PHYSIO FINAL

• Gardner is ...


  Wider
• Jet is....


  Vessel constriction
• The pressure gradient provides...


  The driving force that keeps blood moving from higher to lower pressure gradient
• What generates pressure gradient?

  Heart (contraction)
• What does flow depend on?

  1) amount of blood
• What are three important sources of resistance?

  1) Blood Viscosity

  2) Total blood vessel length

  3) Blood vessel diameter
• Blood viscosity is...


  Thickness of blood
• Total blood vessel length is...

  How far blood has to go
• Blood vessel diameter is

  How big the blood vessel is
• Resistance is


  1) Things that oppose flow

  2) Radius, Viscosity, Local activity and more ato and hormones
• As resistance goes up it increases...

  Flow decreases if nothing changes
• Radium is easily...


  Adjusted and small changes in radius lead to big changes in flow
• Vasoconstriction:


  As radius decreases, flow decreases
• Vasodilation:


  As radius increases, flow increases
• Blood viscosity:


  The thicker the blood, slower the flow
• Which hormone could lead to higher viscosity?

  Erythropoietin
• How much blood goes out depends on?

  1) Cardiac Output

  2) BP

  3) Resistance
• Stroke volume is regulated by which three variables?

  1) EDV (End diastolic volume)

  2) Total peripheral resistance

  3) Contractility
• EDV :


  Volume or blood in the ventricles at the end of diastole

  (Called preload)

  (Stroke volume increases with increased EDV)
• Total Peripheral Resistance


  Frictional resistance in the arteries

  (Afterload)

  (Inversely related to stroke volume)

  (As resistance increases, stroke volume decreases)
• Contractility


  Strength of ventricular contraction

  (SV increases with increase in Contractility)
• Autoreggulation Blood Flow


  Will automatically dilate blood vessels at the active tissue - this increases flow to those tissues
• negative feedback


  maintains homeostasis
• Blood vessels usually...


  are innervated by sympathetic neurons (these release NE onto blood vessels)
• Generally, NE causes ?

  Vasoconstriction
• a1 receptors


  smooth muscle contraction/constiction
• B2 receptors


  smooth muscle relaxation/dilation
• What have B2 receptors so during flight.fight they dilate?

  - Skeletal muscle arteries

  - Lung arteries

  - Coronary circulation
• systolic pressure


  peel partial pressure during ventricular systole
• diastolic pressure


  minimum arterial pressure during diastole
• pulse pressure


  difference between systolic and diastolic pressure
• Mean Arterial Pressure (MAP)


  the perfusion pressure seen by organs in the body
• As resistance of any form goes up/increases...


  MAP increases
• Map pressure depends on:

  1) Fluid

  2) Fluid loss or bleeding out

  3) An increase in cardiac output
• Fluid...


  as blood volume increases, MAP increases such as drinking gallons of water at once or retaining water due to high salt diet
• Fluid loss or bleeding out...

  decreases MAP
• An increase in Cardiac Output can...

  increase MAP
• Baroreceptor reflexes...


  adjust cardiac output and peripheral resistance to maintain normal arterial pressure.
• Automatic in response to BP changes Baroreceptors (measure pressure) are ...

  stretch-sensitive mechanoreceptors located in the walls of major blood vessels
• Stretch receptors in walls of...

  1. Carotid sinuses

  2. Aortic Sinuses

  3. Right Atrium