Lecture 26

Question 2

What factors influence urine characteristics?

Answer 2

Water intake, exercise, temperature, nutrient intake, hydration status.

Question 3

Normal daily urine volume?

Answer 3

1–2 L/day.

Question 4

Minimum urine output needed to remove wastes?

Answer 4

~500 mL/day.

Question 5

Oliguria definition?

Answer 5

Urine output below 500 mL/day.

Question 6

Anuria definition?

Answer 6

Near absence of urine production.

Question 7

Polyuria definition?

Answer 7

Excessive urine production.

Question 8

Normal urine pH range?

Answer 8

4.5 to 8.0.

Question 9

Factors lowering urine pH?

Answer 9

High meat diet.

Question 10

Factors raising urine pH?

Answer 10

Citrus fruits, vegetables, dairy.

Question 11

Abnormal urine pH risks?

Answer 11

Kidney stones or osteomalacia.

Question 12

What is specific gravity?

Answer 12

Urine density relative to water; reflects osmolality.

Question 13

Normal specific gravity range?

Answer 13

1.010–1.030.

Question 14

Leukocytes in urine indicate?

Answer 14

Urinary tract infection.

Question 15

Protein in urine indicates?

Answer 15

Glomerular damage (if above trace).

Question 16

Ketones in urine indicate?

Answer 16

Fat metabolism due to low carbs or diabetes.

Question 17

Why ketonuria in diabetes?

Answer 17

Low insulin → glucose not used → fat metabolism.

Question 18

Urea production source?

Answer 18

Liver converts ammonia to urea.

Question 19

Normal urine appearance?

Answer 19

Yellow, clear, aromatic.

Question 20

Role of kidney in vitamin D activation?

Answer 20

Converts calcidiol → calcitriol.

Question 21

Role of calcitriol?

Answer 21

Increases calcium absorption in digestive tract.

Question 22

Importance of calcium?

Answer 22

Bone health, muscle contraction, neurotransmission, clotting.

Question 23

Kidney’s role in EPO production?

Answer 23

Produces ~85% of erythropoietin.

Question 24

Effect of kidney failure on EPO?

Answer 24

Leads to anemia.

Question 25

How kidney failure affects blood pressure?

Answer 25

Loss of Na+/water balance → hypo- or hypertension.

Question 26

Effect of diabetes on renal water control?

Answer 26

Glucose causes osmotic diuresis → dehydration.

Question 27

Why is pH homeostasis important?

Answer 27

Enzymes require narrow pH ranges.

Question 28

Systems maintaining pH balance?

Answer 28

Kidneys and lungs.

Question 29

Water percentage in adults?

Answer 29

~55% women, ~60% men.

Question 30

Major fluid compartments?

Answer 30

Intracellular (2/3) and extracellular (1/3).

Question 31

Interstitial fluid function?

Answer 31

Transports gases, nutrients, wastes.

Question 32

Blood plasma proportion of ECF?

Answer 32

20% of extracellular fluid.

Question 33

Major extracellular ions?

Answer 33

Na+ and Cl−.

Question 34

Major intracellular ions?

Answer 34

K+ and HPO₄²⁻.

Question 35

Pressures governing fluid movement?

Answer 35

Hydrostatic and osmotic pressure.

Question 36

Typical daily water intake?

Answer 36

~2.5 L.

Question 37

Sources of metabolic water?

Answer 37

~300 mL from aerobic respiration.

Question 38

Typical daily water loss?

Answer 38

~2.5 L (urine, sweat, breathing).

Question 39

Plasma osmolality definition?

Answer 39

Ratio of solutes to water; indicates hydration.

Question 40

Location of osmoreceptors?

Answer 40

Hypothalamus.

Question 41

High plasma osmolality triggers?

Answer 41

Thirst and ADH release.

Question 42

ADH function?

Answer 42

Increases water reabsorption via aquaporins.

Question 43

Why dehydration causes dry mouth?

Answer 43

Reduced watery saliva due to sympathetic signals.

Question 44

Can kidneys replace lost water?

Answer 44

No, they only conserve water.

Question 45

What triggers baroreceptors?

Answer 45

Low blood pressure or volume.

Question 46

Two responses to low blood volume?

Answer 46

↑HR/vasoconstriction + RAAS activation.

Question 47

RAAS effects?

Answer 47

Angiotensin II increases thirst and aldosterone.

Question 48

Aldosterone function?

Answer 48

Increases Na+ reabsorption → water follows.