Ace Physio Chapter 14 (Part 1): Comprehensive Review and
Preparation
Fun Fact!
Average Heart Rate = 70 BPM
Average Stroke Volume = 70-80 mL/beat
Average Cardiac Output = 5500 mL/min - correct answer ✔✔Fun Fact!
_____ occurs at SA node when HCN channels open, allowing Na+ in - correct answer ✔✔spontaneous
depolarization
Sympathetic norepinephrine and adrenal epinephrine keep ____ open, increasing heart rate - correct
answer ✔✔HCN channels
_____ opens K+ channels, slowing heart rate - correct answer ✔✔parasympathetic acetylcholine
Cardiac rate is controlled by the cardiac center of... - correct answer ✔✔medulla oblongata
Regulation of Stroke Volume
Answer (A)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
,- Stroke volume increases with contractility - correct answer ✔✔End diastolic volume
Regulation of Stroke Volume
Answer (B)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
- Stroke volume increases with contractility - correct answer ✔✔Total peripheral resistance
Regulation of Stroke Volume
Answer (C)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
- Stroke volume increases with this - correct answer ✔✔Contractility
, Increased EDV results in increased contractility and thus increased stroke volume - correct answer
✔✔Frank-Starling Law
Intrinsic Control of Contraction Strength
Answer (A)
Due to (A)
- Increased EDV stretches the (B), which increases contraction strength.
- Due to increased myosin and actin overlap and increased sensitivity to Ca2+ in cardiac muscle cells -
correct answer ✔✔myocardial stretch
Intrinsic Control of Contraction Strength
Answer (B)
Due to (A)
- Increased EDV stretches the (B), which increases contraction strength.
- Due to increased myosin and actin overlap and increased sensitivity to Ca2+ in cardiac muscle cells -
correct answer ✔✔myocardium
Sympathetic norepinephrine and adrenal epinephrine can increase contractility by making more Ca2+
available to ____ - correct answer ✔✔sarcomeres
End diastolic volume is controlled by what factors that affect venous return - correct answer ✔✔total
blood volume, venous pressure
Veins are ___, stretch at a given pressure. They hold more blood than arteries but maintain lower
pressure - correct answer ✔✔compliant
____ control the movement of water between the interstitial spaces and the capillaries, affecting blood
volume - correct answer ✔✔Osmotic forces
Preparation
Fun Fact!
Average Heart Rate = 70 BPM
Average Stroke Volume = 70-80 mL/beat
Average Cardiac Output = 5500 mL/min - correct answer ✔✔Fun Fact!
_____ occurs at SA node when HCN channels open, allowing Na+ in - correct answer ✔✔spontaneous
depolarization
Sympathetic norepinephrine and adrenal epinephrine keep ____ open, increasing heart rate - correct
answer ✔✔HCN channels
_____ opens K+ channels, slowing heart rate - correct answer ✔✔parasympathetic acetylcholine
Cardiac rate is controlled by the cardiac center of... - correct answer ✔✔medulla oblongata
Regulation of Stroke Volume
Answer (A)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
,- Stroke volume increases with contractility - correct answer ✔✔End diastolic volume
Regulation of Stroke Volume
Answer (B)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
- Stroke volume increases with contractility - correct answer ✔✔Total peripheral resistance
Regulation of Stroke Volume
Answer (C)
1. (A): volume of blood in the ventricles at the end of diastole
- Sometimes called preload
- Stroke volume increases with increased EDV
2. (B): Frictional resistance in the arteries
- Inversely related to stroke volume
3. (C): strength of ventricular contraction
- Stroke volume increases with this - correct answer ✔✔Contractility
, Increased EDV results in increased contractility and thus increased stroke volume - correct answer
✔✔Frank-Starling Law
Intrinsic Control of Contraction Strength
Answer (A)
Due to (A)
- Increased EDV stretches the (B), which increases contraction strength.
- Due to increased myosin and actin overlap and increased sensitivity to Ca2+ in cardiac muscle cells -
correct answer ✔✔myocardial stretch
Intrinsic Control of Contraction Strength
Answer (B)
Due to (A)
- Increased EDV stretches the (B), which increases contraction strength.
- Due to increased myosin and actin overlap and increased sensitivity to Ca2+ in cardiac muscle cells -
correct answer ✔✔myocardium
Sympathetic norepinephrine and adrenal epinephrine can increase contractility by making more Ca2+
available to ____ - correct answer ✔✔sarcomeres
End diastolic volume is controlled by what factors that affect venous return - correct answer ✔✔total
blood volume, venous pressure
Veins are ___, stretch at a given pressure. They hold more blood than arteries but maintain lower
pressure - correct answer ✔✔compliant
____ control the movement of water between the interstitial spaces and the capillaries, affecting blood
volume - correct answer ✔✔Osmotic forces
