Lymphatics

Question 1

Lymphatics

Answer 1

Dense network of channels that function on conjunction with circulatory system for one-way transport of ISF, proteins, lipids, waste products back to thoracic duct

o Interstitial fluid vol = 10% capillary filtrate

Question 2

Driver of Lymphatics

Answer 2

mainly driven by NO-dependent rhythmic ctx of lymph vessel SmM, SkM ctx (lymph pump) in conjunction with valves

Question 3

Where are lymphatic vessels not present?

Answer 3

retina, bone, brain

Question 4

Edema

Answer 4

Excessive fluid accumulation in lung, intestine, liver (overflow organs) can result in fluid collection in alveoli, intestinal lumen, peritoneal cavity

Question 5

Consequences of Edema

Answer 5

Interstitial or cellular edema increases diffusion distance for oxygen, other nutrients

Collapses capillaries in swollen tissue (capillary no reflow), especially in encapsulated organs such as brain, kidney

Also at to limit diffusional removal of potentially toxic byproducts of cellular metabolism
o compromised cellular metabolism, impaired nutritive tissue perfusion

Question 6

4 MOA Edema

Answer 6

Increased capillary hydrostatic pressure
Decreased capillary oncotic pressure
Increased hydraulic conductance
Impaired lymphatic drainage

Question 7

increased capillary hydrostatic pressure

Answer 7

 Arteriolar dilation
 Venous constriction
 Increased venous pressure
 Heart failure
 ECF vol expansion

Question 8

Decreased Capillary Oncotic Pressure

Answer 8

 Decreased plasma protein concentration
 Severe liver failure/failure to synthesize protein
 Protein malnutrition
 Nephrotic syndrome/renal dz (PLN): loss of protein in urine

Question 9

Increased Hydraulic Conductance

Answer 9

 Burn
 Inflammation = release of histamine, cytokines

Question 10

Impaired Lympahtic Drainage

Answer 10

 Standing: lack of skeletal m compression of lymphatics
 Removal, irradiation of LNs
 Parasitic IFX of LN