Module 2 Test Flashcards
Define diffusion.
migration of particles from higher to lower concentration
There is more O2 in blood than in _________, so
02 _________ blood capillaries by process of _______.
tissues
leaves
diffusion
Define diffusion distance, as it relates to lymphedema.
distance between blood capillaries and cells in the tissues
Swelling ___________ the normal diffusion distance.
increases
Name some ways increased diffusion distance negatively impacts tissues?
- local immune response is compromised
- nutritional supply to cells suffer
- frequent infections/increased risk for infections
SKIN CARE IS IMPORTANT TO MANAGE RISK
Define COP pl
the force of proteins to hold onto water in the blood plasma (equals 25 mm Hg)
In healthy individuals, COP pl is ________ COP ip.
greater than
Define COP ip
the force of proteins to pull water into the interstitial spaces
In a 24 hour period, approximately what percentage of circulating proteins will leave the blood (at the blood capillary), and move into the interstitial space?
50%
Is BP higher or lower than BCP?
higher
What is the average BP at the artery?
100 mm Hg
What is the average BP at the vein?
3-4 mm Hg
Return of blood to the heart depends on…
- muscle pump
- functioning valves
- diaphragmatic breathing
- suction effect of heart at diastole
- pulsation of adjacent arteries
How does the precapillary sphincter impact the flow of blood to the capillaries, when in constricts?
contracts = less blood in capillaries - less volume = decreased BCP
Filtration occurs at the _______ end of the blood capillary.
arterial
Reabsorption occurs at the ______ end of the blood capillary.
venous
Define reabsorption.
Process by which water is reabsorbed from tissues back into the venous end of the BC - water picks up waste products and returns them to venous system.
What percentage of H2O is reabsorbed by venous system?
80-90%
How does H2O remain in the interstitial spaces?
Proteins (hydrophilic macromolecules) exist in the interstitial spaces, and hold back 10-20% of the water. This is referred to as the lymphatic load of water, or net filtrate. Removal of LL is the responsibility of the lymphatic system.
Describe the classic view of Starling’s Law.
Arterial blood capillary pressure (29 mm Hg) > colloid osmotic pressure of the plasma, causing protein to be forced out into the interstitial space, at the level of arterial capillaries. On the venous end, blood capillary pressure (14 mm Hg) < colloid osmotic pressure of the plasma, favoring return of fluid into the venous system (80-90%). Proteins are unable to cross the semi-permeable membrane back into the venous system, resulting in protein rich fluid in the interstitial space. This fluid, is managed by the lymphatic system.
Name the components of CDT.
- MLD
- skin care
- exercise
- compression
How is compression beneficial in lymphedema?
It increases the tissue pressure directed against the capillaries, which hinders filtration and supports reabsorption.
Define active hyperemia.
anything that causes vasodilation and increased arterial flow
How does active hyperemia influence fluid homeostasis?
increased arterial flow - increased volume - higher arterial BCP - increased filtration - increased net filtrate
Name some common causes of active hyperemia.
- deep tissue massage
- inflammation/infection
- temperature/thermal modalities
- sunbathing
- vigorous exercise
Define passive hyperemia.
increase in BCP caused by an obstruction of venous return or deficiency of venous outflow - blood pools into capillaries
How does the body respond to active and/or passive hyperemia?
activation of the lymphatic safety factor, through increase in lymphangiomotoricity and increased lymph time volume
Define functional reserve.
The difference between transport capacity (LS working at max amplitude and frequency) and lymphatic load, as the LS will only work as hard as it needs to (lymph time volume), to manage current LL.
i.e. the availability for compensation
Define dynamic insufficiency.
- healthy LS is overwhelmed
- AKA high volume insufficiency, where LL of H2O > TC
- LTV is “maxed out”
- results in EDEMA (which is a symptom)
Describe mechanical insufficiency.
- TC drops below normal amount of LL
- AKA low volume insufficiency
- due to damage to the LS
- results in LYMPHEDEMA (which is a disease)
Identify important characteristics of dynamic insufficiency.
- healthy LS
- TC is normal
- LL > TC
- protein concentration in tissue is normal
- high volume insufficiency
- MLD/CDT not indicated
- max LTV = TC
- results in edema
Identify important characteristics about mechanical insufficiency.
- unhealthy LS
- TC is subnormal
- LL could be normal, but > subnormal TC
- protein concentration in tissue is > than normal
- low volume insufficiency
- MLD/CDT indicated
- max LTV = subnormal TC
- results in lymphedema
(delete) Identified important characteristics of combined insufficiency. (?)
- unhealthy LS
- TC is subnormal
- LL is > normal and also than subnormal TC
- protein concentration in tissue is elevated
- Max LTV = subnormal TC
- MLD/CDT indicated
- results in lymphedema
Define combined insufficiency.
mechanical insufficiency (that was possible under control) with insult resulting in increased LL
What is the current gold standard diagnostic tool for lymphedema?
lymphoscintigraphy
How does the precapillary sphincter impact the flow of blood to the capillaries, when in dilates?
dilates = more blood in capillaries - greater volume = increased BCP
