sodium and water balance

Question 1

what secretes steroids?

Answer 1

adrenal glands

Question 2

what secretes ADH?

Answer 2

-posterior pituitary gland

Question 3

what effect does ADH have on peeing?

Answer 3

ADH makes you pee less (anti diuretic hormone) as it causes water to be reabsorbed into the renal tubules

Question 4

what effect does increased ADH have?

Answer 4

it causes you to have a small volume of concentrated urine (high osmalarity)

Question 5

what effect does decreased ADH have?

Answer 5

it causes a large volume of dilute urine (low osmolality))

Question 6

what is urine concentration/ dilution measured?

Answer 6

using urine osmolality

Question 7

does concentrated urine suggest high or low osmolality?

Answer 7

-high osmolality

Question 8

does dilute urine suggest high or low osmolality?

Answer 8

low osmolality

Question 9

what controls sodium balance?

Answer 9

steroids

Question 10

what is mineralocorticoid activity?

Answer 10

• the effect of steroids on Na+ balance

- this refers to Na+ reabsorption in renal tubules in exchange for K+/H+

Question 11

what steroids have mineralocorticoid activity?

Answer 11

• aldosterone (the main one)

- other steroids such as cortisol

Question 12

what effect does too much mineralocorticoid activity have ?

Answer 12

-sodium gain

Question 13

what effect does too little mineralocorticoid activity have?

Answer 13

-sodium loss

Question 14

what causes a sodium concentration to be low?

Answer 14

-too little sodium or too high water concentration

Question 15

is there more water intracellularly (inside cells) or extracellularly (outwith of cells)?

Answer 15

more water intracellularly (double)

Question 16

is there more sodium intracellularly (inside cells) or extracellularly (outwith of cells)?

Answer 16

more sodium extraceullar due to less water extracellularly

Question 17

when you gain/lose water, which compartment does it go to?

Answer 17

loss/gain of water goes to the whole body (intracellular and extracellular compartments)

Question 18

when you gain/lose sodium, which compartment does it go to?

Answer 18

it only goes to the ECF (extracellular fluid compartment)

Question 19

if you lose sodium from the ECF what occurs to the water?

Answer 19

you lose water with it

Question 20

if you gain sodium from the ECF what occurs to the water?

Answer 20

you gain water with it

Question 21

what do the kidneys do if the blood volume is too high?

Answer 21

-kidneys will excrete sodium, causing water to go with it, decreasing blood volume

Question 22

what do the kidneys do if the blood volume is too low?

Answer 22

-kidneys will reabsorb sodium, reabsorbing water with it and increasing blood volume

Question 23

what effect does primary adrenal insufficiency have on sodium and water levels?

Answer 23

• they can’t make the steroid hormones that control sodium balance
• so will not reabsorb sodium from the kidneys as they would normally do
• meaning you would lose sodium and water with it

Question 24

what affect does vomiting have on sodium/water levels?

Answer 24

-vomiting would make you lose sodium for gut and water along with it

Question 25

whats more common hypernatreamia due to too much water or due to too little sodium?

Answer 25

too much water

Question 26

are the changes or hyponatremia/hypernatraemia more dramatic in sodium loss/gain or water loss/gain?

Answer 26

sodium loss/gain as it is only lost/gained in ECF whereas water is lost from everywhere

Question 27

clinical signs of hyponatraemia due to too much sodium?

Answer 27

- clinical dehydration - hypotension - tachycardia - small volume concentrated urine - decreased skin elactisity

Question 28

clinical signs of hypernatraemia due to too much sodium?

Answer 28

- clinical signs of extracellular fluid compartment - raised JVP - pleural effusion - ascites - bibasal crepitaitions

Question 29

clinical signs of hyponatraemia/ hypernatraemia due to water loss/excess?

Answer 29

not always obvious due to water loss occuring in both intracellular and extracellular compartments

Question 30

what causes hyponatramia due to sodium?

Answer 30

- There may be Na+ loss in adrenal insufficiency losing sodium from kidneys - sodium lost from the gut due to vomiting/diarrhoea - it may be lost from the skin from third degree burns

Question 31

what causes hyponatramia due to water?

Answer 31

- most common is decreased H20 excretion due to SIADH (syndrome of inappropriate antidiuretic hormone secretion) where too much ADH is made - or increased intake of water from drinking too much

Question 32

what causes hypernatramia due to sodium?

Answer 32

- if there is increased H20 loss in diabetes insipidus as ADH is disrupted - decreased H20 intake in very young or very old

Question 33

what causes hypernatramia due to water?

Answer 33

increase sodium intake from IV meds and near drowning

Question 34

what is treatmeant for hyponatraemia due to too little sodium?

Answer 34

-give sodium replacement

Question 35

what is treatmeant for hyponatraemia due to too much sodium?

Answer 35

remove sodium by giving loop diuretics

Question 36

how would water be removed in hyponatraemia?

Answer 36

-fluid restrict

Question 37

how would water be given in hypernatraemia?

Answer 37

- give dextrose IV | - dextrose contains glucose so it can be metabolised in a controlled way and release H20 into the body

Question 38

what may a patient experience if sodium level is very high or very low?

Answer 38

- altered consciousness - confusion - nausea - vomiting - fitting

Question 39

what are the two kidns of stimuli for ADH release?

Answer 39

- osmotic (in health) | - non osmotic (in disease)

Question 40

what are examples of non osmotic stimuli?

Answer 40

- hypovolaemia - pain - nausea/vomiting

Question 41

what does an oedema suggest?

Answer 41

too much water in interstitial fluid

Question 42

does oedematous patient have too much water or sodium?

Answer 42

-too much water and sodium

Question 43

how is an oedematous patient treated?

Answer 43

with loop diuretics as it causes a loss of sodium and so also water