diuretics

Question 1

what are the functions of the kidneys?

Answer 1

• regulation of H2O and inorganic ion balance
• removal of metabolic waste products from blood and excretion in urine
• removal of foreign chemicals in the blood and excretion in urine
• gluconeogenisis
• endocrine functions (renin, eythropoietin and aldosterone)

Question 2

where are the adrenal glands found?

Answer 2

theyre found at the top of the kidneys

Question 3

what is the role of the adrenal glands?

Answer 3

theyre responsible for secretion of a number of important hormones

Question 4

what is each adrenal gland made up of?

Answer 4

theyre each comprised of two endocrine components, a medulla (the inner part) that makes up 20% of the gland and a cortex (the outer part) that makes up the other 80%

Question 5

what parts make up the cortex of the adrenal gland?

Answer 5

zona glomerulosa
zona fasciculata
zona reticularis

Question 6

what does the zona glomerulosa secrete?

Answer 6

mineralcorticoids (aldosterone)
Na+, K+ and water homeostasis

Question 7

what does the zona fasciculata secrete?

Answer 7

glucocorticoids (cortisol)
glucosa homeostasis and many others

Question 8

what does the reticularis secrete?

Answer 8

sex steroids (androgens)

Question 9

what does the medulla secrete?

Answer 9

catecholamines such as adrenaline, noradrenaline and dopamine

Question 10

where does glomerular filtrate drain?

Answer 10

it drains into the bowman’s space then into the proximal convoluted tubule

Question 11

what do endothelium pores allow through?

Answer 11

it allows through small molecules

Question 12

what are podocytes?

Answer 12

they help to form a filtration barrier with endothelial cells

Question 13

what stops proteins getting through into the tubular fluid?

Answer 13

the negative charge of the podocytes and the masement membrane

Question 14

what does GFR stand for? and what is it?

Answer 14

glomular filtration rate and its represents the flow of plasma from the glomerulus into Bowman’s space over a specified period and is the chief measure of kidney function

Question 15

what cells are in the juxtaglomerular apparatus and what do they secrete?

Answer 15

it includes JG cells and they secrete renin

Question 16

does the afferent arteriole run into or out of the kidney?

Answer 16

it goes into the kidney

Question 17

what is the nephrin?

Answer 17

it is where the reabsorption of water occurs

Question 18

what does the juxtaglomerular apparatus do?

Answer 18

it helps reulate renal blood flow
glomerular filtration rate
it also indiretly modulates Na+ balance and systemic BP

Question 19

what are macula densa cells sensitive to?

Answer 19

theyre sensitive to the level of sodium present in the filtrate

Question 20

what is an off target effect of beta blockers?

Answer 20

they indirectly inhibit the release of renin

Question 21

what is glomerular filtration controlled by?

Answer 21

its controlled by diameters of afferent and efferent arterioles

Question 22

what does autoregulation do?

Answer 22

it maintains blood supply and glomerular filtration rate and prevents high blood pressure surges from damaging the kidneys

Question 23

what is the juxtaglomerular apparatus made up of?

Answer 23

the afferent and efferent arterioles and the distal convoluted apparatus

Question 24

what happens at the juxtaglomerular apparatus?

Answer 24

• at this site, there are specialised cells in both the afferent arteriole and the macula densa
• its believed to be involved in feedback control of renal blood flow and glomerular filtration rate.

Question 25

what do macula densa cells do?

Answer 25

they respond to changes in the rate of flow and the composition of tubule fluid and they control renin release from specialised granular renin-containing cells in the afferent arteriole

Question 26

what is fluid driven by when it goes from the capillaries into the tubular capsule?

Answer 26

its driven by hydrodynamic force opposed by the oncogenic pressure of the plasma proteins to which the capillaries are impermeable to

Question 27

where are all the low molecular weight constituents found in the JGA?

Answer 27

theyre found in the filtrate

Question 28

what molecules are kept in the blood rather than the filtrate after the JGA?

Answer 28

albumin and larger proteins are retained in the blood

Question 29

what is high hydrostatic pressure at glomerular capillaries due to?

Answer 29

its due to short, wide afferent arterioles having low resistance to the flow and long, narrow efferent arterioles having high resistance

Question 30

what does a low dose of angiotensin II cause to the efferent arteriole ?

Answer 30

it causes constriction of the blood vessel

Question 31

what things can cause the afferent arteriole to dilate?

Answer 31

-prostaglandins
- kinins
- dopamine (low dose)
- ANP
- NO

Question 32

what causes the efferent arteriole to constrict?

Answer 32

• high dose of angiotensin II
• noradrenaline (sympathetic nerves)
• endothelin
• ADH

Question 33

what causes an efferent arteriole dilation?

Answer 33

an angiotensin II blockade

Question 34

what is long term blood pressure controlled by?

Answer 34

it controlled by controlling blood volume

Question 35

what is a reduction in renal pressure due to?

Answer 35

intrarenal redistribution of pressure and increased absorption of salt and water

Question 36

what does angiotensin II do in the kidneys?

Answer 36

it causes direct constriction of the renal arteries and stimulates aldosterone synthesis

Question 37

what do diuretics have an effect on?

Answer 37

thyeve got a direct effect on blood and the levels of sodium

Question 38

what happens if cells are loaded with sodium?

Answer 38

they become loaded with water as sodium has a high osmotic value, this causes the blood vessels to become rigid which reduces the volume within the tissue and makes the tissue tension lower as the blood vessels are more rigid

Question 39

what is vascular edema and why would people be given diuretics?