Objective 9: Compare and contrast bond types

I didn't realize how rusty I was on bond types until I reached this objective. I believe I learned this information awhile back when I was in middle school during physical science, came across it again during chemisty, and then brushed by it in anatomy and physiology 1. So, long story short, I had to refer to chapter 2 in our textbook to become refreshed with this old topic. The textbook does a good job of simply explaining what each bond is on pages 27, 28 and 30. There are three major types of chemical bonds: ionic, covalent, and hydrogen bonds.

Ionic bond:

An ionic bond is a chemical bond between atoms where one or more electrons is transferred from one atom to another. The atom that gains one or more electrons is the electron adapter and it obtains a negative charge (anion). The atom that loses one or more electrons is the electron donor and it obtains a positive charge (cation).

Covalent bond:

A covalent bond occurs when two atoms share electrons and the shared electrons occupy a single orbital common to both atoms. When two atoms only share one pair of electrons, a single covalent bond is formed. When two atoms share two or three electron pairs, a double or triple covalent bond is formed.

Hydrogen bond:

A hydrogen bond is more like an attraction than a true bond. Hydrogen bonds form when a hydrogen atom, already covalently linked to one electronegative atom, is attracted by another electron- hungry atom (greedy-grabby) and a "bridge" is formed between them.


These two photos from our textbook is are examples of ionic and covalent bonds.

(ionic bond)

(covalent bond)



While I was surfing the web, I came across this Youtube video describing ionic and covalent bonds and I just had to add it to this objective. It not only is informative, but it is a very cute video that really made this information stick. I hope you enjoy it as much as I did. When I started viewing it, it made me laugh. But be careful, its quite catchy!

Objective 10: Identify classes of hormones

I really thought that this objective would be a piece of cake, but when I tried looking up the classes of hormones online I got a bunch of different answers. So I decided to refer back to the old trusted textbook and chapter 15 lecture outline to find my answer. Hormones are classified into two main classes, which are amino acid-based hormones and steriod hormones. This information is like common sense now after reviewing the slides and textbook, and it makes me laugh that I tried to make this objective harder than it really was. Both classes of hormones are chemical substances that regulate the metabolic function of other cells in the body.

Objective 60 & 61: Pancreatic juices and chemical forms

Objective 60: Describe enzymatic and bicarbonate content of pancreatic juices
Objective 61: State the chemical forms in which the major food classes are absorbed

Reading up on these two topics was a lot easier than I had originally thought. For some reason, I thought that the pancreatic juices were going to be this complicated mix of enzymes and electrolytes. I also believed that the chemical forms of the food classes were going to have a very long process to being absorbed. Well, I was in for a pleasant shock. I was able to located the information in the text book and lecture outlines, and they both did a great job in helping me understand the two. Pancreatic juice consists primarily of water, electrolytes (mainly bicarbonate), and enzymes (amylase, lipases, nucleases). The acinar cells produce the enzyme-rich component of pancreatic juice. Along with the lecture outline slides, I also referred to chapter 22 page 775 to help me understand the make up of the juice.

I copied this chart from chapter 22 lecture outline, but it can also be found on page 785. It really does a great job in outlining the chemical forms that each type of food gets broken down into. It then tells you the path of absorption that these chemicals forms travel within the body. I don't know how I would have figured out this objective without this chart. Its extremely detailed, and informative and it really made that light bulb go off for me. So what I learned is that carbohydrates are broken down into oligosaccharides and disaccharides; protein is broken down into amino acids; fats are broken down into monoglycerides, glycerol and fatty acids; and nucleic acids are broken down into pentose sugars, N-containing bases, and phosphate ions. After the major food classes are broken down into their chemical forms, it is from there that they are absorbed into different parts of the body. The last column of the chart describes in detail where they are shipped off too. Isn't the digestive system spectacular?

Objective 58: Relate structure and function of the endocrine system to digestion

This is a very broad topic, which means there could be a variaty of answers to cover this topic. I actually am still having a hard time figuring out the best way to answer this question correctly, but I'm going to give it my best shot. So, here it goes. The endocrine system is the second great control system of the body. It is made up of a serious of glands that produce a variaty of hormones. These hormones act as "chemical" messengers and help regulate a majority of the body's basic functions. There is a passage from the textbook that really helps me understand, in short, what the endocrine hormones are responsible for. In chapter 15, the passage on page 519 states "The major processes controlled and integrated by these "mighty molecules" are reproduction; growth and development; maintenance of electrolyte, water, and nutrient balance of the blood; regulation of cellular metabolism and energy balance; and mobilization of body defenses." This really helps me see how the endocrine affects the other systems more clearly. The digestion system is composed of a system of organs that helps break down food into nutrients, absorbs the nutrients into the bloodstream, and then gets rid of the wastes. So in short, the endocrine system produces important hormones (for example -gastrin, cholecystokinin, secretin) that allow the digestive function to take place. Without these hormones, our bodies could not digest the food we take in.

I know that we are not suppose to "teach" the information, but I couldn't find anything in the textbook or online that really gave me an "aha" moment. There was a small article called Enteric Endocrine System that provided a few small pieces of information that guided me, but for the most part I was on my own. Being able to write this information out on this blog really gave me a clearer understanding on how the endocrine system was related to the digestion process. The lecture in class was the only helpful thing to help me understand this information, since we discuss certain topics in depth.

Objective 30: Understand how heart valves ensure one-way blood flow during systole and diastole

Where would we be without heart valves? My best guess would be that our heart wouldn't complete systole and diastole correctly, and our heart wouldn't be able to function. Which means a very bad day! The valves in our heart ensure one-way flow of blood, and that is very important to its function! Without these valves the blood flow would back flow into other sections of the heart that they aren't suppose to be in, for example back into the atrium from the ventricles. The textbook was a great reference, and the lecture outline was a great summary of the hearts valves. When I was looking for a good diagram to back-up the textbook's information, I referred to chapter 17 pages 587-588 which provided a diagram of the AV valves and another diagram of the semilunar valves. Each diagram shows the direction of the blood flow into the heart and the blood flow through the valves. They describe how the valves are either forced open or stay closed to make sure that the blood flows one way and does not backflow. These photos were all I needed to understand this concept and I'm glad they were apart of my textbook.

Objective 74: Distinguish between diploid germ cells and haploid sex cells

Understanding mitosis and meiosis has always been an ongoing battle for me. For some reason when I first learned this concept I always got the two mixed up. I found this chart from chapter 26 page 899 that helped me in figuring out the differences between the diploid cell and the haploid cell. Well, I couldn't get a good picture of it from my camera ( I don't have a scanner) so I used the photo from the lecture outlines, but the photo and information is still the same. I promise. This photo also severed a double purpose because it helps me understand mitosis and meiosis. It never hurts to learn extra information!

So, basically the two cells go like this.

Diploid= Double. There are 46 chromosomes in each diploid cell

Haploid=Half. There are 23 chromosomes in each haploid cell

Through fertilization,  two haploid cells combine to produce a zygote. The zygote has now two sets of 23 chromosomes. So 23+23= 46. The zygote now has 46 chromosomes and is a diploid cell. I'm glad that I finally figured out the difference between the diploid and haploid cells. All I seemed to need was a little math.

This video also reinforces the information that the textbook and class lectures gave me about diploid and haploid cells. Still, having an animated diagram allows me to have a visual to remember the information by.

Objective 65: State the importance of juxtaglomerular cells in secretion of renin

There wasn't too much information on this topic, but I still relied on the textbook and class lectures to understand this objective. I really did stress myself out on this objective, but it really wasn't as hard as I made it seem. I referred to chapter 15 page 539 and chapter 25 page 845 to help me figure this information out. This is what I concluded from the information I read. There are juxtaglomerular cells are enlarged, smooth muscle cells with secretory granules containing renin. These cells become excited when blood pressure falls, and the response is to release renin in the blood. Renin initiates the release of aldosterone to help blood pressure return to normal. There wasn't too much to go on for this topic, but these passages that I did locate aided me in understanding the concept.