Question

1. (3pts) How would you describe the condition of respiratory acidosis? What would be the response within the respiratory system to this condition? What would be the response of the urinary system to this condition?

2. (2pts) What are the major buffer systems in the body?

3. (3pts) As you’re probably aware the human body is approximately 60% (with large individual variation) water. How is water distributed within the body?  Be sure to address where it is found, what differences exist between location, and what forces act on water within the body to cause it to change location.

4. (4pts) What are the sources of water gain and loss in the body? What are they for sodium?  How are they connected?

5. (3pts) A person has a tumor in the adrenal cortex that continuously secretes large amounts of aldosterone. What effects does this have on the total amount of sodium and potassium in her body?

6. (3pts) Describe the detection of and response to low blood pressure in the body. Be sure to place this scenario into the context of a homeostatic mechanism, and clearly identify the structures that act as receptors, integrating center and effectors. You should identify specific mechanisms of reaction and the systems involved.

Answer 1

1. When body is not able to get rid of CO2. the levels of CO2 increases in our body , this high level of high CO2 is reflected as low pH in blood, this condition is known as respiratory acidosis. Response of lungs would be hyperventilation, which is increase in depth and rate of breathing, so that CO2 can be expelled out. Response of urinary system would be  increased urinary excretion of hydrogen ions and resorption of bicarbonate ion. This relatively slow process occurs over several days.

2. The three major buffer systems of our body are, phosphate buffer system and protein buffer system and the main buffer system, Carbonic acid bicarbonate buffer syste.

3.Total body water in an average human being, weighing about 70 kg is 40 litres to 45 litres. In human being it is about 65% of the body weight, The water in our body is distributed in two main location, in our cells which account for two thirds of total water (intracellular) and the remaining water is distributed out side the cell known as extracellular compartment, which acoounts for remaiining one third of total volume. This extracellular fluid compartment is further divided into, Plasma, Interstitial and transcellular fluid. Two main forces which control fluid movement are Hydrostatic pressure, which the force exerted by a fluid against a wall, causes movement of fluid between compartmen and Osmotic pressure, which is pressure produced by proteins in blood.

4. Water loss can primarily occur by  Urination. Excretion (feces) Perspiration (sweating). The main sources of water gain are drinking and ingesting fluids, such as water contained in food, and water produced as a byproduct of metabolic processes. Sodium has a property of retaining water, when there is high concentration of sodium in our body than more water will be retained by the body which in turn will increase the blood volume, when there is low dosium the reverse happens, the body retains less water this will decrease blood volume.

5. Aldosterone produced by the adrenal glans is the main hormone which regulates levels of sodium and potassium, when there is increased aldosterone it will act on kidney to reabsorb sodium and excrete potassium as a result sodium concentration increases and potassium level decreases.

6) When there is low blood pressure, mechanoreceptors located in the carotid sinus and aortic arch senses this pressure changes, they than cause the vasomotor center to activate sympathetic activity in heart and blood vessel, this increased sympathetic activity will cause heart rate to increase and vasoconstriction of blood vessels, this will in turn increase blood pressure so that normal blood pressure is attained.

In this case, Baroreceptos act as receptors, Vasomotor center which acts on Sympathetic nervous sytem is the Integrating center, and the blood vessel is the effectors.