Blood pressure L12 & L13 Flashcards
What percentage of the blood distribution in the cardiovascular system is located in the systemic veins and venules?
64%
-they are the blood reservoirs of the body
What does 64% resemble in relation to the blood distribution in the cardiovascular system?
systemic veins and venules’ reservoirs of blood
What percentage of the blood distribution in the cardiovascular system is located in the systemic arteries and arterioles?
13%
What does 13% resemble in relation to the blood distribution in the cardiovascular system?
Systemic arteries and arterioles
What percentage of the blood distribution in the cardiovascular system is located in the Pulmonary Vessels?
9% in the Right circuit ALTOGETHER
What does the 9% resemble in relation to the blood distribution in the cardiovascular system?
pulmonary circuit ALTOGETHER (of the right side)
What percentage of the blood distribution in the cardiovascular system is located in the heart?
7%
What does the 7% resemble in relation to the blood distribution in the cardiovascular system?
percentage in the heart
or
percentage in the systemic capillaries
What percentage of the blood distribution in the cardiovascular system is located in the systemic capillaries?
7%
site of exchange has Smallest amount of blood in the systemic circuit
What does the 7% resemble i relation to the blood distribution in the cardiovascular system?
percentage in the systemic capillaries
or
percentage in the heart
Where is there an overlap in identical percentages of the distribution of blood in the cardiovascular system?
Heart and the Systemic Capillaries (side of exchange has smallest amount of blood in the systemic circuit)
both contain 7% of blood
Where is the blood distribution in the cardiovascular system both 7%?
Heart
and the Systemic Capillaries (side of exchange has smallest amount of blood in the systemic circuit)
What percentage of the blood distribution in the cardiovascular system is located in the systemic circuit?
84%
64% + 13% + 7% = 84%
Veins are the reservoirs, so always more than arteries
Systemic veins and venules: 64%
Systemic arteries and arterioles: 13%
Systemic capillaries: 7% (same proportion as in heart- emphasises is so small, as is the smallest in systemic circuit as is the site of exchange (small and slow blood flow (1 RBC diameter of endothelium)))
What is the breakdown of percentages of the blood distributed in the cardiovascular system?
- Systemic Veins and Venules: 64%
- Systemis arteries and Arterioles: 13%
- Pulmonary circuit: 9%
- Heart: 7% (same as S.c)
- Systemic Capillaries: 7% (same as H. and is small((est) proportionately) as is slow site of exchange)
What contains the largest percentage of blood?
Systemic veins and venules (reservoirs) 64% out of total 84%
allows diversion of blood if the need quickly arises
done through vasoconstriction and vasodilation
Why do we have blood reservoirs?
allows diversion of blood if the need quickly arises
done through vasoconstriction and vasodilation
How do we divert blood reservoirs?
located in systemic veins (and venules)
done through RESERVOIR IN VEINS (vaso-) constricting (constriction) = vasoconstriction
done through RESERVOIR IN VEINS (vaso-) dilating (dilation) = vasodilation
What is the relationship between vasoconstriction/dilation and blood reservoirs?
vaso = veins
veins = are the blood reservoirs
therefore in order to divert blood reservoirs if quick demand arises you vasoconstrict and vasodilate
What does 120/80 mean?
Diastolic (press) /systolic (press)
What does the 80 in 120/80 mean?
Systolic pressure
What does 120 in 120/80 mean?
Diastolic pressure
Where is diastolic pressure mentioned?
in 120 in 120/80
Where is systolic pressure mentioned?
in 80 in 120/80
What are the diastolic/systolic pressures for when you have hypertension?
> 140/>90
What are the diastolic/systolic pressures for when you have a short life expectancy due to poor heart conditions?
200/140
What is hypertension a precursor to?
A whole bunch of cardiovascular problems
What are some risk factors of hypertension?
smoking
excess alcohol/binge drinking
obesity
lack of exercise
When the heart enlargens does the ejection fraction increase or decrease?
decrease
- as larger EDV
- can also result in short breath, venous congestion and heart failure (dilated cardio myopathy)
What can cause arteries to be weak?
Tortuosity = sharp bends
Plaques = blockage
weak points = rupture easily under high pressure
Can results in stroke or a coronary tear
What are the body’s major resistance vessel?
arteioles
Where is there a biggest amplitude in diastolic and systolic pressure
in the arteries and arterioles
Where is there the biggest reduction in amplitudes of diastolic and systolic pressure, and huge reduction of BP as well?
In arterioles
- SM allows this absorption of pressure and greatest resistance, to decrease amplitude
- enough to dampen pressure to give resistance to flow
When is there a pulsatile pressure big enough to be measured by a sphygmomanometer?
in the arteries and arterioles
What is the equation for MABP?
CO x TPR
What does CO cardiac output x TPR =?
MABP mean arterial blood pressure
TPR times what equals MABP?
Cardiac Output
CO x TPR = MABP
What is the equation of EF?
SV / EDV = (EDV-ESV) DIVIDED by EDV
e.g. on pressure-volume loop 80mL/120mL
Why is the flow rate in capillaries the same?
As Blood pressure Drives exchange
What is the driving force of filtration (NFP)?
Blood pressure
BP drives NFP
so in capillaries bp varies, BF stays relatively constant (Flowin=Flowout) - Flow rate is the same as BP drives exchange
That is why blood pressure has to be kept constant, as it drives exchange, which allows the muscle to have a constant supply of oxygen and nutrients
without constant blood pressure, the metabolising muscle wont get enough oxygen for energy or nutrients for nourishment, and there will be excess metabolic waste products and CO2 in the system
Where does 2x way exchange in the body occur?
In the capillaries
Capillary IF Cells
Is the Blood Hydrostatic pressure largest on the arterial initial or venous end of the capillary?
Arterial end,
due to the pressure drop at the arteriole end, which drives filtration
What type of condition is hypertension?
Chronic, high blood pressure
What do you have when you have chronic high blood pressure?
Hypertension
What happens if you have longterm hypertension?
Increased MABP Longterm
What is the relationship between longterm MABP/hypertension and Edema?
Long term MABP = increased Net Filtration = increased fluid out of capillaries =increased fluid into tissue (esp in lower limbs) =decreased reabsorption =edema = swollen tissue in lower limbs =swollen ankles (feet or legs)
What is the NFP?
Net filtration pressure
What is the equation for Net filtration pressure?
=(BHP+IFOP) - (BCOP+IFHP)
=Pressures driving filtration - pressures driving reabsorption
What is the equation (BHP+IFOP) - (BCOP+IFHP) for?
NFP
Net Filtration Pressure
Essentially what does (BHP+IFOP) - (BCOP+IFHP) mean?
Pressures driving filtration - pressures driving reabsorption
Is the Blood Hydrostatic pressure smallest on the arterial initial or venous end of the capillary?
venous end of the capillary
as it has been filtered and re-absorbed and lost pressure
as the blood had to travel down a pressure gradient
What are the pressures the are going out of the capillary?
BHP
IFOP
What are the pressures driving filtration?
BHP
IFOP
What are the pressures that are going into the capillary?
BCOP
IFHP
What are the pressures driving absorption?
BCOP
IFHP
What are the changes between the Net filtration and Net reabsorption as you go from arterial to venous end of the capillaries?
BHP is the only element of the ((BHP+IFOP) - (BCOP+IFHP)) equation to change
What is the pressure of BHP at the arterial end of the capillary?
35mmHg
What is the pressure of 35mmHg referring to in the capillaries?
BHP on the arterial end
What is the pressure of IFOP in the capillary?
1 mmHg
What is the pressure of 1 mmHg referring to in the capillaries?
IFOP
What is the pressure of BCOP at the arterial end of the capillary?
26mmHg
What is the pressure of 26mmHg referring to in the capillaries?
BCOP -at BOTH the arterial and venous end of the capillary - only BHP changes
What is the pressure of IFHP in the capillary?
0 mmHg
What is the pressure of 0mmHg referring to in the capillaries?
IFHP
What is the pressure of BHP at the venous end of the capillary?
16mmHg
What is the pressure of 16mmHg referring to in the capillaries?
BHP at the venous end of the capilary
What are the 5x ranges of pressures to be considered in capillary exchange when working out NFP Net Filtration Pressure?
- BHP at arterial end = 35 mmHg
- IFOP = 1 mmHg
- BCOP = 26 mmHg
- IFHP = 0 mmHg
- BHP at venous end = 16 mmHg
At what end of the capillary is their net filtration?
Arterial end
At what end of the capillary is their net reabsorption?
venous end
What is the Net filtration volume at the arterial end of the capillaries?
20L per day
What is the Net Reabsorption volume at the venous end of the capillaries?
17L per day
What is NFP on the arterial end of the capillary?
=(BHP+IFOP) - (BCOP+IFHP) =(35mmHg + 1 mmHg) - (26mmHg + 0mmHg) = 36mmHg - 26mmHg = + 10 mmHg = Blood pressure is driving fluid out of the capillary =Net Filtration pressure
Why is BHP the only part of the equation for NFP=(BHP+IFOP) - (BCOP+IFHP) to change?
As it is BLOOD PRESSURE which allows/DRIVE EXCHANGE
How do you know you have Net filtration pressure?
POSITIVE NFP number e.g. =(BHP+IFOP) - (BCOP+IFHP) =(35mmHg + 1 mmHg) - (26mmHg + 0mmHg) = 36mmHg - 26mmHg = + 10 mmHg = POSITIVE Filtration, therefore: Blood pressure is driving fluid OUT of the capillary =Net Filtration pressure
What is the NFP on the venous end of the capillary?
=(BHP+IFOP) - (BCOP+IFHP) =(16mmHg + 1 mmHg) - (26mmHg + 0mmHg) = 17mmHg - 26mmHg = - 9 mmHg = NEGATIVE filtration therefore: Blood pressure is driving fluid BACK INTO the capillary =Net Reabsoprtion pressure
How do you know you have Net Reabsorption pressure?
NEGATIVE NFP number e.g. =(BHP+IFOP) - (BCOP+IFHP) =(16mmHg + 1 mmHg) - (26mmHg + 0mmHg) = 17mmHg - 26mmHg = - 9 mmHg = NEGATIVE filtration, therefore: Blood pressure is driving fluid BACK INTO the capillary =Net Reabsoprtion pressure
What does it mean if NFP is negative?
there is NEGATIVE filtration occurring
= opposite to filtration
= REABSORPTION is occurring
= Net Rebsoprtion
What does it mean if NFP is positive?
there is POSITIVE/for filtration occurring
= greater proportion of filtration
= FILTRATION is occurring
= Net Filtration
What is Filtration?
filtration is the Pressure driven movement of fluid and solute from blood capillaries –> into interstitial fluid
What is the pressure driven movement of fluids and solute from blood capillaries –> into interstitial fluid?
Filtration
What is the main driving force oushing blood out of the capillaries?
Blood Hydrostatic pressure
What is the pressure pushing against the capillary/vessel walls?
blood Hydrostatic pressure
Which pressure is generated by the pumping action of the heart?
blood Hydrostatic pressure
What is Blood Hydrostatic pressure?
BHP = Blood hydrostatic pressure
- BHP is the pressure pushing Against the blood vessel walls
- the pressure generated by the pumping action of the heart
- is the main driving force which is pushing blood Out of the capillery
Out of all the pressures in the capillary which is pushing blood out of the capillary/promoting reabsorption, which one is the strongest?
BHP
Blood Hydrostatic pressure is the main driving force which is pushing blood OUT of the capillary
What is the pressure generated by the proteins in the interstitial fluid?
IFOP
-pulls water out via osmosis/osmotic gradient into the (more protein containing) interstitial space/adding to interstitial fluid
What drives IFOP?
The proteins in the interstitial fluid -pulls water out via osmosis/osmotic gradient into the (more protein containing) interstitial space/adding to interstitial fluid
Why isn’t IFOP larger than 1mmHg?
It is only small, as there is only a Little protein in the interstitial fluid, due to LYMPH
Why is their only a small amount of proteins in the interstitial fluid?
Due to lymph
How does lymph affect the amount of proteins in the interstitial fluid?
only allows there to be a small amount of protein in the interstitial fluid
therefore IFOP is small (close to 0)
What is Interstitial Fluid Osmotic Pressure?
- IFOP is the Proteins in the interstitial fluid
- Promotes Filtration
- PULLS fluid out of the capillaries and into the interstitial fluid
- IFOP is only small as there is only a Little protein in the interstitial fluid due to Lymph
- IFOP is opposed/reversed by BCOP
What is Reabsorption?
Reabsorption is the pressure driven movements of fluid from the interstitial fluid –> into the capillaries
What is the pressure driven movement of fluid from the interstitial fluid –> into the capillaries?
Reabsoprtion
What is the pressure generated by the large proteins in the plasma fluid?
BCOP
Which pressures have a PULL effect in capillary exchange?
osmotic pressures due to proteins in either the plasma of interstitial fluid
- IFOP
- BCOP
Which pressures have a PUSH effect in capillary exchange?
hydrostatic pressures
BHP and IFHP
What is the pressure generated by large proteins, RBCs ?
BCOP
BCOP is the pressure generated by the RBC, large blood PLASMA(inside capillaries) proteins which are too large to pass through the fenestrations/gaps between the endothelial cells of the capillary
How are RBC and certain plasma proteins able to generate Blood Colloid Osmotic pressure BCOP?
the certain proteins = LARGE proteins
the RBC, large blood PLASMA(inside capillaries) proteins are too large to pass through the fenestrations/gaps between the endothelial cells of the capillary
it is the force caused by the COLLOIDAL SUSPENSION of these large proteins in the plasma
What is the force of the large proteins causing BCOP called?
COLLOIDAL SUSPENSION of the large proteins in the plasma
What is Colloidal suspension?
a force of the large proteins in the plasma
=causes BCOP
What opposes BCOP?
IFOP
What is Blood Colloid Osmotic Pressure?
- BCOP is the large plasma proteins
- the pressure generated by the RBC and the Large plasma proteins which are too large to pass through the fenestrations/gaps between the endothelial cells of the capillary
- This is the force caused by Colloidal suspension of these large proteins in the plasma -oncotic pressure
Note: Plasma = inside the blood vessel, unless specified otherwise - BCOP PULLS fluid out of the interstitial space –> into the capillaries
What does plasma suggest?
INSIDE the blood vessel, unless specified otherwise
What PULLS fluid out of the interstitial space –> into the capillaries?
BCOP
What is osmotic pressure?
the pressure which is developed by solutes in water, generated by all dissolved colutes
What is the pressure which is developed by solutes in water, generated by all dissolved solutes?
Osmotic pressure
What is oncotic pressure?
the part of the osmotic pressure generated by larger colloidal solute components
what is the major difference between the pressures of IFOP and ICOP?
IFOP = osmotic pressure ICOP = oncotic pressure
What is the pressure which is part of the osmotic pressure generated by larger colloidal solute components?
Oncotic pressure
What is the pressure the pushes fluid from the interstitial spaces –> into capillaries?
IFHP
Which pressure is estimated 0mmHg as it is close to 0mmHg and difficult to measure?
IFHP
What is Interstitial Fluid Hydrostatic pressure?
- the fluid in the interstitial spaces
- Promotes reabsorption
- it pushes fluid from the interstitial fluid into the capillaries
- is close to 0mmHg, and therefore is difficult to measure - approximated to 0
What sort of pressure drives IFOP?
Osmotic pressure
-not oncotic pressure (the part of the osmotic pressure generated by larger colloidal solute components)
What sort of pressures drives BCOP?
Oncotic pressure(the part of the osmotic pressure generated by larger colloidal solute components) - more spesfic than osmotic pressure
What does NFP indicate?
the Directionality of movement
What indicated the directionality of movement?
NFP
-Net Filtration pressure
What are the main features of the directionality of movement in capillaries?
Whether the fluid leaves or enters capillaries depends on the BALANCE of pressures
this balance determines whether the volume of blood and volume of interstitial fluid remains steady or changes
Overall, the volume of fluids and solute reabsorbs is normally almost as large as the volume filtered : Filtered =20L per day, Reabsorbed = 17L per day
This “near equilibrium” is called Starling’s Law of the cpaillaries
What does the balance of pressures in the fluid of capillaries help determine?
Whether the fluid enters of leaves the capillaries
What is the near equilibrium of filtration and reabsorption in the capillaries called?
Starling’s Law of the Vapillaries
What is Starling’s Law of the capillaries in relation to filtration and reabsorption?
That there is this “Near Equilibrium” of the volume of fluid and solutes reabsorbed being nearly almost as large as the volume filtered
What is Blood Flow?
blood flow is the volume of blood that flows through any tissue in a GIVEN TIME PERIOD - must have time units!!! :)
Total BF =CO
What is the volume of blood that flows through any tissue in a given time period?
Blood flow = CO
What is Total Blood Flow equal to?
CO
What is CO equal to in relation to BF?
TOTAL BF = CO
What 2x things determine the distribution of CO/Total BF Blood Flow?
- Pressure Gradient
2. Resistance
What influences the distribution of total Blood Flow T.BF/CO?
- Pressure Gradient
-Drives the blood from high pressure –> Low pressure
= Larger the gradient = Larger the Blood flow - Resistance:
-resistance opposes blood flow in vessels
=Higher resistance = Smaller blood flow
-organs are therefore arranged in PARALLEL to decrease RESISTANCE (and therefore not decrease BF)
How does the Pressure gradient influence the distribution of Total Blood flow/CO?
-Drives the blood from high pressure –> Low pressure
= Larger the gradient = Larger the Blood flow
How does the Resistance influence the distribution of Total Blood flow/CO?
-resistance opposes blood flow in vessels
=Higher resistance = Smaller blood flow
-organs are therefore arranged in PARALLEL to decrease RESISTANCE (and therefore not decrease BF)
How do organs decrease the resistance (against blood flow)?
their ARRANGEMENT
-resistance opposes blood flow in vessels
=Higher resistance = Smaller blood flow
THEREFORE:-organs are therefore arranged in PARALLEL to decrease RESISTANCE (and therefore not decrease BF)
Why are organs arranged in parallel and not series?
to decrease the resistance against BF in the circuit of the body
-resistance opposes blood flow in vessels
=Higher resistance = Smaller blood flow
-organs are therefore arranged in PARALLEL to decrease RESISTANCE (and therefore not decrease BF)
What generates blood pressure?
Contraction of the ventricles, generates blood pressure (BP)
–> the hydrostatic pressure which is exerted by blood and onto the wall of the blood vessels
BP =CO x TPR
What is generated by the contraction of ventricles?
BP Blood Pressure
The contraction of the ventricles, generates blood pressure (BP)
–> the hydrostatic pressure which is exerted by blood and onto the wall of the blood vessels
BP =CO x TPR
What is the equation for BP Blood Pressure?
BP= CO x TPR
What does TPR x CO resemble?
BP
BP=TPR x CO
What is the stability of blood flow regulate by?
The factors which influence BP
BP = CO x TPR
Stability of blood flow is therefore regulated by CO and TPR
In order to MAINTAIN HOMEOSTASIS of BP and keep BP in a SMALL RANGE for exchange
-as BP DRIVES EXCHANGE
average BP = 100mmHg
What are the 2x reasons behind needing a stable blood pressure BP?
- Maintaining Homeostasis
- keeping BP in a small range for Exchange (in the capillaries) - as blood pressure DRIVES exchange in the capillaries
average Bp=100mmHg
What is the relationship between stable BP and Homeostasis?
BP blood pressure needs to have stability/be kept stable, in order to MAINTAIN HOMEOSTASIS
average BP=100mmHG
What is the relationship between stable BP and Exchange?
BP needs to be kept stable/In a small range for Exchange (in the capillaries)
-as BP DRIVED EXCHANGE in the capillaries
average BP = 100mmHg
What is SVR proportional to?
TPR
What are the 3x factors effecting TPR/SVR/Vascular resistance?
- Radius/size of the Lumen (r)
- Blood Viscosity (
- Total Blood Vessel length
How does the Radius/size of the lumen act as a factor effecting TPR/SVR/Vascular resistance?
Radius/size of the lumen changes according to need (r)
Vasodilation: Increases the size of the vessel’s/vein’s lumen, Decreases the blood pressure resistance
Vasoconstriction: Decreases the size of the vessel’s/vein’s lumen, Increases the blood pressure resistance
Why does the radius size of the venous lumen change?
Changes according to need
-of blood need to quickly divert some of the reservoir of blood upon demand
What happens during Vasoconstriction in relation to Radius/size of the venous lumen and Resistance/TPR/SVR?
Decreases the size of the vessel’s/vein’s lumen (r),
Increases the blood pressure resistance
What happens during Vasodilation in relation to Radius/size of the venous lumen and Resistance/TPR/SVR?
Increases the size of the vessel’s/vein’s lumen (r),
Decreases the blood pressure resistance
How does the Total Blood Vessel Length act as a factor effecting TPR/SVR/Vascular resistance?
Resistance of blood flow is DIRECTLY proportional to the length of the blood vessels (L)
Longer blood vessel = higher resistance
What does Resistance have a directly proportional relationship with?
Total Blood Pressure Length (L)
AND
Blood viscosity (n)
What does Total Blood pressure length have a directly proportional relationship with?
Resistance
How does Blood viscosity act as a factor effecting TPR/SVR/Vascular resistance?
Thickness of the blood (n)
-depends mostly on the RBC:plasma (fluid) volume
To a smaller extent it depends on the concentration of proteins in the plasma
DIRECTLY proportional relationship
-higher blood viscosity = higher blood pressure = high resistance
What is the thickness of the blood called and what impact does it have?
Blood viscosity (n) Impact on Resistnace
What is blood viscosity (thickness of blood) most impacted by?
RBC:plasma ratio
Smaller extent dependent on proteins:plasma ratio
(n)
What happens to blood pressure when there is an increase in blood viscosity?
Blood pressure ALSO increases when there is an increased thickness of blood, (n)
Also there is an increase in resistance. As Resistance has a directly proportional relationship to Blood Viscosity
What is Poiseuille’s Equation?
For RESISTANCE
R = 8nL/pi x r
What is Poiseuille’s equation for?
Resistance - involves all 3x factor which effect resistance (Viscosity(n), Total BV Length (L) and Radius of lumen (r)) and shows their positive and negative proportional relationships accordingly
+ 8/pi - for cylindrical measurements
Which equations illustrates the factors effecting resistance in a cylinder?
Poiseuille’s Law
R = 8nL/pi x r
-also illustrates inverse relationship of resistance and radius = use the 8 so R = 1/r^4
What is the relationship between frequency and time?
1/f = time freq= 1/T