deck_16348459 Flashcards
Diffusion
Passive movement high to low concentration
Transcytosis
Active transport of larger fat insoluble
Filtration
Movement of water higher to lower concentration
Diffusion occurs rapidly when?
short distance, large concentration gradient, small ions/molecules
Diffusion is important for?
solute exchange
How transcytosis works?
*
* Hormone enters one side of cell via pinocytic vesicle and exits other side
What is Bulk flow?
large numbers of ions, molecules, moving in same direction passively
Bulk Flow Filtration movement occurs where?
capillaries to interstitial fluid
Bulk Flow Re-absorption occurs where?
Interstitial fluid to capillaries
Filtration: Blood Hydrostatic Pressure
Pressure of blood on vessel walls pushes molecules out
Filtration: Interstitial Fluid colloid osmotic pressure
Interstitial fluid pulling from capillaries to IF
Re-absorption: Blood Colloid osmotic pressure
Albumins pull fluid from IF into blood
Re-absorption: Interstitial fluid Hydrostatic pressure
Pressure pushes fluid from IF to capillaries
Movement across capillary is largely dependent on?
Hydrostatic and osmotic pressure of blood
What is Net Filtration Pressure
Balance of pressures determining direction of fluid flow
What is edema?
Swelling - abnormal IF volume
What are hemodynamics
Factors affecting blood flow
Blood flow is dependent on which two factors?
Pressure Difference
Peripheral Resistance
Systolic Blood Pressure
Highest pressure attained in arteries during systolic contraction
Diastolic Blood Pressure
Lowest pressure attained in arteries during diastolic relaxation
Mean arterial pressure
average BP in arteries
Which is higher Arterial or Venous pressure?
Arterial
Capillary pressure is lower than artery because?
Increased surface area and blood spreading
Blood pressure in veins maintained by what two things?
Valves
muscular compression of veins
Capillary blood flow is slow and allows time for?
Time for capillary exchange
What is Venous Return
Amount of blood to right atrium per min
Where is highest pressure located
Aorta - pressure keeps decreasing from there
Peripheral Resistance is dependent on what 3 factors?
Size of lumen in vessel
Blood vessel length
Blood viscosity
How does size of lumen affect fluid movement
Smaller lumen, more resistance
Larger lumen, less resistance
How does blood vessel length affect fluid movement?
Longer the vessel, more resistance
How blood viscosity affects fluid movement
Increased solutes, etc.. increase viscosity = increase resistance