Water balance Flashcards Preview

Kidneys and Hormones > Water balance > Flashcards

Flashcards in Water balance Deck (45):
1

What determines the plasma volume that perfuse organs?

Amount of water in the blood

2

What is hyperosmolality?

Too little water

3

What are the symptoms of hyperosmolarity?

Diarrhea

Vomiting

Negative water balance

Reduced water volume

Increased blood viscosity

Headache

Cramps

4

What are the symtoms of hyposmolality?

Low serum sodium levels

Headache

Vomiting

Confusion

Seizures

Coma

Muscle weakness

5

How much water is lost by insensible losses?

0.5 - 1L

6

What are insensible losses?

Non-urine losses

Sweating, breathing, faeces

7

How much water is lost in the urine a day?

1.5 L

8

What is the recommended volume of water that should be taken in during a day?

2 - 2.5 L

Through consumption of food and drink

9

What is the percentage of water in the body?

60%

10

What percentage of body water is found in the cells?

40% inside the cells - intracellular fluid

11

What percentage of body water is found between cells?

15% in between cells - interstitial fluid

12

What percentage of body water is found in blood plasma and lymph?

5%

13

Is water distribution between intracellular and extracellular compartments interchangeable?

Yes

14

What regulates the movement of water to and from the intracellular compartment?

Osmotic pressure

15

What is the major solute determining osmotic pressure in the intracellular compartment?

Potassium

16

What is the major solute determining osmotic pressure in the extracellular compartment?

Sodium

17

What is the plasma oncotic pressure?

Pressure exerted by plasma proteins that cannot move across capillary walls

18

What are the forces that determine the water distribution in the vascular compartment?

Oncotic pressure

Hydrostatic pressure

19

What does the hydrostatic pressure do to water distribution?

Pushes water out of the vascular space

20

What does the oncotic pressure do to water distribuyion?

Draws water into the vascular space

21

What happens to the blood pressure in high plasma protein levels?

High blood pressure

22

What is plasma oncotic pressure?

Pressure exerted by plasma proteins that cannot move across capillary walls

23

What are examples of specialised structures maintains perfusion of vital organs?

Baroreceptors in the aortic arch and carotid sinus

Osmoreceptors in the hypothalamus

JG cells in the kidney

24

Where are baroreceptors found?

In the aortic arch and carotid sinus

25

Where are the osmoreceptors found?

In the hypothalamus

26

Where are the JG cells found?

In the kidney

27

What do baroreceptors react to?

Changes in vascular tone and cardiac output

28

What do baroreceptors do to maintain homeostasis?

Cause volume changes

29

What do osmoreceptors in the hypothalamus react to?

Thirst

Vasopressin release

30

What do osmoreceptors do to maintain homeostasis?

Causes osmolality changes

31

What do JG cells in the kidney react to?

Salt and water reabsorption

Renin-angiotensin system

32

What do JG cells in the kidney do to maintain homeostasis?

Cause pressure changes

33

What is the effective circulating volume?

Part of the extracellular volume in the arterial system perfusion the organs

34

What is the average effective circulating volume of a 70 kg person?

700 ml

35

What maintains the effective circulating volume?

Total body sodium

Main extracellular solute holding water

36

Control of sodium balance through renal excretion is key to control circulating volume

TRUE or FALSE

TRUE

37

Pathogenesis of heart failure

Reduced blood pressure induces fluid retention by the kidneys and expansion of the extracellular compartment

Effective circulating volume is low

Water is in the same volume but in the wrong place - should be in the vascular space, not extracellular compartment

38

During heart failure, the decreased volume of water in the vascular space arises since the total body water is decreased

TRUE or FALSE

FALSE

The volume of water in the body is normal, just in the wrong compartment

39

What is water immersion?

Bathing in cold water after exercise

40

Why is water immersion beneficial?

Increases the pressure of the body and causes blood to go from the legs to the heart

41

What does water volume do to circulating volume and urine output?

Increases them

42

What are the benefits of water immersion?

Induces natriuresis by inducing vasopressin release

Induces diuresis

43

What is natriuresis?

Decrease in sodium concentration in the extracellular space

More sodium lost in the urine

44

Why is the induction of diuresis helpful?

Increases volume of water lost in conditions of water and salt retention

45

What is diuresis?

Increased urine output