Diabetic retinopathy Endocrine system diseases NCLEXRN Khan Academy
Did you know that diabetes is the most common cause of blindness in individuals from the ages of 25 to 65? And blindness can be caused by multiple different complications associated with diabetes including glaucoma and cataracts, however in this tutorial, let’s discuss the most common cause of blindness due to diabetes which is a condition known as diabetic retinopathy.
And if we break down the term, we can receive generally, an understanding of what this disease is, so you have retino here meaning the retina, and pathy meaning disease. So, diabetic retinopathy is a disease of the retina that’s caused by diabetes. And to describe what the retina is, let’s bring in a diagram of the eye.
And go through some of the structures as it will help us as we learn more about this condition. Over here on the left, we have a crosssection of the eye and there’s a few important structures to note. So this is the front of the eye here, and this is the back of the eye, and this part right here is known as the cornea. And it is where light initially passes through.
As it goes through the eye, and then it hits this structure right here, which is known as the lens. And the lens focuses the light on this structure in the back of the eye, this kind of brownish structure, and this is the retina. And then exiting the back of the eye here, this is the optic nerve. Then, you can also see all of these blood vessels.
That are traveling through the retina and then exit the back of the eye in the middle of the optic nerve. So if you look over here on the right, this is a front view of the eye. So this is kind of what it looks like when a looks in to your eye. So here, right here we have what’s called.
The optic disc, and the optic disc is really just the convergence of the retina and where it exits the eye, so this is really actually the optic nerve exiting the back of the eye. And then over here, you have a structure called the fovea. And the fovea is the portion of the retina with the highest density of cones.
Which are the nervous receptors that correspond with color and more high resolution. So this is the portion of the retina that produces the highest resolution image. So, in a sense, you can kind of think of the fovea as producing an HD or a high definition quality image whereas kind of the more periphery of the retina on the outside will produce a much lower quality image.
Diabetic nephropathy al presentation treatment NCLEXRN Khan Academy
Diabetic nephropathy is one of the most common and serious chronic complications associated with diabetes mellitus. In this tutorial, let’s discuss how the mechanisms underlying diabetic nephropathy correlate with the al presentation as well as the treatment of the disease. Now fortunately the mechanisms.
Underlying diabetic nephropathy, directly correlate with the al presentation. And the first al finding of the disease is somewhat paradoxically an increased kidney filtration rate or glomerular filtration rate. So, diabetic nephropathy, if you break down the term into nephro and pathy literally means kidney disease caused by diabetes.
Now typically kidney disease is marked by a decreased filtration rate, so why is it that the first al stage of diabetic nephropathy is that of an increased glomerular filtration rate? Well recall that the earliest mechanism contributing to diabetic nephropathy is an increased pressure state, over here in blue.
And this is due to hypertension and efferent vasoconstriction. So let’s use a common garden hose to help illustrate how this increased pressure state will ultimately result in an increased glomerular filtration rate. So, imagine you have this garden hose and it has a small hole in the middle of it.
So first you’re gonna open up the spigot and increase the pressure and flow through the hose. Intuitively, this is going to increase the rate at which water is leaking from the hole in the hose. Next, you partially kink off the end of the hose distal to the hole, and once again this is gonna further increase the rate at which water leaks from the hose.
This is essentially what’s occurring in the glomerulus with the hypertension representing the opening up of the spigot and increasing the pressure before the glomerulus, in front of the glomerulus, and the efferent vasoconstriction representing the kinking off of the hose, which causes this back pressure.
Both of which are going to increase the filtration rate. This stage of diabetic nephropathy is most commonly asymptomatic, so it goes typically unnoticed. However, it’s going to set the stage for the next al step of diabetic nephropathy; and that is detectable proteinuria. And what proteinuria is is protein in the urine.