Anatomy & Physiology B/C

[varunscs11]

Just curious, but do you memorize every Wiki page on Anatomy out there?

pigeon no. I just dump it on the cheat sheet. Architectural gear ratio, Stratum malpighii, Virchow's law, and many other obscure crap should not waste brain space.

I'm just rubbing off on him. Thats what I basically do for green gen also.

[watermydoing14]

What is a costamere? What is its role in a muscle cell and how is it important in relation to muscular dystrophies?

Gratz for stumping me, Wiki'd this (Click to Show Hidden Text)

Thanks for introducing me to Histology: muscle tissue on Wikipedia. And I thought I read every page there was. Costamere connects the sarcomere to the cell membrane, aligned with Z-Disc under the sarcomere. I assume because lack of dystrophin results in muscular dystrophy, the Dystrophin-Glycoprotein Complex in the costamere is disrupted, leading to instability and degeneration.

Correct! Your turn

[Uber]

Describe in GREAT detail excitation-contraction coupling.
Include DHPR specifics, RYR, calsequestrin, troponin subunits T,I,C, and tropomyosin

[sciolyFTW_aku]

Describe in GREAT detail excitation-contraction coupling.
Include DHPR specifics, RYR, calsequestrin, troponin subunits T,I,C, and tropomyosin

I have a feeling this one won't be answered in a while...

[Uber]

I have a feeling this one won't be answered in a while...

Start learnin' >:O

[sciolyFTW_aku]

Tbh, I don't think they'll even ask you to explain in great detail at the national level too...

[Uber]

Tbh, I don't think they'll even ask you to explain in great detail at the national level too...

D:
Then have fun learning about physiology (This is what Scio is right? )

[watermydoing14]

Describe in GREAT detail excitation-contraction coupling.
Include DHPR specifics, RYR, calsequestrin, troponin subunits T,I,C, and tropomyosin

I promise I will try to answer this but I don't have time right now to figure it out (

[sciolyFTW_aku]

Tbh, I don't think they'll even ask you to explain in great detail at the national level too...

D:
Then have fun learning about physiology (This is what Scio is right? )

Fun???

Anyways, here's all you need to know about excitation-contraction coupling. So kids, start taking notes

Answer (Click to Show Hidden Text)

Excitation-contraction coupling is the process in which a motor neuron conducts action potentials that travel to hundreds of skeletal fibers within muscles. In skeletal muscles, the coupling relies on two key proteins: the SR calcium release channel (the ryanodine receptor, RyR), and voltage-gated L-type channels (dihydropyridine receptors, DHPRs). This process occurs in the triad: a transverse tubule and two SR regions, which contain RyRs. These are the steps:

1) membrane potential of muscle cell depolarized by action potential
2) depolarization activates DHPRs
3) activates RyR (type 1) 
4) as RyRs open, Ca (calcium) is released from SR in local space, which diffuses into cytoplasm. This causes a "cytoplasm spark".
5) The activation of 1000s of Ca spark at nearly the same time causes cell-wide increase in calcium, givs rise to upstroke of Ca transient
6) calcium released into cytosol binds to Troponin C (troponin has 3 subunits: T, I, C) by actin filaments, allowing cross-bridge cycling (last phase in muscular contraction)
7) the SERCA pumps Ca back into SR
8) as Ca declines to resting levels, relaxation occurs

source: https://en.wikipedia.org/wiki/Muscle_contraction#Excitation-contraction_coupling_in_skeletal_muscles

[radioactiveviolet]

Kudos to the explanation from sciolyFTW_aku, and I hope this one's a bit easier

Question (Click to Show Hidden Text)

A woman comes into the E.R. with severe burns in the epidermis and extending into the dermis, characterized by swelling and blistering of the skin that was burned.  The anterior side of her left leg and left arm were affected. (a) What degree burns does this woman have? (b) What percentage of her body is burnt?