Flashcards in Quiz 3 Deck (51)
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1
Flow is governed by...
Pressure and resistance
2
Pressure
Moves fluid
3
Resistance
Opposes movement
4
By pulling back a syringe...
We increase the volume and decrease the pressure
The pressure outside the syringe is greater than the inside, so air moves in
5
By pushing on a syringe...
We decrease the volume and increase the pressure
The pressure outside the syringe is less than the inside, so air moves out
6
Heart Sounds
S1 and S2
7
S1
Closure of the AV valves
"Lub"
8
S2
Closure of the semilunar valves
"Dub"
9
Valvular Regurgitation
A condition in which blood leaks in the wrong direction because one or more heart valves closes improperly
Mitral valve prolapse is a common cause
10
Events of Ventricular Systole
Ventricular contraction
Atrial relaxation (filling)
11
Events of Ventricular Diastole
Ventricular relaxation (filling)
Atrial diastole continues throughout most of diastole
Atrial systole (ejection into ventricles) occurs near the end of diastole
12
End Diastolic Volume
Volume in each ventricle at the end of diastole (120-130mL)
13
End Systolic Volume
Volume remaining after systole (50-60mL)
14
Stroke Volume
Volume ejected per beat (EDV-ESV)
15
Ejection Fraction
Blood at beginning of systole ejected during systole
(EF=SV/EDV)
Lower EF indicated you are not pumping as much blood per beat, so therefore not as much blood to tissues
16
Ventricular Diastole (Passive Filling)
30mL
17
Atrial Systole
40mL
18
Stroke Volume
-70mL
19
EF
0.53mL
20
Necessity of Balanced Ventricular Output
1. Right ventricular output exceeds left ventricular output
2. Pressure backs up
3. Fluid accumulates in pulmonary tissues
1. Left ventricular output exceeds right ventricular output
2. Pressure backs up
3. Fluid accumulates in systemic tissue
21
Nerve Supply to the Heart
Autonomous: Intrinsic Rate
Receives additional input from the CNS
Sympathetic and parasympathetic input
22
Autonomic Regulation
Sympathetic stimulation to the heart originates in the lower cervical to upper thoracic spinal cord
Speeds up the heart and increases blood flow and ventricular output
23
Parasympathetic Stimulation
Originates in the nuclei of the vagus nerve in the medulla oblongata
Vagus nerve innervates SA and AV nodes
Slows the heart
24
Cardiac Output
Amount of blood pumped per beat per minute
Affected by stroke volume and heart rate (HR increases CO the most)
25
Cardiac Reserve
Difference between maximum output and output at rest
26
Three Factors that Affect Stroke Volume
Preload
Contractility
Afterload
27
Preload
Starling's Law of the Heart
Amount of tension on ventricular myocardium before it contracts
Increased Preload=Increased Contraction Strength
28
Starling's Law of the Heart
Ventricles eject as much blood as they receive
The more they are stretched, the harder they contract
29
Contractility
Contraction force for a given preload
Increased interaction affects stroke volume
30
