PGY 412 EXAM 2 QUESTIONS &
VERIFIED CORRECT ANSWERS
RATED 100% CORRECT
Pulmonary Circuit - CORRECT ANSWER Low Pressure Circuit
Volume dependent
Venous side
Defined by "Preload"- highly dependent upon venous return (VR)
CO from right side of the heart is the 'pulmonary' blood flow
Systemic Circuit - CORRECT ANSWER High Pressure
Pressure Dependent
Arterial side
Defined by "afterload"- highly dependent upon cardiac output (CO)
CO from left side of the heart is 'systemic' blood flow
Heart Histology: Pericardium - CORRECT ANSWER AKA 'Epicardium'
Outer, Fibrous sac with small amount of fluid within the pericardial space- helps muscle to
contract smoothly
3 layers with potential space
Heart Histology: Endocardium - CORRECT ANSWER Continuous with the 'endothelium' of
vessels and with the valves
Simple squamous epithelium
Connective tissue (BM)
,-Attaches to Myocardium
All valves open and closed based upon - CORRECT ANSWER Passive movement due to pressure
differences
Papillary muscles & Chordae Tendineae - CORRECT ANSWER Prevent prolapse of AV-valves
during systole
Pericardium layers - CORRECT ANSWER *Fibrous
*Serous (simple squamous)- parietal pericardium
-Space-
*Serous- visceral layer
Heart Histology: Myocardium - CORRECT ANSWER Cardiac muscle
-Central nuclei
-Syncytium arrangement
-Thickest layer
-Connective tissue
-Adipose
-Involuntary
-Gap Junctions
Blood Flow through Cardiovascular System - CORRECT ANSWER IVC/SVC > RA > Tricuspid Valve
> RV > Pulmonary Semilunar valve > Pulmonary Trunk > Pulmonary Artery > Lungs > Pulmonary
Veins > LA > Bicuspid Valve > LV > Aortic Semilunar Valve > Aorta > Arteries > Capillaries > Veins
> IVC/SVC
,The ability of the heart to eject blood during a heartbeat is a function of 3 factors - CORRECT
ANSWER * Amount of cardiac filling (preload)
* Strength of contraction (contractility)
*Pressure against which it ejects blood (afterload)
Systole - CORRECT ANSWER The period when the ventricle is contracting and ejection of blood
occurs
Diastole - CORRECT ANSWER The period when the ventricle is relaxing, and filling occursj
What factors improve the heart as a pump - CORRECT ANSWER *Increasing Preload
*Increasing Contractility
*Decreasing Afterload
What factors diminish heart as a pump - CORRECT ANSWER *Decrease preload
*Decrease contractility
*Increase afterload
Preload (Starling's Law) - CORRECT ANSWER *Up to a point, the heart pumps more when it is
filled more during diastole
*Increased ventricular 'filling' adds 'stretch' on the ventricular muscle, resulting in greater
contraction (up to a point of diminished returns)
*Called 'starlings law'
*At some point, excess stretch stops increasing output and eventually decreases it.
Define: Preload - CORRECT ANSWER Volume of blood in ventricles just before contraction-
volume dependent
*Can be expressed as: EDV, end-diastolic pressure, stretch on sarcomeres
, *Often synonymous with 'EDV' which is related to RA pressure and VR.
Preload is increased with: - CORRECT ANSWER *Increased VR
*Increased EDV
*Fluid retention
*Hypervolemia
*Heart Failure
*Regurgitation of cardiac valves
*Excessive venoconstriction (alpha-1)
*Increase stretch on the ventricular m.
**Anything that forces blood back to the heart, or increases VR or Venous Volume
Preload is decreased with: - CORRECT ANSWER *Low venous tone
*Hypovolemia
- Dizzy, vision trouble, weak, tachycardia, retain fluid- not making urine to be excreted
*Dehydration
An increase in EDV will _________ stroke volume - CORRECT ANSWER Increase
Contractility - CORRECT ANSWER the ability of the heart to contract at a given preload (EDV)
AKA 'Inotropism' or 'Inotropy'
*Intrinsic ability of cardiac muscle to generate force at a given EDV or muscle length
At a cellular level, 'contractility' is related to: - CORRECT ANSWER **Intracellular Ca++ levels
- Reflects amount of Ca++ released from SR
- Contractility strength is directly tied to Ca++ concentration in ICF
VERIFIED CORRECT ANSWERS
RATED 100% CORRECT
Pulmonary Circuit - CORRECT ANSWER Low Pressure Circuit
Volume dependent
Venous side
Defined by "Preload"- highly dependent upon venous return (VR)
CO from right side of the heart is the 'pulmonary' blood flow
Systemic Circuit - CORRECT ANSWER High Pressure
Pressure Dependent
Arterial side
Defined by "afterload"- highly dependent upon cardiac output (CO)
CO from left side of the heart is 'systemic' blood flow
Heart Histology: Pericardium - CORRECT ANSWER AKA 'Epicardium'
Outer, Fibrous sac with small amount of fluid within the pericardial space- helps muscle to
contract smoothly
3 layers with potential space
Heart Histology: Endocardium - CORRECT ANSWER Continuous with the 'endothelium' of
vessels and with the valves
Simple squamous epithelium
Connective tissue (BM)
,-Attaches to Myocardium
All valves open and closed based upon - CORRECT ANSWER Passive movement due to pressure
differences
Papillary muscles & Chordae Tendineae - CORRECT ANSWER Prevent prolapse of AV-valves
during systole
Pericardium layers - CORRECT ANSWER *Fibrous
*Serous (simple squamous)- parietal pericardium
-Space-
*Serous- visceral layer
Heart Histology: Myocardium - CORRECT ANSWER Cardiac muscle
-Central nuclei
-Syncytium arrangement
-Thickest layer
-Connective tissue
-Adipose
-Involuntary
-Gap Junctions
Blood Flow through Cardiovascular System - CORRECT ANSWER IVC/SVC > RA > Tricuspid Valve
> RV > Pulmonary Semilunar valve > Pulmonary Trunk > Pulmonary Artery > Lungs > Pulmonary
Veins > LA > Bicuspid Valve > LV > Aortic Semilunar Valve > Aorta > Arteries > Capillaries > Veins
> IVC/SVC
,The ability of the heart to eject blood during a heartbeat is a function of 3 factors - CORRECT
ANSWER * Amount of cardiac filling (preload)
* Strength of contraction (contractility)
*Pressure against which it ejects blood (afterload)
Systole - CORRECT ANSWER The period when the ventricle is contracting and ejection of blood
occurs
Diastole - CORRECT ANSWER The period when the ventricle is relaxing, and filling occursj
What factors improve the heart as a pump - CORRECT ANSWER *Increasing Preload
*Increasing Contractility
*Decreasing Afterload
What factors diminish heart as a pump - CORRECT ANSWER *Decrease preload
*Decrease contractility
*Increase afterload
Preload (Starling's Law) - CORRECT ANSWER *Up to a point, the heart pumps more when it is
filled more during diastole
*Increased ventricular 'filling' adds 'stretch' on the ventricular muscle, resulting in greater
contraction (up to a point of diminished returns)
*Called 'starlings law'
*At some point, excess stretch stops increasing output and eventually decreases it.
Define: Preload - CORRECT ANSWER Volume of blood in ventricles just before contraction-
volume dependent
*Can be expressed as: EDV, end-diastolic pressure, stretch on sarcomeres
, *Often synonymous with 'EDV' which is related to RA pressure and VR.
Preload is increased with: - CORRECT ANSWER *Increased VR
*Increased EDV
*Fluid retention
*Hypervolemia
*Heart Failure
*Regurgitation of cardiac valves
*Excessive venoconstriction (alpha-1)
*Increase stretch on the ventricular m.
**Anything that forces blood back to the heart, or increases VR or Venous Volume
Preload is decreased with: - CORRECT ANSWER *Low venous tone
*Hypovolemia
- Dizzy, vision trouble, weak, tachycardia, retain fluid- not making urine to be excreted
*Dehydration
An increase in EDV will _________ stroke volume - CORRECT ANSWER Increase
Contractility - CORRECT ANSWER the ability of the heart to contract at a given preload (EDV)
AKA 'Inotropism' or 'Inotropy'
*Intrinsic ability of cardiac muscle to generate force at a given EDV or muscle length
At a cellular level, 'contractility' is related to: - CORRECT ANSWER **Intracellular Ca++ levels
- Reflects amount of Ca++ released from SR
- Contractility strength is directly tied to Ca++ concentration in ICF
