Tissue fluid Flashcards
Function, contents, location of tissue fluid?
Blood plasma but without the plasma proteins or RBC
Transports O2 and nutrients from blood to cells and CO2 and other waste from cells to blood
Bathes all cells
What is tissue fluid and why doesnt it contain plasma proteins or RBC
It is plasma that has been forced out of the capillaries through pores to become tissue fluid. Proteins are too large to diffuse out
Another name for blood pressure and what causes it?
Hydrostatic pressure caused by the contraction of the left ventricle pushing blood around the body (heart pumping blood)
Why is tissue fluid forced out of capillaries at the arterial end 4
They r under high hydrostatic pressure from contracting of the LV
Water potential of the blood is lower than that of the tissue fluid so water wants to enter the blood via osmosis
But the hydrostatic pressure is greater than the osmotic pressure
Net movement of fluid out of blood, into tissue fluid
Why is the water potential of the blood lower than that of the surrounding tissue fluid
The blood contains dissolved materials and cells and plasma proteins but the tissue fluid only contains the dissolved substances
What occurs between the exit and re-entrance of tissue fluid into the blood
Exchange of material between tissue fluid and the cells which it bathes: O2, glucose, amino acids into cells, CO2 and waste out into fluid
Why does hydrostatic pressure decrease across the capillaries 2
Large TOTAL crossectional area of capillaries means blood loses energy/ pressure bc of friction
Loses pressure because fluid is leaking out through pores in capillaries
Why does tissue fluid re enter the capillaries at the venous end
Hydrostatic pressure has been lost
Water potential of the blood is very low bc of retention of plasma proteins alongside loss of fluid so water wants to re enter blood
Osmotic pressure inwards is greater than hydrostatic pressure
Tissue fluid enters the capillaries carrying waste products from cells
Does tissue fluid have it’s own hydrostatic pressure
Yes, every liquid does, though it is ver small, pushing inwards to the capillaries
Does the water potential of the blood change, why?
No, because CO2 and waste products inwards replaces the O2 and materials outwards.
Iss there a greater net movement of fluid into or out of vessels to bathe cells
Out of vessels
What percentage of tissue fluid that leaves the capillaries at the arteriole end is forced back into the capillaries at the venous end
90-99%
How is excess tissue fluid drained
By the lymphatic system, when it enters it is called lymph
Lymph compared to tissue fluid
Lymph has more lipids and CO2
Less O2 and nutrients
Lymph vessels are blind ended meaning..
They are closed at one end (the end at the capillaries)
What happens to the lymph is the lymph vessels eventually and where
It is returned to the blood stream by travelling throught the thoracic duct to the subclavian vein in the neck
In which regions of the body are lymph nodes found
Armpit
Groin
Neck
Gut
Function of lymphnodes
Hold lymphocytes which intercept pathogens to prevent the spread of microbial infection in the body
Affect of low blood protein on the lymphatic system?
The water potential of the blood will be higher
Less tissue fluid re enters the blood vessels at the venous end
Causes oedema
Oedema?
Fluid retention in tissues
What occurs as a result of blocked lymph vessels
The affected limbs can swell due to accumulation of tissue fluid
Why is lymph returned to the blood stream slowly 3
Lymphatic system separate from the circulatory system
So it is not affected by the contraction on the LV
So lymph is under low pressure
