Laws Flashcards
Starling’s law of the heart: the energy liberated with each contraction of the heart is a function of the __________ ____________ _____________ _____________; increased preload causes increased end-diastolic volume (or pressure), which increases the force of ventricular contraction.
length of the fibers composing its muscular walls
Starling’s law of the heart: the energy liberated with each contraction of the heart is a function of the length of the fibers composing its muscular walls; increased preload causes increased __________ __________, which increases the force of ventricular contraction.
end-diastolic volume (or pressure)
Starling’s law of the heart: the energy liberated with each contraction of the heart is a function of the length of the fibers composing its muscular walls; increased preload causes increased end-diastolic volume (or pressure), which _________ the force of ventricular contraction.
increases
Name the LAW:
The pressure applied at each point under a bandage is proportional to (N × T)/(R × W)
- N is the number of bandage layers
- T is the bandage tension
- R is the radius of curvature of the body part being bandaged
- W is the width of the bandage material under tension
Laplace’s Law (Bandage)
Laplace relationship to Cardio
Systolic Wall Stress (SWS) = (Systolic pressure x Ventricular radius) / Ventricular wall thickness
σ = LVP × R/h, where:
- σ: Is the myocardial wall stress
- LVP: Is the intraventricular pressure
- R: Is the radius of curvature
- h: Is the wall thickness
According to Laplace’s Law, systolic wall stress is directly proportional to the pressure inside the ventricle (systolic pressure) and the radius of the ventricle, while inversely proportional to the thickness of the ventricular wall, meaning that a larger chamber radius or higher pressure leads to increased wall stress, while a thicker wall reduces it; essentially, the formula for calculating wall stress using Laplace’s Law is: Wall Stress = (Pressure x Radius) / (2 x Wall Thickness).
Laplace’s law: tension or stress on the cardiac ventricular walls is proportional to the _____________ _________________ and internal radius and inversely proportional to the wall thickness.
intraventricular pressure
Sphere it is most simply expressed as:
average circumferential wall stress = (pressure × radius of curvature of the wall) ÷ (2 × wall thickness); more complex equations describe ellipsoidal or other shapes.
Laplace’s law: tension or stress on the cardiac ventricular walls is proportional to the intraventricular pressure and ______________ _____________ and inversely proportional to the wall thickness.
internal radius
Sphere it is most simply expressed as:
average circumferential wall stress = (pressure × radius of curvature of the wall) ÷ (2 × wall thickness); more complex equations describe ellipsoidal or other shapes.
Laplace’s law: tension or stress on the cardiac ventricular walls is proportional to the intraventricular pressure and internal radius and inversely proportional to the _____________ ________________.
wall thickness
Sphere it is most simply expressed as:
average circumferential wall stress = (pressure × radius of curvature of the wall) ÷ (2 × wall thickness); more complex equations describe ellipsoidal or other shapes.
According to Laplace’s law, the pressure applied at each point under a bandage is proportional to
(N x T)/(R × W)
- N is the number of bandage layers
- T is the bandage tension
- R is the radius of curvature of the body part being bandaged
- W is the width of the bandage material under tension
Bernoulli’s principle states that
states that as the speed of a fluid increases, the pressure decreases.
Medically as blood flows through a narrowing vessel, its velocity increases, which leads to a corresponding decrease in pressure, demonstrating an inverse relationship between blood flow velocity and pressure within the circulatory system.
Essentially, faster blood flow results in lower pressure at that point, and vice versa, allowing us to understand how blood pressure changes in different parts of the circulatory system, particularly in areas with varying vessel diameters like narrowed arteries due to plaque buildup.
Poiseuille’s law
Poiseuille’s law:
Q = πΔP(r^4)/8ŋl
- Q is the rate of flow
- ΔP is the pressure difference between the ends of the airway
- r is the radius of the airway
- ŋ is the viscosity of the gas
- l is the length of the airway
Stenotic nares and abnormal intranasal turbinate anatomy cause stertorous breathing in clinically symptomatic dogs, suggesting increased resistance to nasal airflow. The overlong soft palate projects into the larynx and causes stridor in symptomatic dogs. Breathing patterns assessed by tidal breathing flow-volume loops were consistent with a fixed-type upper airway obstruction in the majority of brachycephalic dog studies. A smaller number of dogs had a non-fixed upper airway obstruction In both cases, the increased resistance to airflow is caused largely by a decrease in airway radius as illustrated by Poiseuille’s law, with flow being proportional to the radius of the airway to the fourth power.
Which formula is this:
SWS = P sys x ventricular radius/ ventricular wall thickness
LaPlace formula:
LaPlace formula
SWS = P sys x ventricular radius/ ventricular wall thickness
Systolic wall stress (SWS)
Systolic pressure (P sys)
Mean arterial blood pressure (MAP) is a function of ____ , ____ and ____ .
cardiac output, vascular resistance (R), and atrial pressure (AP).
MAP = (QxR) + AP
Cardiac output (Q) is the product of ____ and ____ .
stroke volume and heart rate
CO = SV x HR
Vascular resistance cannot be measured directly but can be calculated by knowing ____ , ____ and ____ ?
- Q, MAP, and AP
- Formula:
R = (MAP - AP) /Q
