renal

Question 1

name the 8 functions of the renal system

Answer 1

1. maintenance of homeostasis formation of urine
2. excretion of waste and toxins
3. regulation of electrolyte balance
4. regulation of fluid balance
5. regulation of acid/base balance
6. production of renin- control blood pressure
7. produce erythropoietin
   8.metabolise vitamin D (convert from inactive-active)

Question 2

how many nephrons are present per kidney

Answer 2

1 million

Question 3

what are the 6 structural components of the nephron

Answer 3

1. glomerulus, 2. Bowmans (glomerula) capsule, 3. proximal convoluted tubule, 4. loop of henle, 5. distal convoluted tubule, 6. collecting duct

Question 4

what are the 2 segments of the loop of henle

Answer 4

thin segment- descending and thick segment- ascending

Question 5

what are the 3 stages of formation of urine

Answer 5

1. filtration 2. reabsorption 3. secretion

Question 6

where is the filtration membrane located

Answer 6

glomerulus capsule

Question 7

name 2 stages of filtration

Answer 7

1. fenestrations (pores) allow small molecules through 2.filtration membrane helps retain large molecules, membrane is -ve charged repelling -ve molecules and allowing +ve molecules through

Question 8

what is the rate of kidney filtration called

Answer 8

glomerular filtration rate (GFR)

Question 9

name 3 molecules found in filtrate

Answer 9

glucose, amino acid, wastes, vitamins, electrolytes, nutrients, water

Question 10

what is the approximate GFR

Answer 10

125ml/min

Question 11

what is the measurement of filtrate produced a day

Answer 11

180 liters but only 1.5 litres of urine a day, therefore majority is reabsorbed by body

Question 12

what is the equation for net filtration

Answer 12

outgoing-ingoing=net filtration

Question 13

what is the definition of reabsorption

Answer 13

return of useful substances and water from filtrate to blood

Question 14

where does reabsorption begin

Answer 14

PCT- proximal convoluted tubule

Question 15

what does Tm stand for

Answer 15

transport maximum- maximum amount of substance that can be reabsorbed

Question 16

what condition occurs if glucose exceeds its Tm

Answer 16

it is lost in urine- glycosuria- identifying diabetes

Question 17

how does ADH affect reabsorption

Answer 17

affects permeability of collecting duct for water, helping to increase reabsorption or loss

Question 18

which ion is actively reabsorbed

Answer 18

Na+

Question 19

after active reabsorption of Na+ which molecules follow passively

Answer 19

h2o, ions and nutrients

Question 20

define secretion

Answer 20

active removal of unwanted substances/wastes from the blood into filtrate

Question 21

where does secretion occur

Answer 21

all along tubule

Question 22

what is a major importance of secretion

Answer 22

help maintain pH

Question 23

name 3 substances to secrete

Answer 23

H+, K+, ammonium, creatine, drugs

Question 24

what are the percentage compositions of urine

Answer 24

95% water, 5% solutes

Question 25

name as many components of urine as possible

Answer 25

1. water, 2.urea(breakdown of amino acids), 3.sodium, 4.pottasium, 5.phosphate, 6.creatine(from metabolism of muscle tissue), 7.uric acid(from metabolism of nucleic acid)

Question 26

why is urine measured in clinical setting

Answer 26

to indicate level of renal function

Question 27

what is 1 Osmol

Answer 27

1 mol of particle per Kg of H2O

Question 28

what does mOsm stand for and why is it used

Answer 28

milliosmols- how body fluids are expressed due to much smaller volume

Question 29

what is the urine mOsm measurement at top of descending limb, what is measurement at bottom of descending limb and what is measurement at top of ascending limb

Answer 29

top of descending= 300mOsm
bottom of descending = 1200mOsm
top of ascending = 325mOsm

Question 30

what does ADH stand for

Answer 30

anti-diuretic hormone

Question 31

how does increase in ADH and decrease in ADH affect volume of urine

Answer 31

increased ADH= greater reabsorption, less urine
decreased ADH= less reabsorption, more urine

Question 32

how does the renal system maintain pH

Answer 32

if pH falls then increase in H+ ions into urine, in tubules the H+binds with buffer and excreted in urine as ammonia.
opposite if alkotic

Question 33

where is erythropoietin produced

Answer 33

by kidneys

Question 34

what does EPO stand for

Answer 34

erythropoietin