Unit 5 Reflection

The first thing that we learned about in this unit was the digestive system. The digestive system all begins in the mouth, where the food you chew forms a bolus. The bolus then moves to the pharynx, which is the passageway from the mouth to the esophagus. When the bolus reaches the esophagus, peristalsis moves the food into the stomach. Once the food has entered the stomach, the food is "mashed up" and covered with digestive enzymes. When the food leaves the stomach, it is then called chyme. From the stomach, chyme travels to the small intestine where absorption of the nutrients and digestion takes place. Your pancreas is located in the small intestine and is imperative for digestion as it produces many of the digestive enzymes, such as lactase which works to digest lactose. The small intestine is also lined with microvilli in order to increase absorption. The food is then moved to the large intestine, which extends from the ileocecal valve all the way to the anus. In the large intestine, the indigestible food is dried out and water is absorbed. Your large intestine also secretes large amounts of mucous in order to lubricate the sides of the intestine. During this unit, youwe did a lab that measured the length of our digestive tract. It is amazing to think that your digestive tract stretched out could be taller than you. Digestive System Lab

The next thing that we discussed was all about metabolism. We learned that there are three states. The first is the fed state. In the fed state, the sugars are absorbed by the intestine and travel directly to the liver while the pancreas releases insulin. In addition, the majority of glucose taken in by the liver is converted to glycogen. Next is the fasting state. In the fasting state, all glucose is used by cells so the body must continue to make glucose available in order to maintain blood glucose levels. During this state, your insulin levels drop while glucagon levels rise. Gluconeogenesis also occurs and the liver synthesizes glucose from amino acids and glycerol. Your liver then converts fatty acids in ketone bodies. Ketone bodies happen when carbs are low and fatty acids need to be broken down for energy. The next state is the starvation state. During the starvation state, your muscles rely solely on adipose tissue for fuel. The brain also switches ketone bodies for fuel in order to conserve protein. How long you survive during this state is dependent on how much fat you have stored. We then talked about organ specialization and how the liver is the "master of the metabolism". The liver's main job is to maintain proper blood glucose levels. We then discussed the major hormones, insulin, glucagon, cortisol, noradrenaline/adrenaline. Insulin will signal high glucose levels while glucagon will signal low glucose level. In conclusion, metabolism essentially depends upon your genetic makeup, the enzymes you produce, hormones, and if you have a good nutritional balance and live a healthy life. In the article "Does Your Metabolism Need an Overhaul" I learned that building muscle is an essential part of maintaining a healthy metabolism as well as preventing diabetes. I found that article very interesting and it definitely got me to do much more than cardio when I am working out.

The next thing we spoke about was diabetes, as it is a disruption in your fuel metabolism. An important hormone when talking about diabetes is insulin. Insulin is the "key" that "unlocks" cells allowing glucose to enter. When a person is diagnosed with type 1 diabetes, that means that your body is experiencing an auto-immune disorder. In this case, your body does not make insulin all and you are considered "insulin-dependent". For type 1 diabetes, you must take insulin shots daily. Type 2 diabetes is more common than type 1 as is occurs mostly in adults. Type 2 diabetes is a resistance to insulin as the body does not respond to insulin properly. In order to manage diabetes, people must try to keep their blood glucose levels as close to normal as possible. In addition, a proper diet and exercise are essential.

Next, we talked all about the Endocrine System. The endocrine system controls the processes involved in movement and physiological equilibrium and hormones are critical for this. One important hormone are steroid hormones. Steroid hormones pass through the cell membrane and then bind to specific receptors. They then enter the nucleus and bind to the cells DNA which then activates certain genes. From there, mRNA is synthesized in the nucleus and enters the cytoplasm and promotes protein synthesis for things such as tissue growth and repair and regulation of enzyme function. Homeostasis is maintained in the endocrine system by negative feedback, secretion of a specific hormone is turned on or off by a specific physiological change.

The last thing that we talked about was the lymphatic system. The major functions of the lymphatic system are immunity, lipid absorption, and fluid recovery. Lymph is the fluid that flows within the lymphatic vessels. Lymphatic tissue is specialized connective tissue that contains lymphocytes. Lymph capillaries are located everywhere in the body, except bone marrow, cornea, and the cartilage. Another major part of the lymphatic system in lymph nodes which help to filter lymph by trapping foreign substances and then are destroyed by immune cells.

Since I came up with my new year goals, I believe that I have been following them pretty well. Now that we are into February, I want to continue the momentum that I have going. A lot of times, as the year goes on I tend to lose motivation so I hope to continue the motivation that I have right now.