Capillary filteration & lymphatic system

1. Capillary Filtration & Lymphatic System
Dr. Sara Sadiq
(MBBS, M.Phil)

2. 1. Function of
precapillary
sphincter?
2. Forces tending to
move fluid inward?
3. Forces tending to
move fluid outward?

6. Capillary Fluid Filtration
• Capillary hydrostatic pressure  force fluid outward
• Interstitial hydrostatic pressure  force fluid inward
• Capillary plasma colloidal osmotic pressure  force fluid inward
• Interstitial plasma colloidal osmotic pressure  force fluid outward
• The sum of these forces  the net filtration pressure
+ net fluid filtration
-fluid absorption

9. Arterial end
• Forces Tending to move fluid outward:
Capillary pressure = 30
Interstitial free fluid pressure = 3
Interstitial colloid pressure = 8
Total outward force = 41
• Forces tending to move fluid inward:
Plasma colloid pressure = 28
Total inward force = 28
• Summation of forces: Outward = 41
Inward = 28
Net filtration = 13

10. Venous end
• Forces tending to move fluid inward:
Plasma colloid pressure = 28
Total inward force = 28
• Forces Tending to move fluid outward:
Capillary pressure = 10
Interstitial free fluid pressure = 3
Interstitial colloid pressure = 8
Total outward force = 21
• Summation of forces: Inward = 28
Outward = 21
Net absorption = 7

12. Starling Equilibrium for Capillary Exchange
• Mean forces tending to move fluid outward:
Plasma colloid pressure = 17.3
Interstitial free fluid pressure = 3
Interstitial colloid pressure = 8
Total outward force = 28.3
Total inward force = 28
• Mean forces tending to move fluid inward:
Capillary pressure = 28
• Summation of mean forces: Outward = 28.3
Inward = 21
Net outward force = 7

13. Edema

16. Lymphatic fluid, formed by the
slight mismatch between filtration
and absorption in the capillaries,
returns to the blood in the veins.

20. Elephantiasis
Chronic, often extreme
enlargement and hardening of
cutaneous and subcutaneous
tissue, especially of the legs and
external genitals, resulting from
lymphatic obstruction and
usually caused by infestation of
the lymph glands and vessels
with a filarial worm.

21. Thank You