Skeletal Muscles: A Case Study

This activity is the critical driving force of muscle contraction. The stream of action potentials along the muscle fiber surface is terminated as Acetylcholine at the neuromuscular junction is broken down by acetyl cholinesterase. The release of Calcium ions is ceased. The action of the myosin molecule heads is obstructed because of the change in the configuration of troponin and tropomyosin due to the absence of calcium ions. This will eventually cause the contraction to be ceased. Together with these physical processes, an external stretching force such as gravity pulls the muscle back to its normal length.

Anemia is a disorder of the blood. It occurs when your body does not produce enough erythrocytes or red blood cells (RBCs). Without the erythrocytes oxygen can not be adequately delivered to the tissues and organs throughout the body. This will cause you to become weak and tired. A person may also experience headaches, skin pallor, and faintness. Your body may attempt to compensate for these symptoms by speeding up the heart rate and respiratory rate. This is the body’s attempt to return oxygen levels to normal(Thibodeau and Patton, 2005).

As the concentration of hemoglobin in the Red Blood Cells falls below normal, the total Red Blood Cell count consequently decreases. Therefore, oxygen cannot be adequately carried. (http://www.mayohealth.org/mayo/pted/htm/iron.htm).

“Erythrocytes contain haemoglobin, an important respiratory pigment that is essential for human life” (Strech, Beryl; Whitehouse, Mary;, 2010) Haemoglobin is very important because it is an iron-containing protein.

Hemoglobin is a globular protein in red blood cells that carries oxygen to the tissues and carbon dioxide to the lung for release. This protein expresses cooperative binding, which makes it ideal for gaseous transport throughout the body. Another protein, myoglobin, has a higher affinity for oxygen in comparison to hemoglobin and is located at the tissues to accept the oxygen from hemoglobin. The kidney hormone erythropoietin (EPO) is the primary regulator of erythropoiesis, which is the production of red blood cells. The body increases the production of this hormone in response to low oxygen conditions to increase the number of oxygen carriers in the blood.

In the medical field, blood transfusions are used to replace blood lost due to emergencies or in patients with conditions that lower red blood cell count like anemia and kidney failure. Athletes improve performance and stamina by using either autologous transfusion, during which their own blood is drawn and stored for future use, or homologous transfusion during which athlete recessives blood from a donor. Erythropoietin is a hormone produced by body to stimulate red blood cell production. In patients with anemia, stimulation of erythropoiesis improves energy and ability to perform daily tasks, but in athletes it greatly increases performance by improving the delivery of oxygen to tissues. Synthetic oxygen carriers like HBOCs and PFCs have the ability to carry additional oxygen, and it is used as therapy when a blood transfusion is needed but no human donor is available. Athletes use synthetic oxygen carriers to achieve the same performance-enhancing effects of other types of blood

IN RESPONSE TO DECREASED BLOOD OXYGEN, THE KIDNEYS RELEASE ERYTHROPOIETIN INTO BLOODSTREAM. INCREASED ERYTHROPOIETIN STIMULATES RBC PRODUCTION IN RED BONE MARROW, THIS PROCESS INCREASES BLOOD OXYGEN LEVELS, RESTORING HOMEOSTASIS. WHICH WILL INCREASE HEMOTOCRIT.

Over a century ago Eugene Goldwasser and Takaji Miyake worked together in Chicago to synthesize the human hormone erythropoietin, better known as EPO. It took over 10 years for EPO to be approved by the Food and Drug Administration to be used solely for patients with anemia. EPO is naturally produced by the kidneys and is sensitive to the oxygen levels in the blood. When oxygen levels are too low, EPO is released and stimulates the bone marrow to produce more red blood cells. Often times a low oxygen level in the blood can indicate that a person has anemia, which is a “condition in which the blood is deficient in red blood cells…”

Since erythrocytes lack a nucleus and mitochondria they have a short life span of a 120 day period (Fox 408). In addition, since red blood cells have a short life span they are constantly being produced in the bone marrow. Erythrocytes main function is transportation; erythrocytes carry oxygen from the lungs to parts of the body that need it for cellular respiration. The protein that allows erythrocytes to transport oxygen is a metalloprotien, called hemoglobin. Each erythrocyte carries approximately 280 million hemoglobin molecules (Fox 408). In addition, erythrocytes carry carbon dioxide from the cells to the lungs, the lungs, and then expel carbon dioxide out of the body through exhalation. The reference concentration range for erythrocytes in an adult male (RBC count) is 4.52-5.9 x10^12 /L (.CLL Support Organization). Red blood cells are extremely important, and if a person does not create enough or does not create enough, this can lead to serious problems. The hematocrit is a ratio of the volume packed erythrocytes to the total blood volume and in a typical adult male the range is around 40-54%. Curtis (2). Hemoglobin (Hb) concentration is a test that measure hemoglobin protein that allows red blood cells to carry oxygen. In certain anemia, people have enough red blood cells but not enough

Anemia: Anemia is a common systemic consequence of chronic kidney disease (CKD) (Shemin, 2014). An individual who has a hemoglobin (Hgb) that is less than 11.0g/dL, is considered anemic (Shemin, 2014). As CKD continues to become worse, the individual is at higher risk for developing anemia. More than 40% of patients in stage V CKD develop anemia (Shemin, 2014). CKD leads to anemia due to a decrease or deficit in the production of erythropoietin (EPO) (Shemin, 2014). Bone marrow receptors are stimulated by EPO, a 165 amino acid protein, the stimulation leads to the production and promotion of red blood cell precursors into mature erythrocytes (Shemin, 2014). Since EPO is synthesized in the kidneys, a decrease in the production of EPO will occur in the presence of CKD due to the kidneys being unable to function properly (Shemin, 2014).

Muscles must be attached at a fixed origin in order for them to function “naturally”. Muscles help the body function by contracting, causing movement in the body. When the muscle contracts, its insertion is actually moving towards its origin. This promotes movements because when you extend your triceps brachii, you are actually causing the straightening of your elbow, or when you Flex your biceps brachii, you are causing your elbow to bend.

This topic of discussion is essential to medicine for many reasons, the main reason being that erythropoietin is the glycoprotein hormone that allows for the production of red blood cells1. Red blood cells are the carriers of essential nutrients, which are needed by the body, such as oxygen2. Recombinant human erythropoietin has proven to be beneficial to patients suffering from anemia, because this serves as an alternative to the endogenous erythropoietin which decreases in anemic patients, causing them to become severely ill1. In the article, it is stated that “the availability of recombinant human erythropoietin has led to widespread therapeutic applications in anemia associated with, for example, chronic renal insufficiency, chemotherapy, and HIV infection1.” However, abusing the use of recombinant human erythropoietin can lead to many detrimental conditions and health problems, such as hypertension and many cardiovascular complications3. Therefore, this intense focus and study was crucial to the understanding of erythropoietin and the effects of abusing recombinant erythropoietin, for the purposes of higher athletic performance. In the laboratory, it is important to understand the differences between these two forms of erythropoietin, and in order to be successful

Erythropoietin is produced by the kidneys and is the hormone that regulates the production of red blood cells. The kidneys don’t make enough erythropoietin, so there are fewer blood cells, which can lead to anemia.

"Anemia can be defined as a decrease in the oxygen-carrying capacity of the blood caused by low hemoglobin concentration" ("A Practical Guide", 1). "Cells in the body require oxygen to fully utilize fuels. The oxygen is transported from the lungs to tissues throughout the body via red blood cells. Oxygen binds to hemoglobin, a specific molecule within each red blood cell. This molecule consists of heme, which is a red pigment, and globin, which is a protein. If the amount of functioning hemoglobin is reduced, a condition known as anemia arises" ("Anemia", 1). "The anemia that may result can take many forms, including that caused by a low iron level (iron

Skeletal Muscle Structure: skeletal muscles cells are like long fiber structures, That contain many nuclei and are subdivided into smaller structures that are called “myofibrils”. The “Myofibrils” are created of two kinds of “myofilaments”. Thin filaments are made of two strands of the protein-actin and one strand of a regulatory protein coiled with each other. Thick filaments are staggered arrays of “myosin molecules”. * Organization Units of skeletal muscle. Filaments are organized into structures called the “sarcomeres”. “Sarcomeres” are created in the following manners: * The Z lines are at the border of the “sarcomere”. They align in adjacent “myofibrils”. *The I bands are areas that are near the edges of the “sarcomere” containing only thin filament. * The A bands are regions where thick and thin filaments overlap each other and correspond to the length of the thick filament.* The H zones are the areas in the center of the A bands containing only thick filament. In vertebrates Cardiac Muscles: are only found in the heart. Muscles cells are branched, and the junctions between the cells contain intercalated discs that electrically connect all heart muscle cells with each other, allowing the co-ordinated actions. These cells can also create their own action potentials. In Smooth Muscles: There are no striations and contain less myosin; the myosin is not associated with specific actin strand.