Body identify its own tissue that isn't in blood flow?

I thought scar tissue was highly vascularized - I'd double check that statement!

Further, you mentioned the lens; the fact that it is transparent definitely means it is avascular. However, that does not mean it has "immune privilege". Immune privilege is the idea that there are certain regions, the nervous system, cornea, retina, anterior chamber of the eye, testis, and liver for example, in which immune surveillance is reduced. Instead, according to the attached article, it should be considered immune quiescence instead (a state of low baseline immune activation).

Let's assume your original assumption is true, that the lens has this "immune privilege". You're wondering what allows certain tissue to have lower security, for example. The theory of immune privilege is based on the idea that there is:

1) anatomic separation between blood and neural tissue (in the case of the lens),
2) molecules required for antigen presentation are absent under normal physiological conditions (which is what I was originally thinking),
3) absence of lymph drainage, and
4) decreased T-cell surveillance.

Those are the four reasons why some tissue are more "privileged" than others. Interesting, the idea originated in 1948 when observations that homologous skin transplantations into the brain did not elicit the same degree of immune response as transplantations into other sites [1].

"Because scar tissue does not have blood flow, cold is spreading as fast or faster through the scar tissue than the normal myocardium"

I found this at sciencedirect.com.

Don't know if that is heart specific?

According to this article:


Below, I have highlighted some more key parts in the article that say it much better than I do:

Do you know of other tissues that get no blood flow other than eye lens and vitreous gel?

And do you think we get cataracts because there is zero blood flow in the lens? I know images might appear more red, but with blood flow might proteins accumulating on the lens have a means to clean up?

Cartilage! That's why once cartilage is damaged, it does not get repaired as easily as other tissues might. It has repair mechanisms in place, but repair is typically slow and ineffective. Cataract forms when protein deposits build up on the lens of the eye. For example, a perforating wound to the capsule of the lens will cause leakage into their area, leading to opaque lens characteristic of cataracts. Thus, you could say that because it is NOT vascularized, there's really no mechanism to clean up the build up of proteins, or whatever is built up there.