Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ME2019 PART 1 > Homeostasis 2 > Flashcards

Homeostasis 2 Flashcards

1
Q

Homeostatic reflexes are represented by reflexes which may be..?

A

Neural

Hormonal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do the mechanisms of homeostasis maintain?

A

O2 and CO2

Waste and ions

Blood pressure and blood volume

Nutrient level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What percentage of body weight does water make up?

A

60%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is homeostatic regulation of water crucial?

A

Because water affects the concentration of everything else

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is water regulated?

A

Input by thirst mechanism

Output by regulation of kidney function

Other processes which are not regulated towards water balance, such as sweating which is for temperature regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What three compartments is water split between?

A

Intracellular fluid (ICF)

Interstitual fluid (ISF, fluid between cells)

Plasma (fluid component of blood)

ISF and plamsa make up extracellular fluid (ECF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does water move between compartments?

A

Water can move through all three compartments freely, but movement is subject to forces such as osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does fluid pass from ECF and ICF

A

Crosses the cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does fluid move between plasma and ISF?

A

Crosses the capillary wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the permeability of the cappilary wall?

A

Permeable to everything except plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain the permibility of the cell membrane?

A

Selective permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the ratio of water distribution across the compartments?

A

1/3 in ECF and 2/3 in ICF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is water distributed in ECF

A

80% in ISF

20% in plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do proportions of water vary with?

A

Sex and age

Woman and older people have higher proportions of fat than muscle (70% of muscle is water whereas 10% of fat is water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is plasma described as the dynamic component of the ECF?

A

Because it is continuously moving through vessels by the pumping action of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What nutrients does plasma exchange with ISF through the cappilary wall?

A

O2

Glucose

Ions

CO2

Urea

17
Q

Can exchange take place through large vessels like arteries?

A

No because the walls are too thick for exchange to take place

18
Q

Is the composition of blood and ISF the same?

A

Yes, apart from plasma proteins which are too large to pass through the cappilary wall

19
Q

What is the dilution principle?

A

c = m/V

20
Q

What can the dilution principle be used to measure?

A

Body fluids

21
Q

What should be remembered when using the dilution principle?

A
  1. c = m/V becomes V = m/c
  2. Only plasma can be sampled, so only compartments which plasma is a component of can be measured directly
  3. The nature of barriers which seperate compartments is crucial in determining the test substance
22
Q

What components can be measured directly?

A
  1. Plasma volume (measure plasma protein using dye)
  2. ECF (something that crosses cappilary wall but not the cell membrane like 24Na+
  3. Total body water, TBW (water because no barriers, use heavy water D2O)
23
Q

What compartments can be calculated indirectly?

A

ISF and ICF

ISF = ECF - PV

ICF = TBW - ECF

24
Q

What do you need to remember when calculating fluid levels?

A

To subtract any secretions or metabolism

25
Q

Why is the composition of the ECF very different from the ICF?

A

Because the cell membrane acts as a selective barrier

26
Q

How do ion concentrations of the ECF compare to the ICF?

A

More Na+ and Cl- outside the cell

More K+ inside the cell

27
Q

Why must large concentration gradients of ions be maintained?

A

For nerve function

28
Q

What does hyper mean?

A

Greater than normal

29
Q

What does hypo mean?

A

Less than normal

30
Q

What does aemia mean?

A

In the blood

31
Q

What does uria mean?

A

In the urine

32
Q

What does ‘glyc’ mean?

A

Relates to glucose

ME2019 PART 1 (55 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions