Cardiovascular System Flashcards
Precordium
Area on anterior chest overlying the heart and great vessels
Great vessels
Major arteries and veins connected to the heart
The heart and great vessels are located between the
Lungs in the middle third of the thoracic cage
Mediastinum
Where the heart and great vessels are located
-between the lungs in the middle third of the thoracic cage
The heart extends from the levels of the ___ to ____ intercostal spaces
Second and fifth
During contraction, which part of the heart is creating the apical impulse by beating against the chest wall
The apex (bottom of the heart)
Where is the apical pulse palpable
The fifth intercostal
-7 to 9cm from Midsternal line
The great vessel lies
Bunched above the base of the heart
The superior and inferior venae cavae return ____ ___ blood to the ___ side of the heart
Return DE-OXYGENATED VENOUS
To the RIGHT side
Pulmonary artery leaves the __ ventricle
Right
-carries venous blood to lungs
Pulmonary veins return what type of blood?
Freshly oxygenated blood to left side of the heart
What carries oxygenated blood out to the body?
Aorta
Pericardium
Tough, fibrous, double walled sac surrounding/protecting the heart
What is found in between the two layers of the pericardium?
Pericardial fluid
-aids in reducing friction allowing for smooth movement of heart muscle
Myocardium
Muscular wall of the heart
-does the pumping
Endocardium
Thin layer of endothelial tissue lining the inner surface of heart chamber and values
Atrium vs ventricle
Atrium- thin walled reservoir for holding blood
Ventricle- thick walled muscular pumping chamber
How many chambers are there in the heart
Fourt
How are the chambers separated
By swinging door like structures called valves
Function of valves
Prevent back flow of blood
What does it mean by the valves are unidirectional
They can open only one way
-open and close passively in response to pressure gradients in the moving blood
What valves separate the atria and ventricles
Atrioventricular valves
The right AV valve
Tricuspid valve
Left Av valve
Bicuspid or mitral valve
Two different types of atrioventriclar valves
Tricuspid (right) and mitral (left)
The valves thing leaflets are anchored by collagenous fibres to papillary muscles embedded in the ventricle floor called
Chordae tendineae
When do the AV valves open
During hearts filling stage or diastole
Why do AV valves open
During diastole so that ventricles can fill with blood
When do the AV valves close
During the pumping phase or systole
Why do AV valves close
To prevent regurgitation of blood back up into atria
When do the papillary muscles contract
During systole
-so that the valve leaflets meet and untie to form a perfect seal without turning themselves inside out
Where are the semilunar valves
Between ventricles and pulmonary arteries
Each semi lunar valve has
Three cusps that look like half moons
What are the two semilunar valves
Pulmonic valve (right side) and aortic valve (left side)
Semilunar valves open during
Pumping (systole) to allow blood to be ejected from the heart
Where are there no valves
Between the venae cavae and right atrium, or between pulmonary veins and left atrium
Because there are no valves between venae cavae and right atrium, and the pulmonary veins and left atrium what can happen on the left side of the heart
Abnormal high blood pressure in the left side of the heart produce symptoms of pulmonary congestion, heart failure
Because there are no valves between venae cavae and right atrium, and the pulmonary veins and left atrium what can happen on the right side of the heart
Abnormally high pressure in the right side of the heart manifests as distension of neck veins and abdomen
Blood flows from liver to
Right atrium via inferior vena cava
Superior vena cava drains venous blood from
Head and upper extremities
From right atrium venous blood travels through tricuspid valve to
Right ventricle
From right ventricle, enough blood flows through
Pulmonary valve to pulmonary artery
Pulmonary artery delivers
unoxygenated blood to lungs
Lungs oxygenate the blood then travels to
Pulmonary veins where it returns fresh blood to left atrium
From left atrium arterial blood travels through
Mitral valve to left ventricle
Left ventricle ejects blood through
Aortic valve into aorta
What are the two phases of the cardiac cycle
Diastole and systole
Diastole vs systole
Diastole- ventricles relax and fill with blood
Systole- hearts contraction and blood is pumped from ventricles (into pulmonary and aortic arteries)
In diastole the ___ valves are open
AV
During diastole the pressure in the ___ is higher than in the __
Atria, ventricles
-so that blood pours rapidly into the ventricles
Early or protodiastolic filling
First passive filling phase
Presyostole or atrial systole
Toward end of diastole, atria contract and push last amount of blood into ventricles
-atrial kick
Presystole or atrial systole causes a
Small rise in left ventricular pressure
As ventricular pressure rises due to the increased volume at the end of diastole, what happens
The mitral and tricuspid valves swing shut
First heart sound (S1) is caused by
Closing of the AV valves
What is the signal of systole
S1
For a very brief time after S1 what is happening
All four valves are closed
What happens due to the brief period of time where all the valves are closed
Ventricular walls contract within the closed system increasing the pressure to a higher level —> ISOMETRIC CONTRACTION
When the pressure in the ventricle finally exceeds pressure in the aorta (isometric contraction) what happens
The aortic valve opens and blood is ejected rapidly
What happens once all the ventricles are ejected
Pressure falls, and when pressure is below aorta pressure some blood flows backward toward ventricle causing aortic valve to shut
What is the cause of the second heart sound (S2)
Closure of semilunar valves
-end of systole
Isometric or isovolumic relaxation
After end of systole, all four valves are closed and ventricles relax
-but atria have been filing with blood from lungs and so pressure in atrias are higher than ventricles again, so mitral valve drifts open and diastolic filling begins again
During inspiration ___ pressure is decreased, this pushes more
Intrathoracic pressure
-pushes more blood into venae cavae increasing venous return to right side of the ehart
moRe to the
Right
Less to the
Left
Normally ___ is a silent event
Diastole
S3
In some conditions ventricular filling creates vibration that can be heart over the chest
-ventricles are resistant to filling during protodiastole
Where is S2 loudest
At the base
S4
End of diastole at presystole, when ventricle is resistant to filling
-atria contracts and pushes blood into a non compliant ventricle, creating vibrations
S4
End of diastole at presystole, when ventricle is resistant to filling
-atria contracts and pushes blood into a non compliant ventricle, creating vibrations
What three conditions cause murmurs
- Increase in velocity of blood flow
- Decrease in viscosity of blood
- Structural defects in valves or unusual opening in the chambers
Murmur
Gentle, blowing, swooshing sound
Increases in velocity of blood flow example
Flow murmur, exercise, thyrotoxicosis
Example of decreases in viscosity of blood
Anemia
Four characteristics of sound
- Frequency
- Intensity
- Duration
- Timing
Sinoatrial node
Intrinsic rhythm know as the pacemaker
Sequence of conduction
SA node across atria to AV to bundle of his to fascicles branches then ventricles
P wave
Depolarization of the atria
P wave
Depolarization of the atria
P-R interval
Time necessary for atrial depolarixaiton plus time for the impulse to travel through the AV node to the ventricles
QRS complex
Depolarization of the ventricles
T wave
Repolarixaiton of ventricles
Order of an ECG wave
P wave, P-R interval, QRS complex, T wave
Electrical events slightly ___ the mechanical events in the heart
Precede
How much blood does a resting adult pump per minute throughout the body
4 and 6 L
Preload
Venous return that builds during diastole
-length to which ventricular muscle is stretched at the end of diastole before contraction
Frank startling law
The greater the stretch the stronger the hearts contraction
After load
Opposing pressure that the ventricle must generate to open the aortic valve against the higher aortic pressure
Where is the carotid artery located
In the groove between the trachea and sternomastoid msucle
Function of the jugular vein
Empties unoxygenated blood directly into the superior vena cava
What do the jugular veins tell us
About activity on the right side of the heart
What are the two jugular veins
Internal jugular vein and external jugular vein
Internal jugular vein
Deep and medial to sternomastoid muscle
-not usually visible
When can you see pulse from internal jugular vein
Supine position, seen in sternal notch
External jugular vein
Superficial- lies lateral to sternomastoid muscle above clavicle
Fetal considerations
-fetal heart function at 3 weeks gestation
-oxygenation at placenta
-blood doesn’t pump through pulmonary system instead via foremen ovale into left side of heart
-ductus arteriosus moves from pulmonary artery to aorta
When does the foremen ovale close
Within first hour of after birth due to new pressure
When does the ductus arteriosus close
10 to 15 hours after birth
Heart position in the chest as an infant
More horizontal than in adults
Heart considerations in pregnant women
-blood volume inc 30/40%
-inc SV, CO, pulse
-decrease in BP
Why does blood pressure decrease in pregnancy
Peripheral vasodilation
Blood pressure and aging- why?
Systolic blood pressure increases
-thickening and stiffening of large arteries
-increases pulse wave velocity and arteries cannot store volume ejected
Left ventricular wall in OA
Thickness increases
-adaptive to accommodate vascular stiffening which makes an increase in workload
Variations in S1
-loud/accentuated
-faint/diminished
-varying intensity
-split
Examples of loud S1
Hyperkinetic states in which blood velocity is increased: exercise, fever, anemia, hyperthyroidism
Mitral stenosis
Examples of faint S1
First degree heart block
Mitral insufficieny
Severe hypertension
Varying intensity of S1 examples
Arteries fibrillation
Complete heart block with changing PT interval
Split S1 example
Normal but uncommon
Variations in S2
-accentuated
-dismissed
Example of accentuated S2
Systemic hypertension
Exercise and excitement
Mitral stenosis, heart failure
Aortic or pulmonic stenosis
Examples of dismissed S2
Shock
Aortic or pulmonic stenosis
