Arterial System and Blood Pressure

Arterial System and Blood Pressure

Arteries serve as hydraulic filter

Arterial System and Blood Pressure

Arterial System and Blood PressureArteries Are Compliant Tubes

Reduced compliance is a manifestation of:• ↑Collagen content• ↓Elastin contentSlop =

Compliance

Arterial System and Blood PressureFactors that determined Arterial Blood Pressure

Mean Arterial Pressure(MAP)

3P - P P P ds

__

da

Arterial System and Blood PressureChange in complianceChange In Stroke Volume

Arterial System and Blood PressureArterial pulse

pressure

Arterial System and Blood PressureArterial pulse pressure

Why Pulse pressure change itself shape along the artery tree?

Likely;1.Decreased compliance of distal

arteries2.Reflective waves, particularly from

arterial branch point

Arterial System and Blood PressurePulse Wave

Speed: Aorta 3-5 m/s Large arteries 7 –

10 m/s Small arteries 15 -

35 m/s

Arterial System and Blood Pressure

Effects of Pressure on Vascular Resistance and Tissue Blood Flow

The reasons:1. Increases the force that pushes blood2. Distends the vessels at the same time

Arterial System and Blood PressureChanges in systolic, diastolic, and mean arterial

pressures with age

Veins and Their Functions

• Right Atrial Pressure (Central Venous Pressure)Regulated by a balance between

(1) The ability of the heart to pump blood out of the right atrium and ventricle into the lungs

(2) The tendency for blood to flow from the peripheral veins into the right atrium.

Venous Pressures:

Veins and Their Functions

• Peripheral Venous Pressures

Venous Pressures:

Veins and Their Functions

Spleen (as much as 100 ml) Liver (several hundred ml) large abdominal veins (as much as

300) Venous plexus beneath the skin

(several hundred ml) Heart (~ 50 -100 ml) Lungs (~ 100 -200 ml)

Specific Blood ReservoirsReference point for circulatory pressure