Cardiovascular System Overview

Cardiovascular System - Circulatory System

• The cardiovascular system is a closed system of the heart and blood vessels.
• The heart pumps blood, and blood vessels allow blood to circulate throughout the body.
• Blood is not a simple fluid; it has cells that impact flow, especially in narrow passages.

Cardiovascular System - Functions

• Blood carries oxygen, nutrients, and vital substances to cells.
• Blood removes metabolic waste products from cells.
• Blood is pumped through the circulatory system by the heart, exiting through arteries and returning to the heart via veins.

Cardiovascular System - Fluid Motion

• The flow of blood is studied by French physician L.M. Poiseuille.
• This study details the principles governing fluid flow and applies them to blood flow in the circulatory system.

Cardiovascular System - Blood Flow

• Blood flows from the upper body to the lungs and vice-versa to become oxygenated.
• Deoxygenated blood from the lower body is transported to the lungs, while oxygenated blood returns to the upper body.
• The same process happens in reverse when the deoxygenated blood from the upper body flows to the lungs.

Cardiovascular System - Continuity Equation

• The continuity equation relates velocity and cross-sectional area of blood flow in the arteries and capillaries.
• The product of the cross-sectional area and velocity remains constant.
• A larger cross-sectional area corresponds to a smaller velocity and vice versa.

Cardiovascular System - Bernoulli's Equation

• Bernoulli's equation describes the relationship between velocity, pressure, and elevation in fluid flow.
• It follows from the law of energy conservation, and in the absence of friction the sum of the terms in the equation remains constant during altered flow patterns.
• Bernoulli's equation considers pressure, kinetic energy per unit volume and potential energy per unit volume, all of which remain constant in fluid flow.

Cardiovascular System - Blood Pressure

• Blood pressure is relatively constant throughout the body in the horizontal position (laying down).

• Velocities and height differences between body parts in the horizontal position are small, so the terms in Bernoulli's equation for velocity and height can be disregarded.

• When the body is vertical (standing), height difference between body parts significantly impacts blood pressure.

• The pressure is not constant across the body.

Cardiovascular System - Effect of Acceleration on Blood Pressure

• High upward acceleration causes a decrease in blood pressure in organs at higher altitudes (head).
• High downward acceleration causes an increase in blood pressure in organs at higher altitudes.

Cardiovascular System - Viscosity and Poiseuille's Law

• Fluid flow (blood flow) is influenced by viscous friction between molecules in the fluid.
• Viscosity (η) affects fluid flow.
• Poiseuille's law relates fluid flow to pressure difference, viscosity, tube radius and length.

Cardiovascular System - Turbulent Flow

• Flow becomes turbulent with eddies and whirls when the fluid velocity exceeds a critical point.
• The Reynolds number (R) relates to flow velocity, fluid density and pipe diameter.
• Low Reynolds numbers usually indicate a laminar flow, while high numbers indicate a turbulent flow.

Explore the complexities of the cardiovascular system, including the roles of the heart, blood vessels, and blood. Understand how blood flow is regulated and the functions of the circulatory system. This quiz encompasses key principles of fluid motion and blood circulation.