Case Study 1 Essays

Cells and molecules in the environment are constantly moving and changing, for cells to function properly there is a need for equilibrium to be met. The size of the cell and the solution outside of the cell affects the rate of diffusion and osmosis in the cell. Cells are constantly trying to reach an equilibrium with the molecules and substances around it, which is why there are such terms as: hypertonic, hypotonic and isotonic. The procedures allowed testing of whether or not surface area or volume increased diffusion and how different substance control diffusion. Cells are constantly moving to reach equilibrium through diffusion and osmosis.

The patient in “The Red Hat Hikers” scenario is suffering from hyponatremia. Hyponatremia is defined as a serum sodium level of less than 136mEq/L. Sodium is an electrolyte that is found predominately in the extracellular fluid, and it is the chief regulator of water in the body. Sodium is also important for muscle contraction, nerve impulses, acid-base balance and chemical reactions that occur inside the cell (McCance & Huether, 2014). Normal sodium levels in the body are maintained by the kidneys and the hormone aldosterone. Aldosterone is secreted by the adrenal cortex at the completion of the renin-angiotensin-aldosterone system, and it helps stimulate the proximal tubules of the kidneys to reabsorb sodium and water. The anti-diuretic hormone (ADH) also indirectly affects sodium levels because it regulates water balance in the body (McCance & Huether, 2014).

In this lab experiment, half our group observed and measured osmosis using dialysis tubes that were represented as the semipermeable membrane. It is permeable to water and other small molecules but is impermeable to larger molecules such as the sucrose solution used in each of the four beakers and tubing. The other half of our group observed the tonicity of sheep blood to determine whether the blood was isotonic, hypotonic, or hypertonic. The 85 g/dL of NaCl solution was the ideal isotonic number in relation to the sheep blood cells as well as a reference to the other observations of the solutions.

Osmosis is described in one of three ways when comparing more than one solution. The cell’s external and internal environment helps determine tonicity, which is defined as how the cell reacts to its environment. When the cell’s environment is equal in osmolarity to itself and there is no change, it is considered an isotonic solution. When the environment has a higher osmolarity, shrinkage occurs and it is considered a hypertonic solution. When the environment has a lower osmolarity, swellings occurs and it is considered hypotonic.

Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.

Marathon runners put their body through great physical challenges, but in order to prevent physiologic harm, the normal fluid and electrolyte status of an adult marathon runner is important to know. For a normal adult male, the total body water (TBW) in relation to body weight is about 60%, and in females, the percentage is 50 (McCance, 2010). About two thirds of the TBW resides in the intracellular fluid (ICF), in other words blood, and the rest of the TBW remains in the extracellular fluid (ECF), interstitial and intravascular (McCance, 2010). Depending on the age, sex, percent of body fat and exercise status, the TBW will vary among individuals, which is very important in considering the manifestations of fluid replacement in marathon running (Duvillard et al, 2004).

The body needs to maintain equilibrium to function properly in everyday life. The most important substance it must regulate is water; water is everywhere in our body and its balance is essential for proper body function.

The concentration of dissolved substances is greater in the extracellular fluid than in the cytoplasm. Hypertonic Solution Concentration of dissolved substances (solute) Concentration of water (solvent) What happens to an animal cells? Inside the cell Less Greater Outside the cell Greater Less Membrane

What limits the speed and stamina of most endurance athletes is the ability of their heart and lungs to deliver oxygen at a steady rate

For D2, I am going to analyse the influence of water balance dysfunctions on the body.

B. In biological systems if a cell is placed into a salt solution in which the salt concentration in thesolution is lower than in the cell, the solution is said to be hypotonic. Water will move from the solution into the cell, causing lysis of the cell. In other words, the cell will expand to the point where it bursts.

2. A hypertonic solution will cause the cell to shrink because more particles are in the solution and not in the cell.

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 3: Simulating Osmotic Pressure Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Which of the following is true of osmosis? You correctly answered: c. It is a type of diffusion. 2. Which of the following occurs when a hypertonic solution is added to cells? You correctly answered: d. The cells shrink. 3. The variable that affects osmotic pressure is You correctly answered: a. the concentration of nondiffusing solutes. 4. The net movement of water would be into the cell in a You correctly answered: b. hypotonic solution.

Homeostasis is the ability to preserve a dynamic stable internal environment factor and to set the correct operative mechanisms to restore the factor back to the optimum level. There are many types of stable internal environment factors that the body has to maintain in order to function correctly that includes thermoregulation, osmotic control and blood sugar regulation. How the athlete’s body manages to keep a stable concentration of glucose in the blood in the coast to coast event is the subject of this report.

Metabolic reactions within the cells often produce a huge excess of H+. Lack of any mechanism for its excretion would lead H+ levels in body fluids rise quickly to the lethal levels (Tortora, Grabowski 2006, p.1001); therefore the homeostasis of the right H+ levels is