Do certain cells do better than others?

[icakeov]

I was wondering about the discrepancies between how well individuals cells "perform" within a multicellular organism.

For example, all the muscle cells in my right arm, are they all being coded to be "exactly the same", or at least more or less the same based on where they land? But will each of these cells be different in size, performance, etc.

And would me exercising my muscles put different "strains" on certain cells, making some cells not being able to "keep up"?

Furthermore, as cells get recycled and new ones take their place, would the new cells sometimes do better or worse than their predecessors? (I gather age can play a part in them gradually doing worse?)

By "perform", I mean for example: how developed (large, small, effective) their cell components are compared to other cells, how many essential proteins they create compared to the cells around them, or how many mitochondria they have (I've seen this varies in cells), etc.

Hope that was clear enough.
Comments and suggestions appreciated!

 

[BillTre]

There are many kinds of muscle cells, some of which are probably not what you are interested in, but here's an overview:

Smooth muscle (also called involuntary); this is non-striated (the molecular contractile mechanism is not aligned and therefore not apparent in the microscope). This is involved in things like blood vessels and organs. innervated by autonomic nervous system.

Cardiac muscle is in the heart, autonomically innervated, striated, pumps blood. In some animals it can beat without innervation, some animals require innervation for it to beat. Does not tire easily (thank goodness).

Pharyngeal muscle: looks like skeletal striated muscle, but with an embryologically different origin. Innervated by a slightly different set of motor neurons. Has many specializations like the muscle of the little bones in the inner ear. In some bats these can contract extremely rapidly so the ear bones can decouple the vibrations of the eardrum from the cochlea (where the sensory hair cells are) to protect the hairs cells from damage from the bat's own sonar pulses.

Skeletal muscle: This is the kind of muscle most people think about. Innervated by motor neurons under "conscious control".
There are sub-types of these muscle fibers, including slow and fast twitch fibers.
Slow contract more slowly, but can sustain activeity for longer periods of time (more mitochondria and vascularization). Fast is the opposite.
Alberto Salazar is a former marathoner who is supposed to have an unusual amount of slow twitch fibers which helped him keep going in his marathoning.

Clearly these are all specialized for their purposes int he body and there are significant difference between fast and slow fibers.

I don't know a lot about human muscles, but in animals there can be significant specializations among different muscle in an animal's body, depending upon the use they were selected (by evolution) for. A list of these differences would be huge.

The shape of muscles will affect their function because the force of the fibers contraction will affect skeletal movement differently.

 

[icakeov]

Thanks BillTre!

I am curious about the last part of your answer, that is, differences between same types of muscles (muscles as one example of any types of cells).

I think another way of asking this question is: when a cell splits whether daughter cells are identical to the parent? The answer is got to be no "no" to this one (with a simple google search :) ).

I was wondering how that difference manifests itself within all the different cell components and surrounding cells? Would one cell for example be able to produce more proteins because it ended up with more "protein synthesis" molecules? And as a result "do better" or be more effective and how "well it would do" in the organism?

 

[icakeov]

Additionally, are there differently distributed alleles coding for slightly different proteins in different cells, making same-type-cells behave slightly differently, despite being "genetically equivalent"? Or alleles usually consistent in cells throughout an organism?

 

[jim mcnamara]

Cell differentiation - the concept you are getting at - is under environmental control. Location of a cell and it neighbor cells tell the cell which genes to turn off/on, for example. Rather than me blather, this video explains everything you are asking. And a lot more that you may find interesting. Pay attention to the crocodile comments.



PS: epigenetics is key here.

 

[icakeov]

Great thanks Jim! The thread really helped turn me in the correct direction.