Cardio

• blood flows from


  high to low pressure
• heart works to keep arterial pressure ______ than venous

  higher
• Cardiac Output (CO)


  volume of blood pumped by each of the ventricles per minute
• formula for cardiac output


  CO = HR x SV

  
  

  vol/min = L/min = bpm x vol/beat
• capacitance


  degree of active constriction of vessels (holding capacity)
• ARTERIAL PRESSURE


  a function of change in volume since its capacitance is fairly constant
• arterial pressure is a function of a change in _________ since its capacitance is fairly ________

  change in volume, capacitance is fairly constant
• when blood is ejected from the ventricles during systole there is a/an (increase/decrease) in ______________. this causes the arteries to?

  increase in volume

  
  

  distend (stretch) slightly and increase in pressure due to the surge of blood flow
• When the volume increases during systole what happen to the arteries ?


  distend (stretch) slightly, increase pressure due to the surge of blood flow

  
  

  1/3 of blood in arteries flows out
• When the volume increases during diastole what happen to the arteries ?

  the arteries passively recoil due to their elastic properties, pushing more blood out
• Mean arterial pressure (MAP)


  Average effective pressure that drives blood through the systemic organs
• equation for pulse pressure

  SBP-DBP
• Total Peripheral Resistance (TPR)

  overall resistance to flow through the entire systemic circulation
• what is the formula for Mean arterial pressure approximation ?


  ⅓ systolic blood pressure (SBP) +⅔ diastolic blood pressure (DBP)
• what is the formula for Pulse pressure?


  PP = systolic blood pressure (SBP) - diastolic blood pressure (DBP)
• What is the typical /normal human blood pressure?

  120/80 mmHg
• what is sphygmomanometer?


  blood pressure cuff used to measure blood pressure through auscultation
• what is auscultation?

  taking a BP by listening for artery sound
• What are Korotkoff sounds?

  "tapping" sounds that a partially occluded artery makes due to turbulent blood flow - systolic BP

  
  

  diastolic BP - when Korotkoff sounds are no longer heard
• How to take take blood pressure with the pressure cuff?

  1. inflate the pressure cuff around upper arm

  
  

  2. occlude the brachial artery to the point of collapse

  
  

  3. slowly release

  
  

  4. When pressure is low enough to allow some blood pass, intermittent turbulent flow is heard as a tapping sound
• systolic blood pressure


  pressure where the first Korotkoff sound are heard

  
  

  (peak pressure generated by artery )
• diastolic blood pressure


  Pressure where Korotkoff sounds are no longer heard
• What do we hear during auscultation?


  It's not the heart beating it the blood trickling through the blood vessels as you decrease blood pressure allow the blood to go through
• what causes vessels to resist movement?

  friction caused by blood flow
• Vascular resistance


  measure of how hard it is for blood to flow through a vessel
• How is blood flow achieved ?

  differences in pressure
• flow causes friction between _____ and _____ _____, causing vessels to resist fluid movement.

  blood and vessels walls
• What is the formula for blood flow ?


  Flow=△Pressure/Resistance

  
  

  Q=△P/R

  
  

  -Q = flow rate (Vol/time)

  -Delta p = pressure difference (mmHg)

  -R= resistance (mmHg x time / vol)
• What is the purpose of resistance?

  used to alter the flow rate
• Resistance equation


  R = 8Lη/πr4

  
  

  L = Length

  η = fluid viscosity

  r = radius of the vessel
• What happen is we increase r in the resistance formula ?


  r = radius

  
  

  increased radius = reduced resistance = increased blood flow
• Poiseuille's equation


  Q = ΔPπr4/8Lη
• How is the Poiseuille's equation achieved ?


  combines blood flow and resistance equation (Q=△P/R)
• How is flow rate regulated?

  changes in the radius of the vessel
• How is pressure in blood vessels determined ?

  1. Volume of blood in vessel (capacitance)

  
  

  2. How easily the vessel can be stretched (compliance)
• What is the formula for compliance ?


  C = ΔV/ΔP
• Compare and contrast veins and arteries in retrospect to compliance and capacitance.

  vein

  1. more compliant

  2. more capacitance

  3. not elastic

  
  

  arteries

  1. less compliant

  2. less capacitance

  3. elastic
• How can you increase volume in arteries?

  Increase:

  - SV

  - CO

  - HR

  - arterial resistance
• How can you increase volume in veins?


  1. decrease in the right heart pumping

  2. change in body position from reclining to upright
• How to decrease volume in vessels ?

  1. decrease inflow

  
  

  2. increase outflow