AUBF LEC

Question 1

3 processes of urine formation

Answer 1

Glomerular filtration
Tubular reabsorption
Tubular secretion

Question 2

What enzyme converts ANGIOTENSIN I TO ANGIOTENSIN II

Answer 2

Angiotensin converting enzyme

Question 3

Secretion of aldosterone stimulates?

Answer 3

SODIUM REABSORPTION

Question 4

Secretion of ADH stimulates?

Answer 4

WATER REABSORPTION

Question 5

Permeable to water and low molecular weight solutes while it excludes proteins larger than albumin

Answer 5

Glomerular filtration barrier

Question 6

The ____ serves as a non selective filter of plasma substances with molecular weights less than 70, 000

Answer 6

Glomerulus

Question 7

3 glomerular filtration barrier cellular layers;

Answer 7

Capillary wall membrane
Basement membrane
Visceral epithelium of the bowman’s capsule

Question 8

Specific gravity of ultrafiltrate

Answer 8

1.010

Question 9

Glomerular filtration rate:

Answer 9

90- 120 ml/minute

Question 10

Final urine volume of:

Answer 10

600- 1800 ml

Question 11

Results from the reduction of the size (diameter of lumen) of efferent arterioles snd glomerular capillaries
- forces fluid to the bowman’s space at a pressure of 55mmHg

Answer 11

Hydrostatic pressure

Question 12

This type of pressure is exerted by the fluid in the bow,an’s space that opposes filtration by 15 mmhg

Answer 12

Capsular hydrostatic pressure

Question 13

This type of pressure is exerted by unflitered proteins in the glomerular capillaries that also opposes filtration at a magnitude of 30 mmHg

Answer 13

Blood colloid osmotic pressure/ oncotic pressure

Question 14

This pressure contains the remaining 10 mmhg outcome of these pressure differences that is favorable in the formation of the plasma ultrafiltrate

Answer 14

Net filtration pressure

Question 15

99% (majority of the plasma ultrafiltrate that enters the renal tubules are reabsorbed)

Answer 15

Tubular reabsorption

Question 16

This transport requires no energy and allow movement of solutes along concentration gradient which is from high solute concentration to a low solute concentration

Answer 16

PASSIVE TRANSPORT

Question 17

This transport requires energy to move solutes as it moves against a concentration gradient (low solute to high)

Answer 17

Active transport

Question 18

How many percent of the ultra-filtrate is reabsorbed in the proximal convoluted tubules

Answer 18

80%

Question 19

TRUE OR FALSE: Sodium and chloride are partly reabsorbed while glucose and proteins are almost completely reabsorbed

Answer 19

True

Question 20

As the amount of solute increases, the rate of reabsorption increases until the maximum rate of reabsorption is reached

Answer 20

MAXIMAL TUBULAR REABSORPTIVE CAPACITY (Tm)

Question 21

Solutes that exhibit Tm includes?

Answer 21

Glucose
Amino acids
Proteins
Phosphates
Sulfates
Uric acid

Question 22

Refers to the concentration of solute in plasma ar which the maximal tubular reabsorptive capacity of the tubules has been exceeded

Answer 22

Renal threshold

Question 23

Renal threshold of glucose and its tm?

Answer 23

160-180 mg/dl
Tm: 350 mg/min

Question 24

Water is reabsorbed throughout the nephron via?

Answer 24

OSMOSIS

Question 25

The tubular epithelium in the ____ is selectively impermeable to water despite the presence of an osmotic gradient between the tubular lumen and medullary interstitium due to the histologic characteristics of its epithelium

Answer 25

Thin ascending limb of the loops of henle

Question 26

Blood ph is maintained by the:

Answer 26

buffering system, respiratory system and kidneys

Question 27

In cases of alkalosis, hydrogen ions are? And incases of acidosis?

Answer 27

Alkalosis= hydrogen ions are retained Acidosis= hydrogen ions are secreted

Question 28

The osmotic gradient of the renal medulla makes it the only tissue in the body that is ? With respect to normal plasma

Answer 28

HYPERTONIC

Question 29

A polymer fructose, an extremely stable substance that is neither reabsorbed, nor secreted by the tubules

Answer 29

INULIN

Question 30

3 mechanism by which the tubules participate in maintaining blood ph

Answer 30

1. Secretin of H ion in the proximal tubular lumen that reacts with HCO3 to form carbonic acid -The HCO3 present in the tubular cells, diffuses to the interstitial fluid and peritubular capillaries to resupply the blood buffer system 2. Secretory mechanism that involves neutral phosphate salts present in the tubular lumen Phosphoric acid + ( forms monosodium phosphate or mononasic phosphate 3. Depends on ammonia secretion and subsequent exchange of sodium for ammonium ions

Question 31

This actively happens in the loops of henle

Answer 31

Countercurrent multiplier mechanism

Question 32

This passively happens and involves the vasa recta

Answer 32

Countercurrent exchange mechanism

Question 33

Water is passively reabsorbed in the descending loop of henle with solutes not being reabsorbed with t he exception of ure

Answer 33

Countercurrent multipliers mechanism