The Kidney and Renal Function

Question 1

Kidney Disease can be:

Answer 1

• chronic
• acute and present with life threatening
  emergencies

Question 2

Functions of the urinary tract (2):

Answer 2

1) Excretion: removal of organic waste
products
2) Elimination: discharge of waste products
into the environment

Question 3

Homeostatic functions of the kidney (2):

Answer 3

• regulation of water and electrolyte balance
• regulation of acid base balance

Question 4

Excretory functions of the kidney (2):

Answer 4

• excretion of drugs and their metabolites
• excretion of endogenous waste products

Question 5

Regulatory functions of the kidney (1):

Answer 5

• production of hormones: erythropoietin,
  renin, prostaglandins, active vit D

Question 6

Erythropoeitin function

Answer 6

stimulates bone marrow to create RBCs

Question 7

Manifestations of kidney disease:

Answer 7

Question 8

The Kidneys

Answer 8

Question 9

Two major layers of the kidney:

Answer 9

1) Cortex
2) Medulla

Question 10

Cortex of kidney (2):

Answer 10

• outer region
• contains glomerulus and convoluted
  tubules

Question 11

Medulla of Kidney (3):

Answer 11

• inner region of kidney
• arranged into pyramid like structures
• consists of the bulk of nephron structure

Question 12

What is the functional unit of the kidney?

Answer 12

• nephron
• responsible for urine formation/
  composition

Question 13

Early stages of chronic kidney disease you can lose upto

Answer 13

50% of nephrons

Question 14

Five distinct sections of nephron:

Answer 14

• Glomerulus
• Proximal Convoluted Tubule
• Loop of Henle
• Distal Convolute Tubule
• Collecting Duct

Question 15

Nephron

Answer 15

Question 16

Nephron functions

Answer 16

Question 17

Renal Blood Flow (normally)

Answer 17

1-1.25L/min

Question 18

Glomerular Filtration Rate (normally)

Answer 18

100-125ml/min (150-200L/day)

Question 19

Total no. nephrons: 2.5 million:
Cortical:
Juxtaglomerular:

Answer 19

Cortical: 2.1 million
Juxtaglomerular: 0.4 million

Question 20

Tubular fluid enters the collecting duct

Answer 20

• deep in the inner medulla of kidney
• tubular fluid exits at the tip of the renal
  pyramid

Question 21

A site of drug-induced nephrotoxicity is

Answer 21

the renal papilla

Question 22

Cortical nephrons:

Answer 22

• 70-80% of all nephrons in a kidney
• located in the cortex
• short loop of Henle into the medulla

Question 23

Juxtaglomerular Nephrons:

Answer 23

• 20-30%
• situated closer to the medulla
• loop of henle extends deep into renal
  pyramids

Question 24

Modification of urine occurs in which part of the nephron

Answer 24

• the distal collecting tubule
• the collecting duct

Question 25

The nephron

Answer 25

Question 26

Juxtaglomerular Apparatues: - is? - produces? - location? - function - components (3) c

Answer 26

- specialised region associated with the nephron, but separate from it - produces and secretes renin - located between the thick ascending limb and afferent arteriole - measures and identifies changes in blood pressure and regulation of renin secretion Components (3): - Macula densa - Juxtaglomerular cells - Extragomerular mesangial cells

Question 28

The Renal Corpuscle

Answer 28

Question 29

Clinical Importance of Nephrons:

Answer 29

- Diseases of the nephron affect the glomeruli or tubules

Question 30

Glomerular Disease(3):

Answer 30

- Diabetic nephropathy - Glomerulonephritis - IgA Nephropathy

Question 31

Renal Tubular Diseases (3):

Answer 31

- acute tubular necrosis - Glomerulonephritis - IgA Nephropathy

Question 32

Blood Suppky to the nephron

Answer 32

Question 33

What % of cardiac output does the kidneys receive and 90% of this supplies

Answer 33

- 20-25% of cardiac output - 90% of this supplies the renal cortex maintaining highly active tubular cells

Question 34

Order of vessels for nephron blood supply ***

Answer 34

- main renal artery - segmental - interlobar - arcuate - interlobular - afferent arteriole into golmerulus - efferent arteriole - peri-tubular capillaries - vasa recta - renal vein

Question 35

Blood Supply to the Nephrons

Answer 35

Question 36

Cortical nephrons major role

Answer 36

regulatory and excretory function

Question 37

Juxtaglomerular nephrons major role

Answer 37

in concentrating or diluting urine

Question 38

Juxtaglomerular nephrons have a long loop of henle that penetrates deep into the medulla. true or False?

Answer 38

True

Question 39

Cortical nephrons have a glomerulus and bowmans capsule. True or False?

Answer 39

True

Question 40

Juxtaglomerular nephrons have a glomerulus and bowmans capsule. True or False?

Answer 40

True

Question 41

Cortical nephrons have vasa recta. True or False?

Answer 41

False Juxtaglomerular nephrons have large vasa recta

Question 42

Sympathetic nerve supply to the kidney:

Answer 42

Sympathetic: coeliac ganglion and sympathetic chain - supplies arteries - reduces blood supply to kidney during stress, increases renin secretion = associated with hypertension

Question 43

Parasympathetic nerve supply to the kidney:

Answer 43

- efferent from vagus nerve (hilum) - controls tone of efferent arterioles - may modify GFR and renal blood flow

Question 44

The Glomerulus

Answer 44

Question 45

1 capillary forms how many glomerular loops

Answer 45

40

Question 46

Interstitium of glomerulus

Answer 46

site of erythropoeitin and prostaglandin production

Question 47

What component of the juxtaglomerular apparatus releases renin?

Answer 47

Macula Densa

Question 48

Glycocalyx

Answer 48

layer of negatively charged proteoglycansand glycosaminoglycans coats the luminal surface of endothelial cells and the opening of fenestra

Question 49

Permeability in glomerular capillaries is higher than other capillaries. True or False?

Answer 49

True

Question 50

Glomerular Filtration Barrier

Answer 50

Question 51

Glomerular Filtration is dependent on (2):

Answer 51

- blood pressure - renal blood flow

Question 52

Glomerular filtrate has to pass through:

Answer 52

- pores in glomerular capillary endothelium - the basement membrane of bowman's capsule (contractile mesangial cells) - epithelial cells of bowmans capsules (PODOCYTES) via filtration slits into capsular space

Question 53

mesangial cells in the center of the glomerulus affect on GFR

Answer 53

- phagocytic clearing Ag/Ab complexes and contract due to angiontensin II and ADH reducing GFR by reducing filtration surface area

Question 54

Where does secretion occur through glomerular filtration

Answer 54

Question 55

ultrafiltration definition

Answer 55

solution moves by pressure gradient

Question 56

GFR changes when systemic BP changes. True or False?

Answer 56

False GFR generally remains constant even when systemic BP changes involves autoregulation of renal blood flow

Question 57

Three major functions of the nephron:

Answer 57

- filtration: blood to produce a filtrate - reabsorption: H2O, ions, organic nutrients - secretion: waste products into tubular fluid

Question 58

Transcellular transport

Answer 58

- passive or active - can be secondary to active transport

Question 59

Paracellular transport

Answer 59

movement driven by concentration, osmotic or electrical gradients

Question 60

Paracellular re-absorption occurs through

Answer 60

tight junctions

Question 61

Processes of the nephron

Answer 61

Question 62

Tubular re-absorption

Answer 62

- 99% filtered water, electrolytes and nutrients re-absorbed into blood - some solutes re-absorbed either active, passive, secondary

Question 63

tubular Secretion:

Answer 63

- some endogenous substances and drugs not filtered at glomerulus due to size/protein binding - specialised pumps in PCT transport compound in plasma to nephron - for organic acids or drugs - for organic bases or drugs