Microcirculation, Fluid Exchange, Lymphatic System Flashcards
What drives the movement of materials across a capillary wall?
active and passive forces
T/F the tissue controls its own blood flow in relation to its metabolic need
True
What is the term used for the main arterial supply to any tissue?
Nutrient artery
T/F metarterioles have a muscular coat
False
Which structure is considered the most permeable to plasma proteins?
Brain
Which structure is considered the least permeable to plasma proteins?
Liver
Why is blood flow not continuos through capillaries?
Vasomotion - intermittent flow of blood through capillaries
List a factor affecting vasomotion
Oxygen concentration
What does the average function of the capillary system depend on?
Average blood flow, capillary pressure, and rate of transfer
What is the most important process of nutrient exchange?
Diffusion
Which type of soluble substances diffuse directly through cell membranes? I.E they don’t pass through pores
Lipid-soluble
What is proportional to the net diffusion rate of a substance?
Concentration difference between the two sides of the membrane
List the 2 structures that make up the interstitium
- collagen fiber bundles
- proteoglycan filaments
What are the 2 things that make up proteoglycan filaments?
Hyaluronic acid and protein = reticular filament “brush pile”
What is the state of matter between cells?
Gel
How much percentage of free fluid in the interstitium?
1%
Which element of Fick’s law of diffusion is influenced by temperature?
Diffusion Coefficient (D)
Rate of diffusion = ( DA [Sc - Si] ) / change x
concentration difference (S)
Area (A)
Distance (change x)
Define osmosis
Water movement through diffusion
Describe water movement
It moves toward area of higher solute concentration
What is the concentration of plasma proteins within capillary?
7.3 g/dL
The interstitial concentration of proteins is ____g/dL
2
T/F proteins within capillary walls are impermeable to plasma proteins
True
Capillary pressure, plasma colloid osmotic pressure, Interstitial fluid pressures, interstitial colloid osmotic pressure regulate what ?
fluid filtration
What causes osmotic pressure?
Plasma Proteins
What pressure prevents significant loss of fluid volume from blood into interstitial spaces?
Colloidal osmotic pressure
If net filtration pressure is positive, what process will take place from capillary to interstitium?
Filtration
If net filtration pressure is negative, what process will take place from capillary to interstitium?
Reabsorption
What is the average capillary pressure?
17.3 mmHg
What type of pressure is negative ?
Interstitial fluid pressure (-3 mmHg)
What is the major determinant of plasma colloidal osmotic pressure (28 mmHg)?
plasma proteins - ALBUMIN
How can you measure plasma colloidal osmotic pressure?
Freezing point depression
T/F there are more proteins inside capillaries than outside
False - more outside
What is the name of the equilibrium for capillary exchange?
Starling equilibrium
What is the average capillary pressure at the arterial end of the capillary?
15-25 mmHg
At which end does fluid get absorbed back into the capillaries?
Venous end
Describe the difference of the venous end vs the arterial end of the capillary
Arterial end: fluid filters out due to net outward force
Venous end: fluid moves inward due to the - net force
Net hydrostatic pressure will favor:
filtration
Net osmotic pressure will favor:
reabsorption
The normal pressure created by proteins in plasma is ______ mmHg
28
The pressure in interstitial fluid is ____ mmHg
8
Where is the osmotic effect greater, in the capillary fluid or in the interstitial fluid?
Capillary fluid
Describe reabsorption (from where to where does it happen?)
From interstitium to capillary
What causes water to move by bulk flow?
Hydrostatic pressure difference
What is favored with net hydrostatic pressure, filtration or resorption?
filtration
T/F Lung capillaries are less permeable to plasma proteins
False
How much liters per day are in the lymph?
2-3 L
Where is lymph derived from?
Interstitial fluid
Lymph formation in which location can be of higher protein concentration?
Liver
Lymph flows faster in the thoracic duct or in other channels?
Thoracic duct
What is promoted with increased interstitial fluid?
Lymph flow
The excessive filtration of fluid or depressed lymphatic function can lead to what?
Edema
