RENAL PHYSIOLOGY

Question 1

RENAL FUNCTIONS

Answer 1

a. renal blood flow
b. glomerular filtration
c. tubular reabsorption
d. tubular secretion
e. Erythropoietin production

Question 2

How many nephrons each kidney?

Answer 2

1-1.5 millions

Question 3

Basic structural unit of the kidney

Answer 3

NEPHRON

Question 4

Two types of nephron and their functions

Answer 4

1) Cortical nephrons - removal of waste and reabsorption of nutrients; 85% of nephron

2) Juxtamedullary nephrons - concentration of urine; have longer hoops of Henle; 15% of nephron

Question 5

Blood flow in KIDNEY

Answer 5

Afferent arteriole –> efferent arteriole –> peritubular capillaries –> vasa recta

Question 6

Kidney receives how much/many of blood?

Answer 6

20-25% of blood

Question 7

This surrounds the proximal and distal convoluted tubule

Answer 7

Peritubular capillaries

Question 8

Vasa recta is located at?

Answer 8

Located at the adjacent of ascending and descending loop of Henle

Question 9

Where loop of Henle is located

Answer 9

Medulla

Question 10

This is where urine formation begins

Answer 10

GLOMERULUS

Question 11

How many coils of capillary lobes does glomerulus have?

Answer 11

8

Question 12

Forms the beginning of the renal tubule

Answer 12

Bowman’s capsule

Question 13

TRUE OR FALSE
Glomerular filtration barriers are SELECTIVE filter

Answer 13

False; it is non-selective

Question 14

What are the three glomerular filtration barriers?

Answer 14

1) Capillary wall membrane
2) Basement membrane
3) Visceral epithelium of Bowman’s capsule

Question 15

In the glomerulus, this are foot like processes that has _____________ that repels negative charged protein

Answer 15

PODOCYTES; Shield of negativity

Question 16

Specific gravity of plasma filtrate

Answer 16

1.010

Question 17

Factors influencing glomerular filtration

Answer 17

a) Structure of capillary walls and Bowman’s capsule
b) Hydrostatic and oncotic pressure
c) Feedback mechanism of RAAS (Renin-Angiotensin-Aldosterone System)

Question 18

Explain the RAAS; how does it work?

Answer 18

Low Na+ –> Decrease H2O retention –> Decrease Blood volume –> Decrease BP –> Macula densa sense changes in BP
–> Juxtaglomerular cells produce and secrete RENIN (enzyme and Hormone) -> Renin + Angiotensinogen –>
Angiotensin I + Angiotensin converting enzyme (In the alveoli of the lungs) –> Angiotensin II, which will:

Angiotensin 2 will
- Dilate afferent arteriole and constrict efferent arteriole
- Triggers the release of ALDOSTERONE and ADH (Antidiuretic hormone).

Question 19

What is the role of aldosterone and ADH in RAAS?

Answer 19

ALDOSTERONE - For retention/reabsorption of sodium
ADH - Retention of water

Question 20

GFR: <15 mL/min
what is the stage and description that is according to the systematic classification of chronic kidney disease?

Answer 20

Stage 5; kidney failure

Question 21

Proximal convoluted tubules has columnar cells with ____________ border

Answer 21

Brush border

Question 22

PCT reabsorbs ….

Answer 22

Bicarbonate
Urea
Uric acid
Water
Glucose
Salt
Calcium
Phosphate
Protein

Question 23

This mechanism uses ATP, movement of substance against a gradient

Answer 23

active transport

Question 24

In active transport, where does Na+ is reabsorbed?

Answer 24

PCT & DCT

Question 25

In active transport, give the other substances and their location where they are reabsorbed

Answer 25

Glucose, amino acid, NaCl - PCT Chloride - ascending loop of Henle

Question 26

Movement of substance as a result of differences in concentration

Answer 26

passive transport

Question 27

TRUE OR FALSE H2O is reabsorbed in all parts except descending loop of Henle

Answer 27

FALSE it should be ascending loop of Henle

Question 28

What is the glucose renal threshold and its average?

Answer 28

160-180 mg/dL ave: 170 mg/dL

Question 29

Give the sodium threshold

Answer 29

120 mmol/L

Question 30

Give the threshold substances

Answer 30

NaCl amino acids creatine ascorbic acid

Question 31

Tubular concentration begins in the

Answer 31

descending and ascending loop of Henle

Question 32

Maintains the osmotic gradient of the medulla

Answer 32

Countercurrent mechanism

Question 33

Distal convoluted tubule secretes this substance to make the urine acid

Answer 33

NH3 Ammonia

Question 34

This is where the final adjustment of the urinary composition

Answer 34

Distal convoluted tubule

Question 35

It regulates the final urine concentration by controlling tubular permeability

Answer 35

Antidiuretic hormone/ADH

Question 36

Explain what happens when there is LOW and HIGH BODY HYDRATION

Answer 36

Low body hydration --> Present ADH - CD is permeable to water --> low urine volume (Oliguria) High body hydration --> Absent ADH - CD is impermeable to water --> high urine volume (Polyuria)

Question 37

Factors that suppresses Antidiuretic hormone

Answer 37

Caffeine Alcohol Diuretics

Question 38

In nephrogenic diabetes insipidus, there is

Answer 38

There is ADH resistance

Question 39

In neurogenic diabetes insipidus, there is

Answer 39

There is LOW ADH