7. Physiology of the Urinary System Part III

Question 1

Diuretics (3)

Answer 1

1) Decrease Na+ reabsorption
2) Less water is reabsorbed from the filtrate
3) Example: furosemide (“water pill”) is used to treat edema

Question 2

Some types of diuretics (3)

Answer 2

1) Caffeine:
a) Renal tubules increase in diameter
b) Increases amount of flow through the tubules

2) Alcohol:
a) Inhibits the release of ADH
b) ADH cannot insert water channels into the tubules
c) Less water reabsorption

3) Actions of other diuretics:
a) Cause greater flow of filtrate in the nephron
b ) Allows less time for ions to be removed from the filtrate

Question 3

Cardiovascular Baroreceptors (3)

Answer 3

1) Regulate blood volume

2) Mechanoreceptors located in the aortic arch and carotid sinus arteries

3) Detects the amount of stretch found in the vessels
a) More stretch = higher blood volume = higher blood pressure

Question 4

Cardiovascular Baroreceptors mechanism (3)

Answer 4

1) Cranial nerves relay information to the medulla

2) Medulla continuously monitors blood volume to maintain blood pressure

3) If blood volume rises:
a) Baroreceptors inhibit sympathetic nervous system signals to the kidney
b) Dilates the afferent arterioles
c) Increases filtration rate
d) Increases output of water and Na+
e) Quickly reduces blood volume to normalize pressure

Question 5

Normal urine (2)

Answer 5

1) Color
a) Pale to deep yellow
b) Yellow is from presence of urochrome

2) Urochrome - pigment derived from the metabolic breakdown of hemoglobin

Question 6

Abnormal urine (2)

Answer 6

1) Various colors
a) Drugs
b) Food (dark beets, rhubarb)
c) Presence of bile pigments
d) Blood in urine

2) Cloudy
a) Presence of pus - dead white blood cells
b) May indicate a UTI

Question 7

Urine odor (2)

Answer 7

1) Normal
a) Slightly aromatic
b) Develops stinging ammonia odor upon standing due to bacterial breakdown of urea

2) Abnormal
a) Asparagus and some drugs
b) Diseases (diabetes mellitus) makes a fruity smell from acetone`

Question 8

Urine pH (3)

Answer 8

1) Normal - 4.5 to 8

2) Diet high in citrus, vegetable, diary
a) Higher pH (more basic)

3) Diet high in proteins
b) Lower pH (more acidic)

Question 9

Urine density

Answer 9

Normal
a) Higher than water (1.00) because it contains dissolved solutes
b) Range - 1.003-1.035

Question 10

Normal urine contents (2)

Answer 10

1) 95% water

2) 5% solutes
a) Urea: most abundant (2%)
b) Nitrogenous wastes: uric acid, creatinine, ammonia
c) Other solutes: sodium, potassium, phosphate, chloride, etc.