Question

Describe the several different factors controlling the rate and velocity of blood flow through vessels. Also, explain how the heart and blood vessels assure one-way blood flow through the heart, lungs, and body.

Answer 1

Factors controlling the Rate and velocity of blood flow:

Cardiac output:

Rate and Velocity of blood flow is directly proportional to cardiac output.If the cardiac output increases the rate and velocity of blood flow is increases, The cardiac output decreases the rate and velocity of blood flow decreases.

Cross sectional area of blood vessels :

Rate and Velocity of blood flow is inversely proportional to the cross sectional area.If the cross sectional area of the blood flow is increases the rate and velocity of blood flow is decreases.If the cross sectional area decreases the velocity of blood flow increases.

Viscosity of blood:

  The rate and velocity of blood flow is inversely proportional to the viscosity of blood.If the viscosity of blood flow increases i.e. friction produced by the blood against the arteries. Rate and Velocity get decreased. If the viscosity decreases the rate and velocity of blood flow get increased.

Blood volume :

   Blood volume is directly proportional to the rate and velocity of blood flow. If the blood volume is increases the rate and velocity is also increases and the blood volume is decreases the rate and velocity of blood flow is decreases.If the volume of blood is higher in the body the velocity and flow rate of blood is higher.

Compliance :

It is the property of blood vessels , that the elastic deformation of blood vessels. The compliance increases the rate and velocity of blood flow get decreases. If the compliance decreases the rate and velocity get increases.

In heart, valves is present it prevents the backflow of the blood it allows the blood in one way direction through the heart.

The blood reaches the lungs via pulmonary artery for oxygenation. From the pulmonary artery the blood transfers to the pulmonary vein due to pressure produced by the heart to allows the blood flow through the lungs in one direction.

In the body, the blood travel from the higher atrial pressure to the lower atrial pressure it allows the blood to flow in one direction.