Chapter 15 & 16 - Veins & Microcirculation Handout Flashcards
Total amount of blood that can be stored in a given portion of circulation per ml of mercury rise in pressure.
Compliance
Ability of a certain vessel type to accomodate blood and change its caliber.
Distensibility
Mechanism that compensates when there is an increase in blood pressure volume
Stress Relaxation or Delayed Compliance
Pressure in the RA where blood from all peripheral veins empty
Central venous pressure (CVP) or R Atrial pressure
Two major factors that affects pulse pressure
- Stroke volume output of the heart.
- Compliance (total distensibility) of the atrial tree
Less important factor:
Character of ejection from the heart during systole
What is the normal value of the right atrial pressure?
0 mm Hg
Normal value of arterial pressure?
100 mm Hg
True or False:
The heart acts as a feedback regulator of pressure at the tricuspid valve.
True
True or False:
60% of all the blood in the circulatory system is usually in the arteries.
False.
usually in the VEINS
Korotkoff sounds is named after ______. A russian physician who described them in 1905.
Nikolai Korotkoff
It is the average ofthe arterial pressures measured millisecond by millisecond over a period of time.
Mean Arterial Pressure
Other name for venous pump
Muscle pump
True or False:
The venous system serves as blood reservoirs for the circulation.
True
Specific blood reservoirs
Spleen
Liver
Large abdominal veins
Venous plexus beneath the skin
A “specific blood reservoir” which decrease in size sufficiently to release as much as 100 millimeters of blood into other areas of circulation.
Spleen
True or False:
Heart and lungs as blood reservoirs.
The heart shrinks during sympathetic stimulation thus contribute 50-100 ml of blood, the lungs can contribute another 100-200 ml when the pulmonary pressures decrease to low values.
True
Two areas in the spleen for storing blood.
- Venous sinuses
2. Pulp
It is a special reservoir in the spleen that contains large quantities of concentrated red blood cells.
Red pulp of the spleen
An area in the spleen that manufacture lymphoid cells
White pulp of the spleen
Main purpose of circulatory system
- Transport of nutrients to cell
2. Removal of cell excreta
Intermittent flow of blood in the capillaries through the contraction of the metarteriole and precapillary sphincter.
Vasomotion
What can pass through the tight junctions in the brain?
Only water, O2 and CO2
True or False:
Blood usually does not flow continuously through the capillaries.
True
Most important factor for degree of opening and closing in vasomotion.
Oxygen concentration.
Low o2 in tissues –> more frequent and prolonged flow of blood
