HW1.1

=Homework 1=

HW1 Problem 1

Important Information
 * [Na+] => Sodium Ion Concentration
 * Q ra => Flow rate of blood in single renal artery
 * Table 1.12
 * H => Hematocrit - Amount, by Volume, of Red Blood Cells (RBCs) in Serum

Part A

//Main Focus: The main point of this problem is to get you to learn how to work with dimensions. You also need to realize that the filtration percent is a ratio of filtration rate to total flow rate.//

F' = Filtration rate.

Fraction of water FILTERED across Glomerulus = F'/Q water

Q water = 2 kidneys * 1.25 L/(min*kidney) * (1 - H)

F' = 9.1% for men F' = 8.3% for women

**Note: The flow rate given is the flow rate of blood in a single Renal Artery, there are two kidneys, therefore you need to multiply the flow rate by 2.
 * Important assumption: Assume (for this problem) that the serum consists only of the RBCs and water.

Part B

//Main Focus: In this problem you need to worry about the amount of fluid that you are losing to the urine. This can be thought of as a conservation of mass problem. This problem also involves a unit conversion similar to the one in// Part A.

Qra = Qrv + Qexc

Qrv = Flow rate in renal vein Qexc = Flow rate of excretion

Qrv = Qra - Qexc Assume: Although other things are being excreted, none of them matter as much as the excretion of water, which would directly affect the flow rate by resulting in a loss of fluid in the system.

//==>// Qrv,water = Qra,water - Qexc,water

Answer: 1.249 L/min

Part C

//Main Focus: You need to know the definition of a Molarity. You also need to realize that some of the sodium is being lost to excretion. You also need to remember to convert your units.//

[Na+] - concentration of Sodium M' = molar flow rate

[Na+],rv = (M'ra,sodium - M'exc,sodium)/Qrv

M'ra,sodium = Qra*[Na+],ra

Answer = 150.037 mmol/L = 150.037 mM

include component="comments" page="page:HW1.1" limit="10"