Microcirculation Physiology Flashcards
what are the components of the interstitum?
collagen fibre bundles
proteoglycan filaments
what is the composition of proteoglycan filaments
98% hyaluronic acid and 2% protein
what is meant by the term tissue gel
the entrapment of interstitial fluid in the proteoglycan filaments
where is free fluid found in the interstitial space
in small rivulets and vesicles
what is the capillary oncotic pressure
28 mmHg
what is the interstitial oncotic pressure
5-8 mmHg
what is capillary hydrostatic pressure
35-12 mmHg
how much fluid is lost from capillaries
2-3L
where are prelymphatics found?
superficial skin, CNS, muscles and brain
what is the function of the lymphatic system?
return proteins and larger matter to the circulation
control volume and pressure of interstitial fluid
immune response
how much greater is blood pressure in the feet that the top of the body
+90 mmHg causing blood to pool in high pressure at the feet
what causes fainting?
the low pressure of blood to the head and lack of adequate circulation
fainting equalises pressure
what is orthostatic postural hypotension
the decrease in BP caused by 500 ml of blood falling from upper body to legs when standing up
how is orthostatic postural hypotension opposed
reflex vasoconstriction in legs and lower abdomen
how does the sympathetic system increase venous return
increases venous tone, decreasing capacity
