Modifying heart function Flashcards
What does increasing cardiac tension lead to?
Increase Ca2+ sensitivity of troponin C
Increase Ca2+ release from the SR
Define Frank Starling’s law?
The longer the fibre length, the stronger the contraction
This is an ionotropic effect
Complete equation:
CO=
BP=
Pulse pressure=
Mean arterial pressure=
Stroke volume=
Poiseuille’s equation Flow=
Ohms law Flow=
Write equation for heart rate?
Heart rate= CO/SV
Write an equation for total peripheral resistance?
TPR=BP/CO
Write an equation for resistance?
pressure/flow
Define preload?
Ventricular stretch at end diastole
Define afterload?
Pressure that the chambers need to generate to eject blood out of heart
What affects pre-load?
Venous blood pressure
Rate venous return
What affects afterload?
Vascular resistance
Pulmonary vascular resistance
When does pre/after load occur?
Preload- Diastole
Afterload- Systole
Is preload volume or pressure?
Volume
Afterload- pressure
What is preload dependent on?
Amount ventricular filling
What is afterload dependent on?
Arterial blood pressure
Vascular tone
Define systole? Range?
Maximum arterial pressure during contraction of left ventricle
Max BP inside arteries
Occurs left ventricle contracted
90-120
Define diastole? Range?
Minimum arterial pressure during relaxation of left ventricle
Min BP inside arteries
Occurs left ventricle relaxed
60-80
Does diastole or systole undergo fluctuations?
Diastole
What increases with age diastole or systole?
Diastole
Systole decreases with age
What factors affect heart rate?
Hormones
Age
Fitness lvls
Autonomic innervation
Smoke
What factors affect stroke volume?
Heart size
Fitness lvls
Gender
Contractility
Duration contraction
Preload
Afterload (resistance)
How calculate stroke volume?
SV= EDV-ESV
