Structure and Function of Cardiac System Flashcards
How does blood flow
Systemic-pulmonary-systemic
What is the circulatory system composed of
Vessels, fluid, pump
What’s the difference between arteries compared to veins
Thicker, more pressure, no valves
What does blood flow depend on
pressure, resistance, velocity, compliance
Is there more or less resistance in smaller and highly viscosis
Higher
Does velocity decresease or increase as blood moves from the aorta
Decresases
What is vascular compliance
How well the cessel can accommodate for a change in volume
What does the left side of the feart do
Oxygenated, thick , to the body, high pressure
What does the right side of the heart do
low pressure, to the lungs, deoxygenated
What is the blood flow through the heart chambers
body-RA-RV-lungs-LA-LV-body
What does the pericardium do
Protect against inflmmation, dieplacement, and contains pain receptors and changes BP and HR
What is the myocardium
Thick muscle layer
What does the endocardium do
Internal lining, connects with vessels
What is diastole
Relaxation when the chambers fill
What is systole
The contraction
What does a murmur sound like
Fish nosie
What does the LAD supply
Most of the left side of the heart
What do the coronary vessels do
supply the heart with blood
When is coronary blood flow higher
Diastole
Does the heart get good blood flow when it is racing
No because there is less diastole which means less blood flow to the coronary arteries
What is collateral circulation
Arterial anastomoses, normal
What should you know about collateral circulation
Happens slowly when occlusion is happening, greater chance of surviving a MI
What does cardiac muscle depend on
ATP energy
What is the enfery used for in the heart
Muscle contraction and elctrical excitation
What is the cardiac output
Volume of blood ejected by a ventricle in 1 minute
What is the normal cardiac output
5L/min
How do you calculate cardiac output
HR*SV
What are the factors that affect cardiac output
Pre/afterload
What are the extrinsic control of the heart
ANS, hormones
What are the intrisic control of the heart
Rhythm, rate, force, EDV
What is the end diastolic volume
The amount of blood left in the body
What does the SNS do to the heart
Increases everything
What does the PNS do to the heart
Decreases HR
What are some endorcine responsers
Thyroid hormone, epi
What is stroke volume
Amount of blood ejected by the ventricl with EACH CONTRACTION
How does venous return effect SV
If it increases so does SV, likewise for decreasing
What is preload
The stretch of the heart tissues right before contration
What influences preload
The amount of venous return, and the blood left over
How does preload affect SV
If increased it also increases
What does an increased preload mean
Stronger contraction
What happen when the HR increases
Fillinf time is reduced, icraesed pressure
What will these factors do to preload: increased pressure, vasoconstriction, increased blood volume, decreased heart rate
Increase
What will these factors to to preload: decreased BP, blood volume, hypertrophy, gravity
decrease
What is afterload
The FORCE needed to eject blood from the heart
What is afterload dependant on
CP
What does hypertension do to afterload
Increases
What is the ejection fraction
Fraction of blood ejected by the left ventricle during contraction
How do you calculate ejection fraction
SV/EDV
What does sympathetic stimulation do to EF
Increase
What does ventricular failure do to EF
Decrease
What is EF an important factor of
CHF
What is cardiac reserve
The ability of the heart to increase output in RESPONSE to increased demand
Do trained athletes have good cardiac reserve
Yes
Why do lazy people get SOB faster than athletes when running
The heart is racing faster so the heart can’t fill as fast so there is less O2
What can alterations in cardiac function look like
increased HR, SOB, fatigue, distress, chest pain
What are some nursing indactations for altered cardiac function
O2, EKG, sit them up, anti coag
