C33. Fluid shift across the capillary wall: Pulmonary and systemic oedema

Question 1

what is the total body water amount

Answer 1

42 L (or 60% of body weight)

Question 2

how much of the body water is extracellular

Answer 2

1/3 or 14L

Question 3

how much of the extracellular fluid is interstitial

Answer 3

75% or 11L

Question 4

what is interstitial fluid

Answer 4

fluid that fills the spaces between cells in the body and acts as the go between blood and body cells.

Question 5

capillaries have how many layers of endothelial cells

Answer 5

one

Question 6

what do capillaries do as a function

Answer 6

facilitate exchange

Question 7

capillaries exchange using what methods

Answer 7

simple diffusion or convection

Question 8

what is paracellular

Answer 8

through the cells themselves (as in material passes through the capillaries)

Question 9

what is transcellular

Answer 9

movement of fluid between cells (through the gaps)

Question 10

what are the 3 types of capillaries

Answer 10

continuous, fenestrated and sinusoidal (discontinuous)

Question 11

what is exchanged at capillaries (2)

Answer 11

gases and water soluble substances

Question 12

what cant be exchanged at capillaries

Answer 12

proteins

Question 13

why cant proteins e exchanged at capillaries

Answer 13

too large in most capillary types
some fenestrated can facilitate a limited amount

Question 14

what other structure can facilitate protein movement

Answer 14

pinocytic vesicles

Question 15

are Water soluble substances lipid soluble

Answer 15

NO

Question 16

are gases lipid soluble

Answer 16

yes

Question 17

how do gases exchange through capillaries

Answer 17

Transcellular diffusion driven by partial pressure gradient and surface area available for exchange

Question 18

how do water soluble substances move exchange through capillaries

Answer 18

Paracellular diffusion driven by solute gradient and surface area available for exchange

Question 19

what is Starling’s forces equation

Answer 19

Jv=Kf [(Pc-Pi) - (𝜋c-𝜋i)]

Question 20

what is starling’s forces

Answer 20

Imagine you have a sponge (the capillary) and a bowl of water (the interstitial fluid). The sponge can soak up water or squeeze it out, depending on the pressures.

Hydrostatic Pressure:

Capillary Hydrostatic Pressure (Pc): Think of this as the sponge being squeezed, pushing water out into the bowl.
Interstitial Hydrostatic Pressure (Pi): This is like the water in the bowl pushing back against the sponge.
Osmotic Pressure:

Capillary Oncotic Pressure (πc): Imagine there are tiny magnets (proteins) inside the sponge pulling water back into it.
Interstitial Oncotic Pressure (πi): There are also tiny magnets in the bowl pulling water out of the sponge.
The overall movement of water depends on which forces are stronger. If the squeezing force (Pc) is stronger than the magnets in the sponge (πc), water moves out. If the magnets in the sponge (πc) are stronger, water gets pulled back in.

Question 21

explain Hydrostatic pressure:
1. Capillary hydrostatic pressure (Pc)
2. Interstitial hydrostatic pressure (Pi)

Answer 21

1. fluid wants to move out
2. fluid wants to move in

Question 22

explain Osmotic pressure:
1. Capillary oncotic pressure (πc)
2. Interstitial oncotic pressure (πi)

Answer 22

1. fluid being pulled into the capillary
2. fluid being pulled out of the capillary

Question 23

fluid going from lumen out to the interstitial space is referred to as….

Answer 23

filtration

Question 24

fluid going from the interstitial space into the lumen is referred to as….

Answer 24

absorption

Question 25

Explain Hydrostatic pressures - Capillary hydrostatic pressure (Pc)
Why? and which end ha the most?

Answer 25

• Favours filtration
  Product of arterial and venous pressures
  Highest at arterial end of capillary and falls along length

Question 26

Explain Hydrostatic pressures-Interstitial hydrostatic pressure (Pi)
how large is the pressure

Answer 26

○ Opposes filtration
○ Normally single digit values or slightly negative

Question 27

explain oncotic pressures -
Capillary oncotic pressure (πc)
(presence….. proteins?)

Answer 27

○ Opposes filtration
○ Product of presence of proteins in capillary lumen

Question 28

explain oncotic pressures - Interstitial oncotic pressure (πi)

Answer 28

○ Favours filtration
○ Product of presence of proteins in the interstitial fluid

Question 29

what does the lymph system do?

Answer 29

returns fluid from the interstitial fluid to the circulation

Question 30

Via what does the lymphatic system returns fluid from the interstitial fluid to the circulation?

Answer 30

lymphatic capillaries

Question 31

where do the lymphatic capillaries return the interstitial fluid to wards

Answer 31

the thoracic duct and into the great veins

Question 32

what do lymphatic capillaries contain

Answer 32

valves

Question 33

how does changes to starlings forces effect anything (thing of swelling)

Answer 33

Increased Capillary Hydrostatic Pressure (Pc):

What it means: Imagine squeezing a hose harder. More fluid gets pushed out.
Effect: More fluid leaves the capillaries and enters the tissues, which can cause swelling.
Decreased Capillary Oncotic Pressure (πc):

What it means: Think of the magnets inside the hose (proteins) getting weaker.
Effect: Less fluid is pulled back into the capillaries, so more fluid stays in the tissues, leading to swelling.
Increased Capillary Permeability:

What it means: Imagine the hose has more holes in it.
Effect: More fluid and proteins can leak out into the tissues, causing swelling and inflammation.
Decreased Lymphatic Drainage:

What it means: The side streets (lymphatic system) are blocked or not working well.
Effect: Extra fluid in the tissues isn’t being removed properly, leading to swelling

Question 34

explain pulmonary circulation in regards to resistance, capillary hydrostatic pressure, capillary osmotic pressure and lymphatic drainage

Answer 34

Pulmonary Resistance:
What it means: The resistance (or difficulty) for blood to flow through the lungs is much lower than in the rest of the body.
Effect: Blood can flow easily through the lungs.

Pulmonary Capillary Hydrostatic Pressure:
What it means: The pressure inside the tiny blood vessels in the lungs is low (about 8-11 mmHg).
Effect: This low pressure helps prevent fluid from leaking out into the lung tissues.

Capillary Osmotic Pressure:
What it means: The pressure created by proteins in the blood that pull fluid back into the capillaries is about 25 mmHg.
Effect: This helps keep fluid inside the blood vessels and prevents it from leaking into the lung tissues.

Efficient Lymphatic Drainage:
What it means: The lymphatic system in the lungs works well to remove any extra fluid that does leak out.
Effect: This prevents fluid from building up in the lung tissues, keeping them clear and healthy.

Question 35

what is Oedema

Answer 35

Oedema is when fluid builds up in the spaces between cells, causing swelling. There are different types of oedema depending on where the fluid accumulates.

Question 36

what is pulmonary oedema

Answer 36

fluid accumulation in the interstitial spaces of the lung

Question 37

what are some symptoms of pulmonary oedema

Answer 37

Symptoms: This can cause difficulty breathing (dyspnoea) and low oxygen levels (hypoxia).

Question 38

what is Peripheral Oedema?

Answer 38

Fluid builds up in the legs or other parts of the body.

Question 39

what are some symptoms of peripheral oedema

Answer 39

Symptoms: This causes swelling in the affected areas, like the legs.

Question 40

what is it called when Fluid builds up in the legs or other parts of the body.

Answer 40

peripheral oedema

Question 41

what kind of medication is used to treat oedema and why

Answer 41

Diuretics are medications that help the body get rid of excess fluid by making you urinate more.

Question 42

what patients do u give fluid to always

Answer 42

severe burns victims