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Flashcards in test 3 urinalysis Deck (53):
0

List the functions that give the kidney the ability to clear waste products from blood and maintain essential water and electrolyte balance

Renal blood flow
Glomerular filtration
Tubular reabsorption
Tubular secretion

1

Which artery supplies blood to the kidney

Renal artery

2

Which arteriole allows blood to enter the capillaries of the nephron

Afferent arteriolar

3

What is the total blood flow through the kidney per minute

1200 mL/min

4

How many nephrons are in the kidney

1-1.5 million

5

List the three filtration mechanisms of the glomerulus

ENDOTHELIAL CELLS
BASEMENT MEMBRANE
PODOCYTES (FOOT CELLS)

6

Describe the difference between active and passive transport

Active transport is the movement of substance across a cell membrane by electrochemical energy
Passive transport is the movement by diffusion due to physical gradient

7

Describe how glomerular blood pressure is maintained

the juxtaglomerular apparatus increases and decreases the size of the afferent arteriolar by releasing a enzyme renin. it then converts to angiotesinogen to angiotesin I which is converted by an enzyme in the lungs to angiotensin II

8

Which part of the nephron does not reabsorb water

ASCENDING LIMB OF THE LOOP OF HENLE

9

List five substances that are actively transported back into the plasma

Glucose
Amino acids
Salts
Chloride
Water
Urea
Sodium

10

What does maximal reabsortive capacity mean

It's the maximum reabsorption for a solute by the renal tubules. The plasma has reached its maximum ability to hold that substance

11

What is the renal threshold for glucose

.160 to 180 mg/dL

12

How much water containing molecular weight substance is filtered by the kidney each minute

120 ml/min

13

What does the juxtaglomerular apparatus do and how does it do it

It helps to maintain the glomerular blood pressure by secretion of renin. it monitors the blood pressure and plasma sodium content. The renin reacts with the substrate angiotensinogen to produce the inert hormone angiotensin I. The

14

Which enzyme is produced by the juxtaglomerular apparatus

.renin

15

What is the specific gravity of the ultrafiltrate

1.010

16

Describe the renin-angiotensin-aldosterone system. How it works and what it does

it controls the regulation of the flow of blood to and within the glomerulus. It responds to changes in blood pressure and plasma sodium content that is monitored by the juxtaglomerular apparatus. Low blood pressure/low plasma sodium-> Renin secretion-> angiostensin I -> angiostesin II -> Vasconstriction, reabsorption of sodium in the proximal tubule, aldosterone secretion -> Sodium reabsorption in distal tubule, ADH ->Water reabsorption in collecting duct

17

What does aldosterone do

it stimulates the distal convoluted tubule to reabsorb sodium

19

Which parts of the glomerulus begin renal concentration

descending and ascending loops of Henle

19

What is the other name for antidiuretic hormone

Vasopressin

20

How is water removed in the descending loop of Henle

by osmosis

21

What state of the body controls ADH production

Hydration/dehydration

23

How does ADH control the reabsorption of water

it renders the walls of the distal tubule and collecting duct as permeable or impermeable.
increase in ADH-> increase in water reabsorption-> decreased urine volume
decrease in ADH -> decrease in water reabsorption -> increase in urine volume

24

What body substance controls sodium concentration

Aldosterone

25

What are the two major functions of tubular secretion

elimination of waste products not filtered by the glomerulus and regulation of the acid-base balance in the body through the secretion of hydrogen ions

25

What is the normal blood pH

7.4

26

What is the major site for removal of substances not filtered by the glomerulus

proximal convoluted tubule

27

Which buffering substance maintains blood pH

Bicarbonate

28

Describe the reabsorption of bicarbonate

Secretion of hydrogen ions by the renal tubular cells into the filtrate prevents the filtered bicarbonate from being excreted in the urine and causes the return of the bicarbonate ion to the plasma.

29

Describe the two mechanisms for excreting hydrogen ions

Hydrogen can bind with filtrated phosphate or it can combine with ammonia to make ammonium to be secreted

30

What is the difference between exogenous and endogenous test procedures

Exogenous is using a substance that hAs to be injected. Endogenous is using a substance that is made in the body at a steady rate to get the measurement such as creAtinine

31

Why is the insulin clearance test not used as a laboratory method to determine glomerular filtration rate

Because the person as to be hospitAlized to have an IV to steadily inject inulin

32

List three disadvantages of the creatinine clearance test

Heavy diet of meat during 24 hr collection can increase it
Some medications inhibit tubular secretion of creatinine
Some creatinine is secreted by the tubules, and secretion increases as blood levels rise

33

What is the formula for calculating creatinine clearance

Urine/volume (ml/min) Average surface area
-------------------------- X. -----------------------------
Plasma creatinine. Actual surface area

34

Why do we adjust creatinine clearance results for body size

Because more muscle means increase in creatinine levels

35

What are the normal creatinine clearance values in men and women

MEN: 107 –139 ml/min
WOMEN: 87 –107 ml/min

37

What is the difference between specific gravity and osmolarity

specific gravity is measure of density b/c it measures both number and size of particles
osmolarity only measures number of particles

38

What is the unit of measurement of osmolarity

milli-osmoles

39

Describe how a freezing point osmometer measures osmolarity

the freezing point is lowered as particles are added to solution.

40

what is the urinary system made up of?

2 Kidney
2 ureters
bladdder
urethra

41

Kidney processes

filtration
absorption
secretion

42

What remain in plasma

Proteins

43

where are amino acids and glucose reabsorbed

Proximal tubule

44

Where is sodium reabsorbed

Proximal tubule, loop of henle, and distal tubule

45

Parts of the nephron

Glomerulus (in Bowmans's capsule)
Proximal tubule
Loop of Henle
Distal tubule
Collecting duct

46

Blood flow direction

Afferent arteriole
peritubular capillaries
vasa recta
efferent arteriole

47

fluid in nephron is called what

protein free ultra filtrate of plasma

48

Angiostensin II functions

1. dilates afferent arteriole
2. constricts efferent arteriole
3. triggers release of aldosterone which increase the reabsorption of sodium in distal tubule and increase secretion of K+
4. triggers release of ADH

49

Where is water not reabsorbed

in the ascending loop of Henle

50

where is 65% of water reabsorbed

proximal tubule

51

Diabetes insipidus is what?

decreased production of ADH
polydypsia, polyuria

52

normal serum osmolarity

275 - 300 mOsm

53

normal urine osmolarity

50 - 1400 mOsm