Organization of the Body

This post is going to detail the different aspects of organizing the body, such as body directions, planes of section, and body cavities, while using the correct anatomical terms.

The picture above displays the anatomical position. This position requires an erect body, palms and face directed forward. This position is very common in anatomy, as it easily shows correlation between the parts of the body.

The next picture demonstrates body directions in regards to what is located above/below another body part while the body is in anatomical position. These directions are known as "Superior" and "Inferior". For an example, the head is superior to the waist while the feet are inferior to the knees.

This next picture also demonstrates direction, though this focuses more on "in front" or "behind". In anatomy, this is referred to as "Anterior" and "Posterior". The navel is anterior to the spine, and the spine is posterior to the navel.

The next two images featured below illustrate two different body directions. Medial refers to body parts located toward the midline of the body while lateral refers to body parts located away from the midline of the body. The spine is medial to the shoulders while the shoulders are lateral to the spine.

Due to the mobility of appendages, there are specific directions to classify what is close/far relative to the body. The farther something gets from the trunk is described as distal while the closer something is to the trunk is described as proximal.  The fingers are distal to the elbow, and the shoulder is proximal to the wrist. 

The last directional terms we are going to discuss are superficial and deep. These reference how close  something is to the surface of the body. The spine is deeper than the skin, and the skin is more superficial than your skeleton.

Newt, we are going to go over the planes of the body. The Saggital Plane divides the "left" and "right" sides of the body.

The Transverse Plane divides the body into superior and inferior sections. 

The Frontal Plane separates anterior from posterior.

The body also has many cavities, or spaces that have the potential to be hollow. The picture below shows many of these cavities. You can even go to a smaller scale than that shown, for example, the nasal cavities, orbital cavities, etc.

https://nhspe.wikispaces.com/file/view/body_cavities.jpg/88623997/body_cavities.jpg

Another think to look at are membranes, specifically those surrounding the heart, which are illustrated in the picture below. The visceral pericardium membrane directly covers the heart, with the parietal pericardium membrane on the outer side. The pericardial cavity divides the two, which is filled with biological fluids.

https://40.media.tumblr.com/tumblr_lslxk9mJMR1r4qjgpo1_500.png

The last thing we are going to discuss in this post is the regions of the core/trunk. There are nine of these regions. They help organize the abdomen and the parts of the body associated with it. 

http://www.newhealthguide.org/images/10434100/image001.jpg

There you have it-the basic ways to organize the human body! 

Let's Talk About Homeostasis

Today we are going to talk about homeostasis and figure out exactly what it is, while learning about some examples and important terms.

To begin, let's find out what homeostasis means. By definition, it is "the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes." So, essentially, homeostasis is where the body uses physiological processes to maintain a balance and stable environment within the body.

http://iws.collin.edu/mweis/Images/Fireworks%20Drawings/2401%20related%20drawings/drawings%20in%20fireworks/body,%20cell,%20tissue/body_chem/drawing_homeostasis.png

We are constantly putting our bodies through changing environments and altering the patterns of what we consume, but even so, our bodies manage to stay balanced through homeostasis. For example, when the environment outside of the body is cold, homeostasis makes sure the internal systems inside the body keep it at the correct temperature. 

https://kristinaarquettenutrition.files.wordpress.com/2011/07/how-the-body-loses-heat.jpg

The picture above illustrates another example of homeostasis. As you run, your body generates more heat than when you are at rest. Your body is also subjected to the weather outside, and must adapt to the temperature to maintain an internal balance. To do this, homeostasis causes increased respiratory, sweat, and radiation production. 

Another important part of homeostasis is feedback. Feedback is separated into two categories: positive and negative. 

Negative feedback- "the diminution or counteraction of an effect by its own influence on the process giving rise to it, as when a high level of a particular hormone in the blood may inhibit further secretion of that hormone, or where the result of a certain action may inhibit further performance of that action."

Negative feedback isn't a "bad" thing. Basically, something happens to your body, such as an increase in your blood glucose level, and as a result, your body has a reaction, such as secreting insulin that stores the glucose as glycogen. Because of the insulin reaction, your body begins to detect lower levels of glucose, and therefore, slow insulin secretion. This is negative feedback; your body was able to balance blood glucose levels by starting/stopping insulin production. This example is illustrated below.

http://sjesci.wikispaces.com/file/view/EndocrineNegativeFeedback.gif/174597715/EndocrineNegativeFeedback.gif

Positive Feedback-"the enhancement or amplification of an effect by its own influence on the process that gives rise to it."

Positive feedback is basically where your body detects something and reacts to the change. Unlike negative feedback, the body continues to react until the disturbance is completely controlled. For example, when a woman is giving birth, the baby's head being pushed causes nerve impulses which lead to the contraction of the uterus. This pushes the baby forward, and again, a contraction occurs. this cycle repeats until the baby is pushed out. This example is also shown below. 

https://courses.candelalearning.com/anatomyphysiology2/wp-content/uploads/sites/30/2014/07/106_Pregnancy-Positive_Feedback.jpg

So there it is-the basics of homeostasis, its functions, and positive/negative feedback!