

Stress = force/area of tissue

26
Q

5 Characteristic Responses to Stress

A
Death
Decreased tolerance
Maintenance
Increased tolerance
Injury
27
Q

Stress level is a composite of these 3 things

A

Magnitude
Time
Direction

28
Q

Excessive stress can be

A

1) high magnitude brief duration
2) low magnitude long duration
3) moderate magnitude many times

29
Q

What can increase thresholds for stress

A

Overload

Progression of exercise stimulus

30
Q

What can decrease thresholds for stress

A

inflammation

prolonged low stress

31
Q

RICE (Inflammation)

A

Rest, Ice, Compression, Elevation

32
Q

PRICE (Inflammation)

A

Protection, Rest, Ice, Compression, Elevation

33
Q

POLICE (Inflammation)

A

Protection, Optimum Loading, Ice, Compression, Elevation