Assignment details This assignment will involve describing the physiological mechanisms in place for a particular body system to maintain homeostasis of a particular factor such as blood calcium, fluid volume, blood pressure etc. While normal functioning should be the main focus of the assignment it should; however, include a brief description of how homeostasis is disrupted leading to the appearance of disease identified in topic provided. Please note, the disease process is a minor focus. The assignment will also require the construction of a concept map that summarizes how a physiological system maintains homeostasis normally and how it can be disrupted to cause disease. Submit assignment as a Word document, however, if you intend to use Power Point to produce your concept map and paste it into your word document. In order to copy your concept map, while in PowerPoint you will need to group (In format tab) the whole map together and then copy and paste it into your word file as a picture. The written section should be about 700 words (+/- 15%) excluding references. Assignmnet Description Following the initial written section your concept map should identify the central physiological mechanism in the case. Ensure that the relationship between the components are clearly identified and how they maintain homeostasis. The factors disrupting homeostasis and therefore causing disease need to be positioned appropriately in the concept map. Check the assignment rubric to ensure you have covered all the required aspects. Assignment Structure: The Assignment will have the following sections: Introduction: An introduction should briefly describe the body system associated with the topic and identify its general role briefly. This should be followed by an identification of the factor/s influenced by the body system (in relation to the question) and why they need to be kept within a homeostatic range. Lastly, briefly describe what factor/s in the case disrupt homeostasis to cause disease. (100 – 200 words) Body: The body of your descriptive piece expands on what was identified in the introduction. The mechanisms used by the body system to maintain homeostasis of the factor identified should be described. An explanation of how factors identified in the question disrupt the homeostatic mechanisms to cause disease should be provided and conclude with what could be expected to occur with such disruption. A final sentence should indicate that the processes identified are summarized in the following concept map. (500 words) Summary Concept Map: Explained in the following slides. A note on referencing: Appropriate in text referencing should be used along with the provision of a reference list. It is expected that 3-5 citations would be appropriate and that they are relatively recent (within the last 6 years). You should make use of your text book as a significant reference. **Use at least one journal article and NO website references-they are not reliable sources** Case study question: Case study 2 (Family name I through to Z) Diabetes Insipidus: The hypothalamus plays a key role in maintaining homeostasis. Explain the mechanism by which the pituitary gland contributes to maintaining normal blood osmolality. Why might an individual with diabetes insipidus present with dehydration? What is a Concept Map A diagrammatic summary of how we think and see relationships between bits of knowledge. Concept maps can produce an overall picture of their topic and how interacting sub-components contribute to the overall outcome. The figure on the next slide from your text book is a concept map of how the body maintains glucose homeostasis. Glucose balance is at the center of the diagram with alterations in blood glucose above or below homeostatic levels stimulating physiological mechanisms to return levels to normal. For example insulin is secreted when glucose levels rise leading to storage of glucose in the liver as glycogen and increased glucose entry into cells. The net result is a return of blood glucose levels towards normal. The various bits are linked by text to clarify their relationships. The complexity of the concept map can easily be increased by introducing the membrane receptors on the tissues influenced by insulin therefore explaining the molecular activity of insulin. It is important to establish the level of detail that should be represented or required for your assignment. While diagrams of the liver and pancreas are used, this is not necessary the concept map could simply use boxes representing the various tissues and their processes. Concept Map and disease The impact of disease could be represented on this concept map by introducing Type 1 diabetes for example. The latter is a consequence of islet cell destruction in the pancreas and therefore the cessation of insulin production. Without insulin cells can not take in glucose and therefore blood glucose levels rise (hyperglycaemia) which results in the acute and long term complications of diabetes. I have included some extra boxes in red as an example of how you might show the impact of the disease. In this assignment the impact of the particular disease process identified in the given topic will need to be incorporated into your concept map. How homeostasis is disrupted to cause disease should be clearly identified. Example layout structure of concept map Topic X: Describe the process of erythropoiesis. Why might Vitamin B12 deficiency result in anaemia? Introduction The blood consists of plasma (55%), a buffy coat layer (<1%) and an Erythrocyte layer (45%) and has three functions; distribution, regulation and protection. The erythrocyte layer of the blood transports oxygen around the body in the haemoglobin. Erythrocytes are produced by the mechanism of erythropoiesis which is a result of when the hormone erythropoietin (EPO) stimulates the bone marrow to create more erythrocytes, therefore making the oxygen levels in the body rise (Marieb & Hoehn, 2014). Anaemia is a condition where inadequate oxygen levels are being carried by the erythrocytes, due to a reduction of erythrocytes, inadequate haemoglobin or a lack of oxygen in the blood. An example of this is Pernicious anaemia which prevents erythrocytes from dividing and producing more of themselves therefore significantly reducing the amount of oxygen in the body (Marieb & Hoehn, 2014). Discussion Erythrocytes are biconcave discs that have no nucleus and contain haemoglobin which contributes to gas exchange involving oxygen and carbon dioxide. Oxygen is carried around the body by the haemoglobin as oxygen doesnt dissolve well in plasma in the blood (Huether & McCance, 2013; Marieb & Hoehn, 2014; Grossman & Porth, 2013). These erythrocytes are vital for homeostasis and are regulated by the mechanism of erythropoiesis which is responsible for the normal production of erythrocytes in the body. The erythrocytes are produced in the red bone marrow but are not directly stimulated there by the hormone EPO, they are stimulated in the Peritubular cells in the kidney (Grossman & Porth, 2013). There is always a balance kept to ensure that there are not too many or too few erythrocytes in the blood, this is where red blood cell destruction and production need to be balanced. If there are too few erythrocytes in the blood this can lead to hypoxia, which means that there is not enough blood being supplied to the tissues, whereas if there are too many erythrocytes in the blood it makes it viscous and that begins to make the blood run slower (Marieb & Hoehn, 2014). Erythropoiesis is reliant on the levels of iron, lipids, carbohydrates and amino acids in the blood. Vitamin B12 is very important in this process as it is a necessary factor in the synthesis of DNA in regards to cell division (Marieb & Hoehn, 2014). Vitamin B12 deficiency occurs over a slow amount of time and prevents DNA synthesis and cell division occurring, therefore reducing the amount of erythrocytes in the blood (Grossman & Porth, 2013). This is a disorder called Pernicious Anaemia which occurs when the immune system doesnt recognise its own body cells and begins attacking the stomach wall. The cells that are located in this stomach wall are responsible for the production of a substance called; intrinsic factor which is vital for vitamin B12 to be absorbed by the intestinal cells. Without vitamin B12 in the stomach wall, erythrocytes can grow but they cant divide to produce more cells and instead of erythrocytes being produced macrocytes become the result (Marieb & Hoehn, 2014). Macrocytes are very large and possess an immature nucleus; they destruct themselves and have a weak outer membrane. Instead of having the trademark bio-concave shape of regular erythrocytes the macrocyte is oval shaped and has a short lifespan (Grossman & Porth, 2013). A concept map is provided below to show the normal homeostatic functioning of erythropoiesis and the abnormal effect that vitamin B12 deficiency has on this normal functioning. Normal Abnormal 1. Enough oxygen isnt being carried in the haemoglobin by the erythrocytes. 2. This stimulates the kidneys and liver to release the hormone EPO. 3. EPO then stimulates red bone marrow to create more erythrocytes. 4. Increased amount of erythrocytes. 5. Oxygen levels around the body return to normal. 4. Pernicious anaemia occurs; autoimmune disorder where antibodies attack cells in the gastric mucosa. 6. Large abnormal cells are the result. They have immature nuclei, weak membranes, they are oval shaped and have a short lifespan. 5. Intrinsic factor is produced in these gastric cells and so it is not present therefore preventing binding and absorption of vitamin B 12 which is vital for erythrocyte division. References Grossman, S., & Porth, C. (2013). Porth's pathophysiology: Concepts of altered health states. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. Huether, S. E., & McCance, K. L. (2013) Pathophysiology: the biologic base of disease in adults and children. Missouri: Elsevier. Marieb, E. N., & Hoehn, K. (2013). Human anatomy & physiology. Boston: Pearson. References Clark, A., & Cleland, J. (2013). Causes and treatment of oedema in patients with heart failure. Nature Reviews. Cardiology, 10(3), 156-170. doi: Hughes, R. (2013). Treatments to achieve fluid balance in heart failure. British Journal of Cardiac Nursing, 8(11), 537-540. Marieb, E. N., & Hoehn, K. N., (2014). Human Anatomy & Physiology. Boston, Unites States of America: Pearson. Show more