01. Bridging CVRS to CPP

Created by

Evie T

Cards (16)

pressure = flow x resistance
fluids move by convection down a pressure gradient
cardiac cycle = complete cycle of contraction and relaxation of the heart with each heart beat.
allows for a pressure gradient to eject blood from the ventricle (stroke volume).
Wiggers diagram = allows us to visualise the volume and pressure changes occurring in different locations during each phase of the cardiac cycle
respiratory cycle = complete cycle of inspiration and expiration of a single breath
allows generation of a pressure gradient to inspire the tidal volume
intrapleural pressure couples the chest wall and diaphragm to the lung tissue
enables muscle work to increase volume of lungs and generate the pressure gradient for inspiration.
reduction in lung volume increases alveolar pressure to generate the pressure gradient for expiration
resistance to flow work in opposition to the pressure gradient
increasing pressure = increased flow
increasing resistance = decreased flow
most important factor that controls resistance is radius^4
major site of resistance in the arterial system is the arterioles
innervated by sympathetic nerves with low level of background activity.
induces vasoconstriction, so have more background tone.
total peripheral resistance = sum of all resistances in the different blood vessels
if TPR increases, blood pressure increases.
energy is lost overcoming resistance so blood pressure upstream increases (aorta) and blood pressure downstream reduces (capillaries)
amount of flow is proportional to size of pressure gradient, and inversely proportional to resistance.
for laminar flow, flow = pressure / resistance
cardiac output = heart rate x stroke volume
stroke volume = end diastolic volume - end systolic volume
cardiac output = arterial blood pressure / total peripheral resistance
minute ventilation = tidal volume x respiratoy frequency
when gases move by diffusion, they move down their concentration gradients, and this is the partial pressure gradient