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Flashcards in Water physiology Deck (24)
1

How is the concentration of Na worked out?

How many moles of Na per 1L water

2

True or False
Water will follow sodium

True

3

Intracellularly, what is sodium exchanged for?

Hydrogen or potassium

4

Which steroids have mineralocorticoid activity?

Aldosterone
(Cortisol)

5

What happens if there is too little mineralocorticoid activity?

sodium is lost

6

What happens to water when sodium is lost?

Water is also lost

7

What hormone controls water loss in the kidney?

Anti-diuretic hormone

8

Where is ADH released from?

Posterior pituitary

9

If there is lots of ADH released what does this mean in the urine?

Concentrated urine i.e. water retention

10

If concentration of sodium is reduced what are the two factors that cause this?

Too little sodium
Too much water

11

If sodium concentration is increased what causes it?

Too much sodium
Not enough water

12

What can cause too much water?

SIADH
syndrome of inappropriate ADH

13

What can cause too little sodium?

Kidney disease e.g. Addisons
Excess sweating

14

What can cause too little water?

Diabetes insipidus

15

What can cause too much sodium?

Rare.
High salt feeds in infants

16

What is Addison's disease?

Adrenal insufficiency which results in lack of corticosteroids

17

Why does Addison's cause sodium loss?

Not enough steroid to regulate to can't retain Na+ in kidneys so loses Na+ and H2O

18

Why are Addisons patients hyperpigmented?

Excess ACTH from pituitary

19

What is an Addisonian crisis?

Severe hypotension leading to coma

20

Why might potassium be high in Addisons disease?

?

21

What stimuli can cause too much water?

Hypovolaemia/hypotension
Pain
N&V

22

How is water retained in SIADH?

ADH is secreted due to a stimuli and this causes water retention

23

If ADH levels are not high enough what drug can be given?

Desmopressin

24

What levels of sodium are worrying?

Less than 120
More than 155