Atrial Natriuretic Peptide Hormone (ANH) (Nursing)

00:00 ANH has got a few different names. So, you see there we have atrial natriuretic peptide hormone, ANH, is also called 2 other names. One is atrial natriuretic factor or you may see it as atrial natriuretic peptide. So, whether you see ANF, ANP, ANH, we're talking about the same type of hormone. Now, if you look at the levels there as a young man, Jose has a level of 19 during the day, 17 during the night. So a little bit lower but let's take a look at Jose. Here you're going to see a really big difference. Whoa, look at that.

00:45 So, comparing the daytime of young and old Jose, wow that's more than twice as much.

00:52 Looking at the nighttime of young Jose and old Jose, well this is going to tell you this is a huge factor on why he has to get up and urinate during the night. Okay, so so far we just told you surface level. You know that if you have less ADH you're going to pee more at night and if you have more ANH you're going to pee more at night.

01:14 But I haven't really explained yet how that actually works. So, this is going to be a really cool thing on what your body does and we've got some great graphics for you to understand. So, ANH is this atrial natriuretic peptide hormone. Okay, so you have more of it secreted as you age. Again, we're using that repetition to help this stick in your mind. So, see these little ANHs we got rolling around there? Key point I want you to have is that you have more of this hormone as you age. Now it's a polypeptide hormone and it's released when the atrial myocytes, now those are the muscle cells in your heart and the atrium, when they're responding to atrial stretch. Okay, so what are the things that would cause the myocytes in my atrium to stretch be moved? Let's take a look at how that works. So, atrial volume receptors are also veno-atrial stretch receptors. I mean we have super long names for everything. Don't we? But take a look at our picture here. You see the heart? Orient yourself to where the aorta is. Good job. You see the ventricles at the bottom? And at the top the chambers are called the atrium. So now you got those little squares in there. Right? Because that's what we want you to focus on. These are low pressure baroreceptors. Okay and they're found in the atria of the heart. Now this should kind of make sense because where does all the blood return to the heart on the right side? Aha. The right atrium.

02:55 So, those receptors are there peaking up like whoa we have far more volume on-board these, what are these, low pressure baroreceptors that are found in the atria of your heart are registering we've got a lot of volume. There is stretch in those atrial myocytes because there is more volume involved in my intravascular space. Now sometimes this is a concept that's tricky for beginning students to understand. If you're a senior student and you got this, just hang with this and enjoy the ride. They already know this information. But remember, your heart and your circulatory system is a closed system, enters the right atrium, goes to the ventricle, through to the lungs, comes to the left side, back out to the body, loops all the way around, and comes right back up to your right atrium. The more volume that is in that intravascular space, your veins, and your arteries, the more stretch there is going to be in those atrium. That's because we have those cool baroreceptors there. It also helps us perceive what's going on in your body and allows your body to start. So the takeaway points from here are, I want you to know first of all "Do I have more or less ANH as I age?" More. I have more and that's about its way of protecting itself. What are the veno-atrial stretch receptors? They can also be called atrial volume receptors. What are they? That's another name they go by. Right. They are low pressure baroreceptors and they're in the atrium in the heart. Now in our drawing there are those little squares there.

04:38 And you know the more volume you have, the more stretch they're going to recognize.

04:44 So, atrial stretch is when the blood pressure or volume overload at the atria causes those cells, those cardiac myocytes that are in the atrium, that cause them to stretch or get longer and that's what we mean when we say increased stretch. So that extra volume on board in your intravascular space is what causes that stretch. Now increased atrial stretch leads to increased ANH. So how do we end up with excess ANH? Well the body senses we have more volume on board. Right? That stretch it causes ANH to be released. Now ANH is the...right, it's the hormone. That's the one. Now let's look at what the hormone does. Look where we are. We're right back in the kidney, the little round circle though it looks like antennae but really your blood supplies, that is a tangle of capillaries inside Bowman's capsule. Now look at ANH there. We know that ANH's job will end up increasing the amount of urine that we put out of our body. So, what do you think is going to happen? What 's ANH going to do in this part of our kidneys? Can you predict what you think is going to happen? Now let's take a look. So, ANH stimulates vasodilation. Now that means you have increased blood flow, increased glomerular filtration rate. That's a good thing for kidneys. Right? So when we have an increased blood flow, an increased glomerular filtration rate, our kidneys are filters. And as we're putting more through it up to a point as we're putting more through it what's going to happen? Well take a look at what happens. When we have extra blood flow, we've got things going through here. But see that right there? We're going to block sodium and water reabsorption. That's what happens with ANH. So, I have extra volume on-board. I know that older people have extra ANH. I know that the role of ANH is that it's going to increase the blood flow and increase the GFR so I'm going to end up with extra urine being produced. Another reason why poor Jose is having to get up in the middle of the night. So when we're talking about this ANH when you have the increased glomerular filtration plus you have the blocking or the inhibition of reabsorption, that's why you end up with increased excretion of water and urine volume or the term diuresis. So that is why Jose has increased diuresis at night. So, let's do a quick review that was a lot of information. Which 2 hormones cause older people to have to get up more often during the night to pee? Best answer? ADH, antidiuretic hormone, and ANH.

07:52 There they are for you right on the screen. So, what I'd love for you to do...pause the video and just write yourself some notes about what you recall and you remember about ADH and do the same thing with ANH.