C&R Phys Flashcards
1.Isovolumic (Isovolumetric)Contraction Phase:
•Time between ___ valves closing and ____ valve opening therefore both sets of valves are closed
• First heart sound occurs when ___ valves close.
• Onset of this phase linked to beginning of ventricular _____ (QRS—linked to peak of R)
• Associated with ______ volume of blood in ventricles (end diastolic volume or EDV)
• Linked to “c” wave of atrial pressure
• Ends with aortic valve opening which begins the next phase
AV
aortic
AV
systole
highest
2.Ejection Phase:
•Time between the opening of aortic (and pulmonary) valve and the closing of the
aortic (and pulmonary) valve.
•Aortic pressure increases from 80 mmHg to 120 mmHg during this phase (BP is highest)
•Rapid ejection of blood occurs in the first 1/3 of ejection phase and ___% of blood volume is ejected
• Slow ejection is the final ___% of the blood volume ejected and takes the remaining 2/3 of ejection time.
•Ends when ______ valves close
•2nd heart sound occurs when _________
valves close
70%
30%
semilunar
semilunar
- Isovolumic (Isovolumetric) Relaxation Phase:
•Time between aortic valve closing and AV valves opening therefore both sets of valves are closed
• 2nd heart sound (semilunar valves close)
• Associated with end of ___wave on ECG
•Ventricular volume following ejection (end systolic volume or ESV—______ ventricular volume)
•Associated with “__” wave of atrial pressure
•Aortic pressure is decreasing back to 80 mmHg but the small increase after the aortic valve closes is called an ______ or dicrotic notch—caused by a small amount of backflow from the closure of the aortic valve.
T
lowest
v
incisura
4.Rapid Inflow (Filling) Phase:
•First ____of filling time— blood accumulating in the atria pushes the AV valves _____ and blood rapidly fills the ventricles
1/3
open
- Diastasis Phase:
•Second ___ filling time—blood returning to the heart continues to pass through to
ventricles
1/3
- Atrial Systole Phase:
•Last 1/3 filing time
•Atria contracts (__ wave on ECG) giving the last push of blood into the ventricles.
•Accounts for about __% of total ventricular volume
P
20
regulation of cardiac output:
1. Intrinsic Regulation: Frank-Starling Law- deals with relationship between ____ and Q.
•_____ _______ has the biggest impact on maintaining and increasing Q
•Other intrinsic factors that regulate Q are ___, SV and contractility.
preload
Venous Return (VR)
HR
2. Extrinsic Regulation: Autonomic NS A.Parasympathetic NS •\_\_\_\_\_\_ nerve primarily ↓ HR •Can ↓ SV •\_\_\_\_ binds to specific cholinergic (M2 muscarinic) receptors to \_\_\_\_ HR
B.Sympathetic NS
•Sympathetic nerves ↑ HR and ↑ SV
•_________ and Epinepherine
bind to specific (β1) receptors
Vagus
ACh
slow
Norepinepherine
normal conduction of the heart is:
SA node–>___ ____ –>bundle of his–> R and L bundle branches–> ______ fibers
AV node
purkinje
•S-A node-Dominant pacemaker with an
intrinsic rate of ___-__ beats/minute.
•A-V node-Back-up pacemaker with an
intrinsic rate of ___-___ beats/minute.
•Purkinje fibers-Back -up pacemaker with
an intrinsic rate of 15-40 beats/min.
70-80
40-60
velocity of action potentials: •SA node—0.3 to 0.5 m/sec •AV node—0.02 to 0.05 m/sec •Purkinje fibers—1.5 to 4.0 m/sec •Myocardium—0.3 to 0.5 m/sec
- what has the most rapid conduction rate?
purkinje fibers (.06 sec??)
- P wave =_____ _______
- ____ ______=Ventricular depolarization
- __ wave= Ventricular repolarization
Atrial depolarization
QRS Compex
T
____ ______ represents the interval between atrial depolarization and the initiation of ventricular depolarization so the AV node
delay
PR Interval
__ _______ represents the beginning of
ventricular depolarization through the end of ventricular repolarization
QT Interval
__ ______ represents the time between the end of ventricular depolarization and the beginning of ventricular repolarization
ST Segment
the Three Layers of a blood vessel are:
1._____ _____- contains the endothelium that lines the lumen. Smooth layer that
minimizes friction.
2.Tunica media—circular smooth muscle and elastic fiber. Thickest layer. Regulates __________ and ___________
3. Tunica externa (adventitia)—collagen fibers that reinforce the vessel. Contains nerve fibers, lymph vessels, and blood vessels (____ ______) so the exterior of
the vessel is nourished.
Tunica intima
vasodilation and vasoconstriction.
vasa vasorum
- Distensibility is the ability of the blood vessel to stretch, expand, or dilate.
- Walls of the veins are __ times more distensible than arteries.
- Compliance is the ability of the blood vessel to stretch etc. but also includes the ______ of blood that is stored in the vessel.
- Compliance =distensility X______
8
quantity
volume
Four Sources of Resistance to Flow
- Blood vessel length—the longer the vessel, the greater the resistance.
- Blood vessel diameter —contributes the most in altering peripheral resistance (occurs in the arterioles). ________ “fourth power” law—if the radius of the blood vessel doubles the amount of flow does not double, it increases by a power of ___: 2 x 2 x 2x 2 = 16
- Series or _______ blood vessels—occurs in the capillaries. Although smaller in diameter, the vessels are smoother so less resistance. Also smaller in length so less resistance.
- Blood viscosity- normal viscosity of blood is 3 to 4 times the thickness of water. If other factors are equal (same length and diameter), the more viscous the blood the more ________ to flow.
Poiseuille’s
4
Parallel
resistance
flow = change in pressure over _________
if resistance goes up then flow goes down…
resistance
There are four primary forces (called starling forces) that determine if fluid will
move out of the blood into the interstitial space (filtration) or from the interstitial
space into the blood (absorption).
1.Capillary pressure (Pc)—tends to force fluid outward from the blood
2.Interstitial fluid pressure (Pif)—tends to force fluid into the blood when Pif is (+)
and outward if Pif is (-).
3.Plasma colloid osmotic pressure— tends to cause ______ of fluid into the
blood.
- Interstitial fluid colloid osmostic
pressure—tends to cause osmosis of fluid
outward from blood.
osmosis
