CARDIOVASCULAR SYSYTEM Flashcards
Hollow, muscular organ located in the center of the thorax
HEART
The heart weighs approximately
300g
__________of fluid in the pericardial sac
10-20 ml
HEART FUNCTION:
Pump oxygenated blood to cells and tissues
Function of pericardial fluid:
prevent friction between visceral and parietal
EPICARDIUM
Outermost layer
inflammation of pericardium
PERICARDITIS:
Angina
= relieved by rest
Myocardial Infarction drug?
morphine sulfate
Contains 2 layers
Visceral
Parietal
The cardiac muscle or middle layer which is made up of muscle fibers
MYOCARDIUM
Inner layer which consists of endothelial tissue and lines the inside of the heart and valves
ENDOCARDIUM
RIGHT ATRIUM location:
4th intercostal space, right midclavicular line
Receives venous blood from the right atrium, and ejects this blood into the lungs via the pulmonary artery
RIGHT VENTRICLE
Receives venous blood returning to the heart via the superior and inferior vena cava
RIGHT ATRIUM
Receives oxygenated blood from the lungs and then empties the blood into the left ventricle
LEFT ATRIUM
Receives oxygenated blood from the left atrium of and ejects blood into the systemic arterial circulation via the aorta
LEFT VENTRICLE
LEFT VENTRICLE location:
5th intercostal space, left midclavicular line
Responsible for apex beat or point of maximal pulse
LEFT VENTRICLE : 5 ICS, LMCL
During __________ of the muscle or ___________ , the chambers of the heart becomes __________ as the blood is ejected
contraction; systole - smaller
During _____________ of the muscles of the heart wall or ___________, the heart chambers _______ with blood in preparation for the subsequent ejection
relaxation; diastole - fill
amount of blood that is ejected from either ventricle per minute
5L
ATRIOVENTRICULAR VALVE
These valves open during ventricular systole, and they close during ventricular diastole
SEMILUNAR VALVE
Lies between the right ventricle and pulmonary artery
Pulmonary valve
Lies between the left ventricle and the aorta
Aortic valve
Vessels that supply blood to the heart muscle; They originate from the aorta
CORONARY ARTERY
LEFT CORONARY ARTERY; TWO BRANCHES
Circumflex coronary artery
LADA (Left Anterior Descending Artery)
Supplies: left atrium, lateral surface of left ventricle
Circumflex coronary artery
Anterior wall of left ventricle, apex of heart
LADA (Left Anterior Descending Artery)
TWO CORONARY ARTERY
LEFT CORONARY ARTERY
RIGHT CORONARY ARTERY
It is the beginning of the conduction system and normally function as the pacemaker of the heart
SINOATRIAL NODE
Supplies the right atrium, right ventricle, a portion of the septum, SA node, AV node and inferior portion of the left ventricle
RIGHT CORONARY ARTERY
SINOATRIAL NODE LOCATION?
Located at the junction of the superior vena cava and the right atrium
Generates and transmits electrical impulses that stimulate contraction of the myocardium
CONDUCTION SYSTEM
A bundle of specialized muscle fibers – that travel in the septum separating the left and right ventricles
BUNDLE OF HIS
Right bundle branch
Right ventricles
Left bundle branch
left ventricles
BUNDLE OF HIS
Ventricular depolarization
Point at which the myocardial cells are stimulated, causing ventricular contraction
PURKINJE FIBERS
Composed of specialized cells to rapidly conduct the impulses through the thick walls of the ventricles
PURKINJE FIBERS
Atrial depolarization
P Interval/Wave
Complete ventricular depolarization
PURKINJE FIBERS
0.04 – 0.11 secs
P Interval/Wave
0.12 – 0.20 secs
PR Interval
Impulse transmission from SA – AV node
PR Interval
Ventricular depolarization
QRS
0.05 – 0.10 secs
QRS
Plateau phase
ST Segment
Gap between ventricular depolarization and ventricular repolarization
ST Segment
Complete ventricular repolarization
U Wave
MI and hyperkalemia = elevated
ST Segment
Ventricular repolarization
T Wave
Initial sign of hyperkalemia
o Weakness
o Bounding pulse
o Cardiac and respiratory arrest
o Everything is high and fast
Hyperkalemia DOC
Calcium gluconate, insulin, glucos, calcium bicarbonate, kayexalate, dialysis
Hypokalemia DOC
Potassium chloride
Coordinates the incoming impulses from the SA node
ATRIOVENTRICULAR NODE
SYSTOLE
Contraction and emptying of the atria and ventricles
Hypocalcemia
Muscle twitching, tremors, paresthesia, Chvostek’s sign, Trousseau’s sign
DIASTOLE
Relaxation and filling of the atria and the ventricles
The volume of blood ejected from the left ventricle into the aorta per minute
CARDIAC OUTPUT
Average Cardiac Output
5L/min
equation of CO
CO = SV x HR
Delay transmission of impulse going to ventricles____________________
to allow for complete atrial depolarization
Amount of blood ejected by the left ventricle into the aorta per beat
STROKE VOLUME
Delay transmission of impulse going to ventricles to allow for complete atrial depolarization
ATRIOVENTRICULAR NODE
STROKE VOLUME
Determined by three factors:
preload, contractility, and afterload
Degree of myocardial fiber stretch before contraction
PRELOAD
The greater myocardial fiber stretches, within physiologic limits, the more forceful the ventricular contraction, thereby increasing stroke volume
FRANK-STERLING LAW
STROKE VOLUME per ML
70mL
PRELOAD
It is related to the volume of blood distending the ventricles at the end of diastole
Do not give digoxin if pulse rate <60
to prevent rebound bradycardia
Digoxin
increase cardiac contractility and decrease HR
Ability of the heart muscle to contract and thereby pump blood
CONTRACTILITY
Before taking Digoxin
Check pulse (apical)
SIDE EFFECT DIGOXIN/DIGITALIS
Blurring of vision
Anorexia
Nausea and vomiting
Dysrhythmia
Green halos around eyes
Do not give digoxin if pulse rate >120
rebound tachycardia
when taking digoxin, what electrolyte to check?
Check potassium (hypokalemia)
Amount of pressure that the heart needs to exert to eject the blood during ventricular contraction
AFTERLOAD
How to assess a pt. with JVD?
supine position & (HOB) at 30-45° angle.
If it remains engorged, then there is jugular vein distention
Due to fluid volume excess
NECK VEIN DISTENTION (JUGULAR VEIN DISTENTION)
Jugular Vein Distention (JVD) may indicate:
Right sided congestive heart failure
Produced by asynchronous closure of the mitral and tricuspid valves
S1 (LUB)
Produced by asynchronous closure of the aortic and pulmonic valves
S2 (DUB)
It signals the onset of ventricular systole
S1 (LUB)
It signals the onset of ventricular diastole
S2 (DUBB)
o A faint, low pitched sound produced by rapid ventricular filling in early diastole
S3
It is a low frequency sound which is present in congestive heart failure
S4
o It is normal in children and in young adults
o It indicates congestive heart failure in older adults
S3 sound
Abnormal in all ages
S4 sound
Rule in JVD
Angle of Loui’s (add 5)
Normal CVP
5-12 cm of water
The first and second heart sounds are best heard with the _____________ of the stethoscope
diaphragm = high pitched
Extra heart sounds are best heard with the ____ of the stethoscope
bell = low pitched
Use the _____________ of the stethoscope when auscultating the ______-area
diaphragm= apical
During auscultation of extra heart sounds, place the client in _______________ position
upright leaning forward
CENTRAL VENOUS PRESSURE
Monitors the pressure within the right atrium
CVP: 3 sites of catheter insertion
Subclavian
Internal jugular
Femoral
CVP: Normal reading
Superior vena cava = 5-12 cm H2O
Right atrium = 0-10 cm H2O
↑CVP = FVE
↓CVP = FVD
FVD
CVP: The O level of the water manometer should be placed at the____________
4th ICS, RMCL
