homeostasis

Question 1

what is homeostasis

Answer 1

prevent disturbance in the system

Question 2

what is the life equation

Answer 2

Nutrients + O2 = Energy (ATP) + CO2 + wastes

Question 3

what is negative feedback

Answer 3

There is oscillation around the set point.
2. Restore the regulated variable after its initial displacement, but cannot prevent it happening.

RESTORE CONDITIONS

Question 4

what is a feed forward system

Answer 4

additional receptors permit system to anticipate change and therefore activate response earlier.

early warning - pre-emptive strike

Question 5

positive feed back

Answer 5

greater disturbance

SELF AMPLIFICATION

Question 6

how much body weight is water

Answer 6

60%

Question 7

basic homeostasis concept

Answer 7

What we gain, we must lose

What we lose, we must replace

Question 8

what are the 3 water compartments in the human body

Answer 8

Intracellular fluid

Interstitial fluid (fluid between cells)
Plasma (fluid component of blood)

Question 9

what is the water content breakdown between ICF and ECF

Answer 9

ICF 2/3 or 28 literes
ECF 1/3 or 14 litres

interstisal fluid is 11 litres
plasma is 3 litres

Question 10

total body water content

Answer 10

42 litres (typical 70kg 21yo man)

Question 11

how does water content between sex and age change

Answer 11

decrease with age as more fat

fat carries less water
by that logic females have less water content

Question 12

what is the difference between plasma and ISF

Answer 12

plasma proteins which are too large

Question 13

what is the dilution principle

Answer 13

c = m/v,  v = m/c

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Question 14

what is the only body fluid that can be measured to see water content

Answer 14

ONLY plasma can be sampled, only compartments of which plasma is a component can be measured directly (plasma, ECF, TBW).

Question 15

how is plasma measured

Answer 15

Evans blue or I125albumin.

radioactive lables attached to plasma proteins

Question 16

how is ECF measured

Answer 16

something that freely crosses capillaries
but to large for cell membrane
24Na+ , 36Cl-,

Question 17

how is total body water measured

Answer 17

use a loading dose of water

Question 18

how is the ICF and interstisial fluid measured

Answer 18

ISF = ECF-PV,

ICF = TBW-ECF

Question 19

what do these terms mean 
hypo
hyper
Aemia
uria 
glyc

Answer 19

less than normal 
more than normal 
in the blood
urine 
glucose

Question 20

what happens if there is an extreme homeostatic disturbance

Answer 20

may fall off the homeostatic plateau and lead to DEATH.