Vascular System. Flashcards
Blood Vessels. Venous Return. Vascular Shunt Mechanisms. AVO2 Difference. Bohr Shift.Redistribution of Blood. Starling's Law.
List the Characteristics of Arteries.
Narrow Lumen.
No Valves.
High Pressure.
Thick, Muscular Walls.
Smooth Inside Layer.
What is the Function of Arteries?
Take blood away from the heart.
List the Characteristics of Veins.
Wide Lumen.
Valves,
Low Pressure.
Thin Walls.
No Smooth Layer.
What is the Function of Veins?
Bring blood towards the heart
Define Valves.
Prevent the backflow of blood.
Define Venous Return.
Blood returning back to the heart in the veins.
List the Venous Return Mechanisms.
Pocket Valves.
Skeletal Muscle Pump.
Respiratory Muscle Pump.
Smooth Muscle.
Suction Pump at Right Atrium.
Gravity.
Describe Pocket Valves.
Allow one-way blood flow, and close to prevent back flow.
Describe Skeletal Muscle Pump.
As muscles contract.
Squashes the veins.
Increases pressure in the vein.
Forces blood out towards the heart.
Describe Respiratory Muscle Pump.
Changes in thoracic and amdominal pressure when breathing in and out.
Squash the surrounding veins.
Increases pressure in the vein.
Forces blood out towards the heart.
Describe Smooth Muscle.
Veins have thin walls, but the muscle that is there can contract/twitch to increase pressure
Describe Suction Pump at Right Atrium.
As right atrium relaxes, this pressure change ‘sucks’ blood in.
Describe Gravity.
If above the heart.
During exercise, there is an increase in Venous return. This means…
Greater filling of the heart.
Cardiac muscles stretch more.
The resulting force of contraction is increased.
Increased stroke volume/ejection fraction.
List Vascular Shunt Mechanisms.
Vasodilation.
Vasoconstriction.