Alzheimer's Disease

Ever since I was nine years old I have been interested in working with the elderly. I believe my passion started when I helped my mother take care of my grandmother that was dying of breast cancer. One area that always intrigues me is Alzheimer's Disease. It saddens me that people forget who their family members are, forget how to eat, forget how to walk, and even forget how to breathe. Even though this disease is so sad, I find it extremely interesting.

Early symptoms of Alzheimer's Disease are loss of recent memory, spatial disorientation and lessening of emotional responses. In the second stage higher learning functions deteriorate, the ability to read and write are lost, the person becomes confused and doesn't recognize family members. In the third stage the person can experience seizures and are unable to speak.

What I find interesting is what is actually happening in the brain to cause these things to happen to older people. What is believed to cause Alzheimer's Disease is atrophy of the brain. There is a loss of neurons, enlarged cerebral ventricles, neuritic plaques and neurofibrillary tangles form in the hippocampus and cerebral cortex, and there is a deficiency of acetylcholine-releasing neurons.

I found a very helpful website that shows in many different aspects how the brain changes that is suffering from Alzheimer's Disease. The link is: http://www.alz.org/braintour/alzheimers_changes.asp

Extra Post

This is my extra post to make up for one that was previously missed. I want to focus this post on the circulatory system. We have learned that there are many different functions of the circulatory system. Some of them include: brings blood containing nutrients, oxygen, and hormones to cells, transport wastes away from cells, fights infections, regulated body temperature, and helps stabilize pH concentration of bodily fluids. The circulatory system is made up of the heart, blood, arteries, veins, and capillaries.

The heart is a muscular pump which moves blood throughout the body and sits in a pericardial sac. There are three layers of the heart: the pericardium, myocardium, and endocardium. The pericardium surrounds the perimeter of the heard and is a protective sac of connective tissue. The myocardium is the muscle of the heart which is made up of  contracting cardiac muscle fibers. The endocardium is the inner surface of the myocardium. The heart has four chambers: two atria and two ventricles. The atria are the two upper chambers and then receive blood from veins and send blood to the ventricles. The ventricles are the two lower chambers and they receive blood from the artia and pump blood out through the arteries.

Since the flow of blood through the heart is an important process to understand, I found a video that helps explain each step of the process. The link is: http://www.youtube.com/watch?v=Rj_qD0SEGGk

Special Senses

This week we have started to look at our senses and how they can change with age. We first looked at the eye. There are 3 different layers of the eye: the Fibrous Tunic, the Vascular Tunic and the Nervous Tunic. The fibrous tunic contains the white and opaque area known as the sclera, and the cornea. The vascular tunic contains the choroid coat, the ciliary body, and the iris. The nervous tunic contains inner nervous tissue layers, robs and cones, and this is where the nerve fibers synapse to form the optic nerve. Some of the age related changes with the eye are: slight shrinkage of the eye, increase in connective tissue, degeneration of cells, reduced blood supply, skin of the eye lid thins, and there is a loss of fat and elastic tissue around the eye. Other conditions related to aging are glaucoma, diabetic retinopathy, cataracts and macular degeneration.

I found a video that further explains how light enters our eye. The link is: http://www.youtube.com/watch?v=15P8q35vNHw

Parkinson's Disease

Parkinson's Disease is one that affects the neurons that make Dopamine. It is a disorder that leads to tremors, difficulty walking and difficulity with coordination and movement. There are three genes related to Parkinson's and they aer SNCA, LRRK2, and MAPT. There are several symptoms related to this disease. Some of them include: tremors, blinking, low blood pressure when getting up, difficulty swallowing, drooling, loss of small hand movements, stiff muscles, anxiety, stress, confusion and depression. There is no cure for this disease but medications are used to increase the level of Dopamine in the brain. The two types of Parkinson's Disease are tremor dominant, and PIGD or partial instability gate of difficulty.

I found an article that discusses the life expectancy of those diagnosed with Parkinson's Disease. The article shows how the life expectancy depends on the age a person is when diagnosed. For example, if you were to get Parkinson's Disease between the ages of 25-39, you could expect to live about 38 more years. If you were to get the disease betweent the ages of 40-64, you could expect to live 21 more years. Finally, if you get the disease when you are 65 or older, you can expect to live 5 more years (Robinson, 2008).

Link: http://www.mdvu.org/emove/article.asp?ID=1013

Muscular System

We have recently been talking about the muscle system. We learned that there are four properties of muscle which are excitability, contractility, extensibility and elasticity. We also learned that there are three types of muscle: skeletal, smooth, and cardiac. Skeletal muscles are attached to bones and make up about 40% of our body weight. They are striated and are voluntary movements. It is hard to see distinct skeletal muscle cells because there is multi nuclei per cell. Smooth Muscle is found in the walls of hallow organs, in the eyes and in the skin. The cells are not striated and they have an involuntary rhythm. Cardiac muscle is striated but not as severe as skeletal muscle. Cardiac muscle has intercalated disks which is how you can tell from cell to cell. We also learned about how muscle attaches to bone through tendons and connective tissue.

I found an article that discusses smooth muscle. I found it interesting that we have over 600 muscles in our body. Muscles are even responsible for making you get sick, or throw up. The article goes into detail about the function of smooth muscle which I found very interesting.
Link: http://kidshealth.org/kid/htbw/muscles.html

Bone and Cartilage

Before break we were learning about bone and cartilage. First we looked at the two different types of bone. There is Trabecular or Spongy bone which gives strength to the end of bones. The second type is Cortical or Compact bone which forms the outside of the shaft of the bone. Dr. Hens often uses the example of the cowboy to explain how bone can reform itself because of forces acting upon it. We then looked at the different parts of the compact bone. The osteon is a unit of bone, or the central cavity. Osteocytes are cells that make up bones and they sit in the bone matrix. The Lacunae is the space between the bones. The three types of cells that are in bones are Osteocytes, Osteoblasts and Osteoclasts.

Hyaline Cartilage is located in the long bone and trachea and is mostly water. Fibrocartilage is located in the spine and meniscus and there is a lot of resistance because of dense collagen. Elastic cartilage is located in the ears and nose.

I found an article on Osteoporosis that had some interesting facts on it. It states that Osteoporosis is the most common type of bone disease and that one in five American females over the age of 50 suffer from the disease (ADAM Medical Encyclopedia). The articles also discusses risk factors as well as symptoms.

Link: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001400/

Tanning Beds

This past week we learned about light damage to the skin. There are two types of ultraviolet light (UVA AND UVB). Even when the sun is not shining, UVA light is still present. It is very powerful, with a wavelength of 320-400 nm. UVA light can even go through some clothing. When a person goes into a tanning bed before the age of 30, they are increasing their chance of getting skin cancer by 75%. This type of UV light is also what is responsible for signs of aging.
UVB light is the type of UV light that causes sunburns. The strength of this light is stronger in the summer and weaker in the winter. UVB light is the type of light that causes most skin cancers.

Since I use indoor tanning beds on a regular basis, I looked up an article on how harmful they really are. According to the article, there are about 30 million people that use tanning beds. Many people believe there are not enough regulations in place concerning tanning beds and that there should be more. This year, there will be about 70,000 new cases of melanoma diagnosed (Reuters 2011). I feel as though tanning beds are kind of like cigarettes. People know how bad smoking is for them, and that cigarettes causes lung cancer, yet they still do it. People know tanning causes skin cancer, yet they still use indoor tanning beds.

Link: http://www.msnbc.msn.com/id/45656187/ns/health-cancer/t/tanning-beds-may-raise-common-skin-cancer-risk-percent/

Cellular Aging and the Integumentary System

It has been interesting to learn about what actually happens to cells as they begin to age. The plasma membrane encounters structural changes. For example, the membrane has less fluidity and this is due to an increase in saturated fats. In the calcium pump, transporters slow down which causes there to be too much calcium in the blood, and not enough in the cell. In the nucleus, there is an increase in DNA damage, a decrease in DNA repair processes which leads to errors in proteins being synthesized, and changes in chromatin. With age, the chromatin becomes more condensed, there is less access for repair enzymes, and there is a decrease in RNA synthesis. There is something in the cytoplasm that inhibits DNA syntheses in older cells. Autophagy is the process used to destroy damaged organelles. Proteins can be broken down by entering a proteosome where it is broken down into amino acids and then released. Finally, in the mitochondria, there is a decrease in the number of post mitotic cells which causes the source of metabolic energy to decrease.

So far, I find the Integumentary System to be very interesting. Part of this may be that all of the material is new to me; but there is just so much going on in our skin that I was unaware of. I would have never thought as our skin to be an organ but it is actually the biggest organ of the body which is composed of all four cell types. The average person's skin in 22 square feet, 1-2 mm thick, and weighs 10 pounds. There are two major layers: the epidermis and the dermis. There are five layers of the epidermis and they include, the Stratum Basale, the Stratum Spinosum, the Stratum Granulosum, the Stratum Lucidum, and the Stratum Corneum.

I decided to find an article that talks about autophagy because I find it to be an amazing process. The article states that autophagy is an homeostatic process where cells break themselves down (Levine et al, 2011). This is an important process with regards to immunity and inflammation. Autophagy occurs because of nutrient deprivation or metabolic stress (Levine et al, 2011). The link to this article is: http://www.nature.com/nature/journal/v469/n7330/full/nature09782.html

Hi everyone!

This week in class we learned about the nine theories of aging. The first theory is called Aging by Program. This theory states that aging begins at birth and that there is a timekeeper. Cells only divide a certain number of times and then they die. The second theory is the Gene Theory and it states that aging is programmed due to bad genes. The third theory is Gene Mutation Theory and it states that accumulation of cells that contain mutations cause the cells to not function properly and eventually die. The fourth theory is the Cross-Linkage Theory and it states that with age, proteins cross-link and are structurally altered. The fifth theory is the Free Radical Theory and it states that if the amount of free radicals in a cell exceed a threshold, the cells become damaged. The sixth theory is the Cellular Garbage Theory which states that accumulations of nonactive and reactive substances interfere with normal functioning of the cell. The seventh theory is the Accumulation of Errors Theory which states that there is an accumulation of random errors in translation of proteins with age. The eighth theory of aging is the Wear and Tear theory which states that cells have a certain amount of metabolic energy and the rate at which the energy is used determines the length of life. The final theory is the Autoimmune theory which states that new antigens cause autoimmune reactions.

I was curious to learn more about the Free Radical Theory because I did not really understand it at first. I found an article that really goes into detail about this theory and allowed me to understand it better. Free radicals have an extra electron which causes the cells to have an extra negative charge (Anti-Aging Today). They bind to other molecules to try and steal electrons. When doing this it causes the other molecule to also become a free radical, thus destroying cells. Free radicals attack cell membranes and create metabolic waste products (Anti-Aging Today).

Link to article: http://www.anti-aging-today.org/aging/theory/free-radical.htm