pulmonary circulation characteristics
Download
Skip this Video
Download Presentation
Pulmonary Circulation Characteristics

Loading in 2 Seconds...

play fullscreen
1 / 9

Pulmonary Circulation Characteristics - PowerPoint PPT Presentation


  • 1016 Views
  • Uploaded on

Pulmonary Circulation Characteristics. Low Resistance /Pressure The specific structure(s) primarily responsible for the majority of control of resistance in the resting state is controversial.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Pulmonary Circulation Characteristics' - john


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
pulmonary circulation characteristics
Pulmonary CirculationCharacteristics
  • Low Resistance /Pressure
    • The specific structure(s) primarily responsible for the majority of control of resistance in the resting state is controversial.
    • Resistance more evenly distributed, but majority of resistance is normally on the arterial side (upstream) of the the capillaries.
  • Thin-walled arterial system

(relatively little smooth muscle)

  • Anatomical considerations
    • Vessels are surrounded by bags of gas and flexible interstitial fluid-filled regions
    • No true arterioles??
    • Alveolar and extra-alveolar vessels respond to conditions differently
influences on resistance
Neural/Humoral: all the same players as in the periphery (but less effective) and a few with more specific actions

Serotonin: Arterial side vasoconstriction

Histamine: Venular side vaso(veno)constriction

***venous side can become dominant resistance

Intravascular Pressure R 1/P

recruitment (primary)

distension

Pulmonary

Circulation

Influences on resistance
slide3

300

200

Increasing

Arterial Pressure

(cmH2O/L•min-1)

Pulmonary Vascular Resistance

100

Increasing

Venous Pressure

0

10

20

30

40

Arterial or Venous Pressure

(cm H2O)

Perfusion

influences on resistance4

Pulmonary

Circulation

Influences on resistance
  • Neural/Humoral:all the same players as in the periphery (but less effective) and a few with more specific actions
    • Serotonin: Aretrial side vasoconstriction
    • Histamine Venular side vaso(veno)constriction
  • Intravascular Pressure R 1/P
    • recruitment (primary)
    • Distension

***Thus, cardiac output is considered to be the primary determinant of pulmonary vascular resistance

  • Lung volume
slide5

120

100

Vascular Resistance

(cmH2O/L•min-1)

80

60

200

50

100

150

Lung Volume (ml)

influences on resistance6

Pulmonary

Circulation

Influences on resistance
  • Lung volume
    • Low Volume: extra-alveolar vessels are smaller, capillaries more open
    • High Volume: extra-alveolar vessels are pulled open; capillaries become defromed by stretch (more oval; higher resistance)

* Lung volume effects on extra-alveolar vessels is lost with positive pressure ventilation.

  • PO2: Local Control Decreased PAO2 causes vasoconstriction. Advantage: blood is shunted away from poorly ventilated alveoli.
  • Surrounding Pressure
    • Alveolar
    • Interstitial (<0)
slide7

The Starling Resistor Concept

Pulmonary

Circulation

slide8

Zone 1

PA>Pa>Pv

Zone 2

Pa>PA>Pv

Distance

Zone 3

Pa>Pv>PA

Blood Flow

Pulmonary

Circulation

Arterial (Pa)

Alveolar (PA)

Venous (Pv)

slide9

Pulmonary Artery

Pulmonary

Circulation

60

Pulmonary Arterial

50

Catheter Tracing

40

mmHg

30

20

10

0

Left Atrial Pressure Tracing

Pulmonary Capillaries

Left

Atrium

Pulmonary Vein

ad