Monday, May 2, 2011

Objective 1: Understand overall body homeostasis with specific regard given to the effects of aging and stress on each system

I had to refer way back to chapter 1 page 8 to remember the exact defination of homeostasis. The book states: homeostasis is a dynamic state of equilibrium, where every organ system plays a role in maintaining the balance of the internal enviroment. Homeostasis consists of a control center that analyzes any stimuli that the body may come across and acts accordingly to make sure the body maintains it homestatic state. The body uses negative and positive feedback mechanisms controls in response to stimuli that knocks our bodies balance off. Each organ system works closely together with its own unique functions to allow our bodies to stay in harmony. So we have this body in perfect harmony, but what effect does stress and aging have on the body?

The textbook really doesn't have an exact answer for the effects of stress and aging on each body system, so I had to take my search elsewhere. I found this site about the effects of stress on each body system on a stress relief site called I know first hand that stress can do major damage to our body systems. I take one of my older sisters for example. She's a very anxious person, which causes her to get stressed out over EVERY little thing. I'm not exaggerating, I mean everything makes her freak out. She's always worried about bills, relationship problems, money problems, and she believes that everything bad happens to her. So she stress herself out so bad that she is always constantly sick, and it's usually for weeks at a time. That can't be good for her body. But this makes complete sense because stress has an effect on lowering our immunity. This explains why she is always sick.

I found a blog called The effects of aging on the body systems which gave me some very useful information on how aging effects the body systems, just like the title of the article states. But the effects of aging on the body system is something I see first hand at work every day. I work as a C.N.A out at a new nursing home called NHC on Okatie Hwy, and I have been working as a C.N.A for almost a year now. So aging on the body system is something that I see and deal with everyday. Not to mention, I take care of an Alzheimer's resident during the day and I can see how aging and disease has affected him. When our body ages, our skin becomes thin and continence becomes a thing of the past. There may be pains in joints that were never there when you younger, and vision is not as sharp as it used to be. Everyday I help take care of people who can no longer stand up because of arthritis, or change briefs because they are no longer able to tell when they have to go. So this part of the objective is very familar to me because I am around aging and its effects on our body systems all the time.

Objective 11: Understand structure and function of the endocrine system in relation to growth and homeostasis

This another one of those objectives that I just can't figure out the right answer. I've been sitting here racking my brain to try to think of the right answer that could fulfill this objective and I keep coming to a road block. But I'm going to give it my best attempt. Okay, here it goes.

The endocrine system is an amazing system that interacts parallel to the nervous system to cordinate and intergrate the activity of body cells. The endocrine system uses hormones (chemical messengers), instead of the electrochemical impluses by neurons from the nervous system, and releases them into the blood. These chemical messengers travel to their "target" organs and effect them in certain ways. The endocrine system uses hormones along with negative and positive feedback mechanisms to maintain the bodies homeostasis.  The anterior pituitary gland of the endocrine system secretes growth hormone (GH), which causes most body cells to increase in size and divide. This hormone allows us to grow. I know I probably didn't get anywhere near close to the right answer, but to be honest I'm still a little lost when it comes to this objective. The Interactive Physiology site did help me understand the structure and function of the endocrine system and how it helps aid in our bodies homeostasis.

Objective 14: Endocrine System

Objective 14: Describe the location, histology, hormones, and functions of the thyroid gland, the parathyroid gland, the adrenal glands, the pancreas, the ovaries, the testes, the pineal gland, and the thymus

WOW! I'd have to say that this is alot of information that is wanted on one objective. I was pretty overwhelmed when I saw it and wondered, 'how on earth am I going to get that one done?' The textbook was a great help (as always) but what really helped our with the location and functions of the endocrine system was our textbook's Interactive Physiology website. I know I have used this site for numerous objectives (like for the respiratory system and alimentary canal), but it has done wonders for me! I really would be kind of lost without it. I had to click under the tab of endocrine system, go to anatomy review, and then just sit back and soak everything in. This interactive lesson not only shows the location of these glands, but also the hormones they secrete and the functions that they perform on the body. Three for one deal? I'll take it! The same site that I used for the histology of the alimentary canal and the respiratory system is the same one that I used for the endocrine system. I wasn't able to take many good pictures of the slides from our labtime (most of the pictures were blurry), so having this site was a great reinforcement. I also found this picture that was helpful, and it shows the location of all the endocrine glands along with their hormones and functions within the body. The endocrine system is a complicated system as it is, so I'm glad that I have sites that can offer me help with multiple objectives.

Sunday, May 1, 2011

Objective 78: Distinguish among the different parts (gross and histological) of the alimentary canal in terms of structure and function

Again, the Interactive Physiology section of our textbook's website is absolutely amazing! This animated review not only goes over the structure of the alimentary canal, but it goes over the functions as well. This review allowed me to interact with the alimentary canal because I could click my mouse over certain organs and the review goes into detail about the functions of it and shows its internal structures. I don't know how many times I referred to this site to help me on my quest of completing these objectives, but I'm glad that our textbook provided it. I would have been so lost without this site, but the textbook and class lectures were also very helpful in my understanding of this important body system.

The histology portion is something that I still can't wrap my head around. Hopefully one day the information will just make sense, but as of now I'm totally clueless in front of the microscope. For some reason I can't tell one thing from another and it is very frustrating. The same Histology site that I used for respiratory system was great in helping me understand the alimentary canal as well.

Objective 43: Describe the anatomy and histology of the nose, pharynx, larynx, trachea, bronchi, and lungs

I could have very easily put this objective with the blog that contains objectives 44-47, but that would have made that entire blog extremely too long. This objective is very closely related to objective 44-47, and in fact the MyA&P Interactive Physiology site is a great help in understanding the anatomy of the respiratory system. This site describes each part of the respiratory system in great detail, and I was also able to interact with the slides to go even further into the anatomy of the respiratory system, such as the lungs and the bronchi. What this amazing video does not cover is the histology portion of the respiratory system. Now, I have to admit there is no way that I can say that I enjoyed the histology portion of any body system. Histology is hands down very confusing, and I still have trouble with it at this very moment. If you put me in front of a microscope I couldn't tell you what it even was, let alone its function. I wasn't able to get great  histology pictures of the nose, pharynx, larynx, trachea, bronchi or the lungs but I was able to find a great site that did.

Objective 57: Justify the role of lacteals in transporting products of digestion

Lacteals are highly specialized lymphatic capillaries that are located in the crypts of the villi of the intestinal mucosa. But since they are located in the villi, how do they transport products of digestion? I referred to both the lymphatic and digestive chapters for my answer (page 657 and 767) and it helped me understand these important capillaries. The lacteals play a huge role in absorbing digestive fats (chyle) from the intestine and then leads it to the thoracic duct, which ultimately sends it to the left subclavian vein. Being able to review the diagram from chapter 22 page 768 gave me a better insight on the structure of the lacteal and how it plays a role in absorbing chyle. I also reviewed the histology of the lacteal, and with both these diagrams and the information from the book I was really able to have a light bulb click on for me.

Objective 56: Examine differences in metabolic and respiratory acidosis and alkalosis

Here is another objective that I figured would be so complicated to understand, but I'm very glad to say that wasn't the case at all. I referred to chapter 25 page 886-887 and it provided some very good information on these topics. The chart on page 886 (included below) was also a great help in understanding metabolic and respiratory acidosis and alkalosis, because the chart also explains what the causes and consequences are of each acid-base imbalance. Hey, a little extra information never hurts if it helps you better understand the concept, right? So this is what I gathered from the textbook about what each one was.

Respiratory acidosis: (The most common cause of acid-base imbalance)
Respiratory acidosis is characterized by falling pH and rising partial pressure of carbon dioxide. It occurs most often when a person breathes shallow or when gas exchange is hampered by diseases

Respiratory alkalosis:
Respiratory alkalosis occurs when carbon dioxide is eliminated from the body faster than it is produced, causing the blood to become more alkaline. This often occurs from stress or pain.

Metabolic acidosis: (Second most common cause of acid-base imbalance)
Metabolic acidosis occurs when their is a low blood pH and low HCO3- levels. Typical causes of this are too much alcohol (Hello hangover!) and excessive loss of HCO3-.

Metabolic alkalosis:
Metabolic alkalosis occurs when their is a rise in blood pH and a rise in HCO3- levels. Typical causes of this are vomiting of the acidic contents of the stomach and an intake of excess base (Hold off on those Tums please!).