Homeostasis (Nursing)

00:01 And so, again, I brought up homeostasis in the previous slide and that is because homeostasis is absolutely essential for life.

00:11 Homeostasis is a condition of equilibrium or balance in the body's internal environment and this is maintained by regulatory processes performed by several different organ systems in the body.

00:27 And so when we think about homeostasis, I like to think about it in terms of feedback or feedback loops.

00:37 So there's different ways that we are going to maintain homeostasis and we'll talk about them shortly but in general, what we're going to have is some type of external stimulus that is going to affect a controlled condition.

00:52 There are going to be certain receptors that are going to read or interpret this change or this stimulus and then that input is going to go to the control center, usually the brain, and then from there we will have an output.

01:08 The output is going to affect some part of the body and then from there, we will respond to the altered control condition.

01:17 And that response will allow us to return to homeostasis.

01:22 And so, we just continue this all throughout the day, all throughout life.

01:28 You are constantly responding to different stimuli so that your body can maintain a controlled condition.

01:38 So here's an example of maintaining homeostasis. Let's talk about blood pressure.

01:45 Let's say that you walk outside of your door and as you walk outside of your door, there's a large bear and that bear scares you and causes your blood pressure to increase.

01:58 As your blood pressure increases, there are certain receptors on your blood vessels known as baroreceptors and these baroreceptors actually sense the change in that pressure.

02:12 They send a message to your brain saying, 'Oh my goodness, there's an increase in pressure.

02:17 We must do something.' The brain then sends a message back out to the heart and to the blood vessels telling the heart to decrease the rate and telling the blood vessels to dilate or open up a little bit more so that we can decrease the blood pressure back to normal levels and that is how we get back to the original blood pressure that we would like for our body to maintain in order to perform functions.

02:45 So not all feedback is negative and while it's easy to think about negative feedback, there's also times when we need positive feedback.

02:55 One of the main examples that I can think of for positive feedback is going to be during pregnancy.

03:03 So at the end of pregnancy as it is time for the baby to be born, there's a stimulus that causes the cervix to begin to stretch.

03:12 There are receptors in the cervix that then send impulses to the brain that say the cervix is stretching.

03:21 This then causes the brain to send messages to the uterine walls to tell them to contract and to contract forcefully because now we are about to start the birthing process.

03:34 As the baby is moving further down the birth canal, the cervix is going to actually stretch more.

03:42 So the movement of the baby down the birth canal actually causes the cervix to increase in stretch instead of going back to the original size.

03:52 So then how do we get back to original size? Usually, interruption of this positive feedback loop occurs once the baby is born and the cervix no longer needs to stretch.

04:03 And once that happens, then we break this feedback cycle and the cervix returns to normal.

04:11 So when we're maintaining homeostasis, our body is happy.

04:15 However, when there is an imbalance or homeostasis is disrupted, this can lead to disease, disorders, or sometimes even death. So how are we able to maintain homeostasis? Our genetic makeup is -- plays an important role but if there is something wrong in the genetic makeup, if something is not coded correctly, this can affect our homeostasis -- our homeostatic balance.

04:44 Also, the air we breathe plays an important role as well.

04:49 It's very interesting but the components of the air, the composition of the air is very important and when we take in chemicals and other things that our body is not suppose to inhale, that can also affect homeostasis of the body.

05:06 The foods that we eat are vitally important to our body's ability to perform functions and we must make sure that we eat a balanced diet so that we have all the nutrients available to our body to maintain homeostasis.

05:23 Lack of or too much of a certain chemical or nutrient in the body can severely affect homeostasis as well.

05:36 And lastly, one thing that you may not even realize is the thoughts that you think can also affect your homeostasis.

05:44 And so it's important that we maintain a positive attitude as much as possible in order to maintain homeostasis as well.