Human Anatomy and Physiology System †Free Samples to Students

Question: Discuss about the Human Anatomy and Physiology System. Answer: Introduction: Plasma Membrane (or Cell Membrane) is the boundary that differentiate cells inner contents and its outer environments. Each cell of a multicellular organism contain certain amount of molecules or components inside them, therefore cellular membrane helps to maintain this amount by maintaining the balance between intracellular fluids and extra cellular fluids (Jenkins Tortora, 2013). The plasma is a unique and permeable structure that makes its appearance important at the boundary of each cell and enhances its activity in cellular functions such as exchange of gaseous materials and exchange of ions. The structure of the plasma membrane is known as the fluid mosaic model and according to this model the plasma membrane is a double layered lipid structure that have dispersed protein molecules through the structure. As the protein molecules are constantly changing and forms a mosaic structure within the membrane, this model is known as the fluid mosaic model (Stables Rankin, 2011). The components of this fluid mosaic structure are of two types, membrane lipids and membrane proteins. The lipid layer forms the basic structure of the membrane and within this structure, phospholipids (majorly), glycolipids, cholesterols and lipid rafts. The phospholipids are composed of a hydrophilic head and two hydrophobic tails, which is made up of fatty acid chains. This lipid layer forms a double layer so that each water loving side that is intracellular environment and extracellular environment can be connected (Stables Rankin, 2011). The benefit of this hydrophilic and hydrophobic combination is that despite of a fluid structure that moves constantly, the flip-flop action is prevented (Marieb Hoehn, 2016). Further the membrane proteins are inserted within the membrane structure and called transmembrane proteins and these proteins also contain hydrophilic and hydrophobic region and these proteins are divided in two sections. These sections are integral protein and peripheral proteins. These proteins forms channels and sections through which transportation of intracellular and extracellular liquids occur. Further, some proteins work as hormonal receptors for signal transduction process (Stables Rankin, 2011). The role of plasma membrane in oxygen transportation is highly effective and due to the semipermeable nature of plasma membrane the cell can transport oxygen and carbon di oxide across the cellular membrane ()Marieb Hoehn, 2016). This transportation occurs due to the concepts of diffusion, according to which, molecules moves from high concentration to low concentration, if divided by a semipermeable membrane. When the human body absorbs oxygen, the concentration of carbon di oxide is higher within the cell and low in the extracellular matrix, therefore the movement of CO2 from intracellular environment to extracellular environment occurs. Consequently, the concentration of oxygen increases outside the cell that helps to diffuse the oxygen into intracellular environment. Similarly, plasma membranes play viral role in exchange of ions across the cellular environment. The plasma membrane consists of a sodium potassium exchange pump that helps to pump sodium and potassium ions inside or outside the cell. In this case, despite of higher concentration of sodium ions outside the cell, the membrane does not allow transportation of these ions to pass through the membrane. Therefore, Sodium potassium pumps helps to diffuse these ions across the membrane (Marieb Hoehn, 2016). References Jenkins, G., Tortora, G. (2013).Anatomy and physiology, 3rd edn, pp. 12-87, Hoboken, NJ: John Wiley Sons. Marieb, E. N., Hoehn, K. (2016).10th Edn, pp, 34-78, Human anatomy physiology. Pearson Education. Stables, D., Rankin, J. (2011).Physiology in childbearing [electronic resource](3rd ed.), pp. 12-145,. Edinburgh: Baillie?re Tindall/Elsevier.