Cardiovascular System Flashcards
The cardiovascular system consists of?
The heart(pump) High pressure distribution circuit Exchange vessels Low pressure collection and return circuit
The high pressure distribution circuit is also known as?
Arteries
The aorta and its major branches serve a ______ function, while the muscular arteries serve a _____ function
Transport
Distributive
The exchange vessels are also known as the?
Capillaries
The capillaries are ____ in diameter
8-10 micrometers
Capillaries can possess three types of endothelium namely?
Continuous endothelium
Fenestrated endothelium
Discontinuous endothelium
Capillaries containing continuous endothelium are found in the?
Muscle
Heart
Liver
Brain
Capillaries containing fenestrated endothelium are found in the?
Gastrointestinal tract
Renal glomeruli
Capillaries containing discontinuous endothelium are found in the?
Liver
Spleen
The low pressure collection and return circuit is also known as?
The veins
The four actions of the heart are?
Chronotropic action
Inotropic action
Dromotropic action
Bathmotropic action
The heart action that deals with the frequency of heartbeat or heart rate is?
Chronotropic action
Chronotropic action is divided into two, namely?
Tachycardia
Bradycardia
Tachycardia is the ___ in heart rate
Increase
Bradycardia is the ___ in heart rate
Decrease
The heart action that deals with the heart’s force of contraction is?
Inotropic action
Inotropic action is divided into two, namely?
Positive(increase)
Negative (decrease)
The heart action that deals with the conduction of impulse(velocity) through the heart is?
Dromotropic action
Dromotropic action is divided into two, namely?
Positive(increase)
Negative(decrease)
The heart action that deals with the excitability of cardiac muscle is?
Bathmotropic action
Bathmotropic action is divided into two, namely?
Positive(increase)
Negative (decrease)
The ___ and ___ regulate all the actions of the heart
Stimulation of nerves supplying the heart
Hormones or hormonal substances
The cardiovascular system is a ____ system
Closed
Cardio means?
Heart
Vascular means?
Vessels
The functions of the cardiovascular system are to?
Transport oxygen and nutrients to the cells of the body
Remove metabolic waste products and carbon dioxide from the body
The components of the CVS are?
Heart
Blood vessels
The heart is a pump made up of ___ chambers, namely
4
2 atria and 2 ventricles
The blood vessels are divided into?
Arteries and arterioles
Veins and venules
Blood capillaries
The function of the Arteries and arterioles is to?
Carry blood from the heart to all parts of the body
The function of the veins and venules is to?
Carry blood from all parts of the body back to the heart
The ___ serve as distribution channels to the organs, while the ___ serve as blood reservoirs and collect blood to return it to the heart
Arteries
Veins
The function of blood capillaries is to?
Serve as sites of exchange of gases(O2 & CO2), nutrients and waste products between blood and tissues
Blood capillaries form a network of fine vessels connecting the ___ to the ___
Arterioles
Venules
The cardiovascular system is made up of two circulatory systems, namely?
Pulmonary circulation
Systemic circulation
The function of pulmonary circulation is to?
Oxygenate the blood
In pulmonary circulation, deoxygenated blood leaves the ___ through the ___ and then returns oxygenated blood through the ___ to the ___
Right ventricle
Pulmonary arteries
Pulmonary veins
Left atrium
In systemic circulation, oxygenated blood leaves the ___ through the ___ and returns deoxygenated blood to the heart through the ____ and ends in the ___
Left ventricle
Aorta
Superior and inferior Vena Cava
Right atrium
The pathway of pulmonary circulation is?
Right ventricle Pulmonary trunk Pulmonary arteries Pulmonary capillaries Pulmonary veins Left atrium
The pathway of systemic circulation is?
Left ventricle Aorta Systemic arteries(Arterioles) Systemic capillaries Systemic veins(Venules) Superior and inferior Vena Cava Right atrium
The two circulations are in series, meaning?
Blood finishes one circulation to start the other
Blood carries out it’s respiratory function more efficiently by going ____ through the systemic capillaries and ____ through the pulmonary capillaries
Once
Both ventricles must pump ___ volume of blood because of the ___ arrangement of the systemic and pulmonary circulations
Equal
Series
In the heart, the high pressure side of the heart is?
The left side of the heart(systemic circulation)
In the heart, the low pressure side of the heart is?
The right side of the heart(pulmonary circulation)
The arteries have properties of___&___
Stretch(distension or compliance)
Recoil
During ventricular contraction (systole), arteries ___ by the blood ejected into them
Distend
During ventricular contraction, energy is at ___ in the walls of the arteries
Load
During ventricular relaxation (diastole), the energy released, causes ___ of the walls of the arteries
Elastic recoil
Elastic recoil of the walls of the arteries acts as an additional _____
Pump
Efficient pressure maintained during systole and diastole, results into ____ through the tissues
Continuous blood flow
Arterioles are resistance vessels that act as?
Variable resistors
Arterioles act as variable resistors because?
Their diameters continuously undergo changes in order to regulate the amount of blood flow into capillaries
Arterioles are considered as___ regulating blood flow to the tissues
Taps
The veins act as?
Capacitance vessels
Veins act as capacitance vessels because?
They hold most of the blood volume (volume reservoir)
Veins have a ____ capacity and ____
High distending
High compliance
Veins can ____ blood depending upon the underlying condition
Store or mobilize
The general function of the CVS is to?
Maintain homeostasis by continuous adequate blood flow to tissues
The heart is covered by a fibrous sac called the?
Pericardium
The heart lies in the left side of the?
Thoracic cavity
The heart lies behind the?
Sternum
The heart lies between the?
Right and left lungs
The heart is a ____ organ
Hollow muscular
The walls of the heart are composed of a muscle called the?
Cardiac muscle or myocardium
The ventricles occupy the ___ of the heart
Bulk
The arteries and veins all attach to the?
Base of the heart
One way flow is ensured by two sets of?
Valves
The human heart has ___ chambers
4
The 2 atria are separated from each other by?
Interatrial septum
The 2 ventricles are separated from each other by?
Interventricular septum
The wall of the left ventricle is about ____ times thicker than the wall of the right ventricle
3
The ____ is much thicker and stronger than the ___
Ventricular myocardium
Atrial myocardium
The atrial muscle of both atria is completely separated from the ventricular muscle of both ventricles by a fibrous ring called the?
Atrioventricular ring(AV ring)
The two functions of the atria are?
They act as blood reservoirs for the blood returning back to the heart
They act as primer pumps
The function of the ventricles is to?
Pump blood into the arteries
The right ventricle is called the?
Pulmonary pump
The left ventricle is called the?
Systemic pump
Atrial contraction pushes about ___ of the blood filling the ventricles during ventricular diastole
25%
During ventricular diastole, ___ of the blood that fills the ventricles pass passively i.e by their own weight
75%
The human heart contains ___ valves
4
The valves of the human heart are divided into two namely?
Two atrioventricular valves (AV valves)
Two semilunar valves
The atrioventricular valves are the?
Tricuspid valve
Bicuspid (mitral) valve
The tricuspid valve is found between the?
Right atrium and the right ventricle
The bicuspid(mitral) valve is found between the?
Left atrium and left ventricle
The semilunar valves are the?
Aortic valve
Pulmonary valve
The aortic valve is found between the?
Left ventricle and the aorta
The pulmonary valve is found between the?
Right ventricle and pulmonary trunk
The cardiac valves allow for blood to pass only in ___direction
One
The ___ allow blood to pass from the atria into the ventricles during ventricular diastole
AV valves
The ___ close to prevent back flow of blood from the ventricles into the atria during ventricular systole
AV valves
The ___ allow blood to pass from the ventricles into the arteries during ventricular systole
Semilunar valves
The ___ close to prevent back flow of blood from the arteries to the ventricles during ventricular diastole
Semilunar valves
The cardiac valves open or close depending upon the ____ of the blood on both sides of the valves
Pressure gradient
The ___ open when the atrial pressure becomes higher than the ventricular pressure
AV valves
The ___ close when the ventricular pressure becomes higher than the atrial pressure
AV valves
The ___ opens when the ventricular pressure becomes higher than the arterial pressure
Semilunar valves
The ____ closes when the arterial pressure becomes higher than the ventricular pressure
Semilunar valves
The right ventricle is also known as?
Flow generator
The normal cross section of the right ventricle is _____ shaped
Crescent
Right ventricular hypertrophy is the?
Thickening of the right ventricular free wall
Right ventricular hypertrophy is caused by?
Right ventricle ejecting blood against high pressure for prolonged periods of time( seen in pulmonary disease)
Right ventricle pumps large volumes of blood at ______ through the pulmonary circulation
Low pressure
The left ventricle pumps large volumes of blood at _____ through the systemic circulation
High pressure
The left ventricle is ____ in shape
Cylindrical
The left ventricle has a ___ wall than the right ventricle
Thicker
The left ventricle is also known as the?
Pressure generator
The systemic circulation has more____ than the pulmonary circulation
Pressure
The left ventricle is more commonly affected by ____ than the right ventricle
Disease
During ventricular____, blood is pumped into the circulation
Systole
During ventricular_____, the pumping of blood stops and the ventricles get filled with blood
Diastole
Due to systole and diastole, the flow of blood into the systemic and pulmonary circulations is an?
Intermittent pulsatile flow
Intermittent pulsatile flow means?
Rhythmic propagation of a fluid through a blood vessel at regular intervals
Heart rate is under ____ control
Neural
_____ efferent activity increases heart rate, while _____ efferent activity decreases heart rate
Cardiac sympathetic Cardiac parasympathetic (vagal)
The heart of a normal adult male beats automatically and regularly at a rate of ____ during rest
75 beats/minute
The normal range of heart rate is between?
60-100 beats/min
The stroke volume for each ventricle averages ___ of blood and a normal heart rate is approximately____
70 ml
70-75 beats/minute
The cardiac output at rest is approximately?
5L/min
The length and diameter of the superior Vena Cava are ____&____ respectively
2cm to 3cm
Approx. 7cm
The length and diameter of the inferior Vena Cava are ____&____ respectively
22cm
0.46-3cm
The connective tissue of arteries is thicker and more than the?
Vein
The resistance of the arteries to blood flow is called?
Peripheral resistance
Peripheral resistance is an important factor in generating and maintaining?
Arterial blood pressure
_____ of small vessels increases peripheral resistance, which elevates the arterial blood pressure
Vasoconstriction
_____ of small vessels decreases peripheral resistance, which lowers the arterial blood pressure
Vasodilation
The wall of the left ventricle is__ thick
15mm
The wall of the right ventricle is__ thick
5mm
The thickness of the ventricular wall reflects?
The pressure load on the ventricle
The pressure load on the left ventricle is the?
Aortic pressure
The pressure load on the right ventricle is the?
Pulmonary arterial pressure
Noises generated by the beating heart and the resultant flow of blood through it is called?
Heart sounds
In healthy adults, there are ____ normal heart sounds that occur in sequence with each heartbeat
2
The two heart sounds are?
Lib[S1]
Dub(dup)[S2]
The heart sounds are produced by the closing of the___ and ___ valves
AV
Semilunar
The amount of blood pumped out of each ventricle per minute is called?
Cardiac output
Cardiac output is expressed in two forms, namely?
Stroke volume
Minute volume
The unit for cardiac output is?
Liter(ml)/min
Cardiac output(ml/min) = Stroke volume(ml/beat) × ____
Heart rate(beats/min)
Average heart rate = ___
70bpm
Average stroke volume = ___
70-80 ml/beat
Average cardiac output =___
5000ml/minute
Cardiac output varies widely with the ___
Level of activity of the body
Four factors affecting cardiac output are?
Heart rate Force of contraction of heart Blood volume Venous return NB: they all increase or decrease cardiac output (direct variation)
Four factors affecting heart rate are?
Autonomic innervation
Hormones
Fitness levels
Age
Six factors affecting stroke volume are?
Heart size Fitness levels Gender Contractility[ESV] Preload(EDV) After load(resistance)
Stroke volume (SV) = EDV - ____
ESV
The volume of blood pumped out of each ventricle per beat or contraction is?
Stroke volume
As stroke volume increases, the cardiac output also ____
Increases
Stroke volume depends on?
End Diastolic Volume (EDV)
Contractility (ESV)
The stroke volumes for each ventricle are generally ____, both being approximately ____ in a 70kg man
Equal
70ml
Men, on average, have higher stroke volumes than women because?
Men have larger heart size than women
Stroke volume is regulated by three variables, namely?
EDV
Total peripheral resistance
Contractility
The volume of blood in the ventricles at the end of the diastole is?
EDV
EDV is sometimes called?
Preload
Stroke volume increases with increased?
EDV
Frictional resistance in the arteries is called?
Total peripheral resistance
Total peripheral resistance is ___ related to stroke volume
Inversely
Total peripheral resistance is also known as?
Afterload
The strength of ventricular contraction is called?
Contractility
Stroke volume increases as contractility ___
Increases
The percentage of EDV that is ejected per cardiac cycle is called?
Ejection fraction(EF)
__ = (SV/EDV) × 100
EF%
Normal ejection fraction is about?
50-65%
EDV is controlled by factors that affect?
Venous return
Veins are capacitance vessels, because they hold ____ of the total blood volume
2/3
Veins have high compliance, because they stretch more than arteries at a given ___
Pressure
Veins have ___ walls than arteries and maintain ___ pressure
Thinner
Lower
Five factors that affect venous return are?
Pressure difference between arteries and veins
Pressure difference in venous system
Sympathetic nerve activity
Pressure difference between abdominal and thoracic cavities
Blood volume
The pressure difference between arteries and veins is?
About 10mmHg
In the venous system, highest pressures are found in the?
Venules
In the venous system, lowest pressures are found in the?
Vena Cava
Sympathetic nerve activity stimulates ___ and lowers ___
Smooth muscle contraction
compliance
Six physiological factors that affect cardiac output are?
Age Gender: cardiac output is more in males than females Altitude Pregnancy Exercise Emotion
NB: All of the above are directly proportional to cardiac output
Six pathological factors that affect cardiac output are?
Hyperthyroidism (increase) Fever(increase) Hypothyroidism (decrease) Hypovolemia (decrease) Haemorrhage (decrease) Myocardial infarction (decrease)
Five ways to measure cardiac output are?
The Fick principle Dilution methods Doppler ultrasound method Impedance cardiography Pulmonary artery thermo dilution
Pulmonary artery thermo dilution is also known as?
Transright-heart Thermo dilution
Increased cardiac output increases?
Blood pressure
Factors that affect BP are?
Cardiac output Blood volume Peripheral resistance Blood viscosity Rigidity of blood vessel wall
For a typical , fit young person, their cardiac output may be about____ at the peak of exercise
20 litres/min
For a world class athlete in an endurance sport, the maximum cardiac output may be around?
35 litres/min
Maintaining a constant cardiac output around 5 litres/min under normal conditions and adjusting the cardiac output as per the physiological demands is?
Regulation of cardiac output
Cardiac output has to be regulated to?
Have an optimum cardiovascular efficiency
Two mechanisms of cardiac output regulation are?
By venous return
By nervous system
The force of contraction of a muscle fibre that is proportional to its initial length is called?
Starling’s law of muscle contraction
Within physiological limits, the heart pumps all the blood that returns to it by the way of veins is?
Frank-Starling Law
Increased blood volume= increased stretch of?
Myocardium
_____ takes a major role in the regulation of cardiac output
Autonomic nervous system
Increase in parasympathetic nervous system activity inhibits?
SA node
Increase in sympathetic nervous system activity stimulates?
SA node
Ventricular myocardium
Increase in sympathetic nervous system activity increases?
Cardiac output
Heart rate
Stroke volume
Force of muscle contraction
Increase in parasympathetic nervous system activity decreases?
Cardiac output
Heart rate
In healthy humans, the average cardiac outputs are ____ from one person to another
Constant
Multiple clinical abnormalities can cause either ____ cardiac outputs
High or low
High cardiac output is mostly caused by reduced?
Total peripheral resistance
Four conditions that reduce total peripheral resistance are?
BeriBeri
Arteriovenous Fistula
Hyperthyroidism
Anaemia
Two factors that cause low cardiac output are?
Abnormalities that cause the venous return to fall to low
Abnormalities that cause pumping effectiveness of the heart to fall to low
Systole is also called?
Contraction
Diastole is also called?
Relaxation
The performance of the human heart from the beginning of one heart beat to the beginning of the next is called?
Cardiac cycle
The duration of cardiac cycle is?
0.6-1second
Normal resting heart rate for children is?
70-100 beats/minute
Normal resting heart rate for adults is?
60-100 beats/minute
A well trained athlete may have a resting heart rate of?
40 beats/minute
Cardiac cycle = duration of beat(s)/ ______
heart rate (pulse)
The two events of the cardiac cycle are?
Atrial events
Ventricular events
Atrial events are divided into?
Atrial systole
Atrial diastole
Ventricular events are divided into?
Ventricular systole
Ventricular diastole
The three phases(order of activities) of the cardiac cycle are?
Atrial systole
Ventricular systole
Diastole of the whole heart
The subdivision of the cardiac cycle phases are?
Atrial systole Isovolumetric/Isometric contraction phase Rapid ejection phase Slow ejection phase Protodiastolic phase Isovolumetric/Isometric relaxation phase Rapid filling phase Slow filling phase
The cardiac cycle phase in which both atria contract to fill the ventricles with the remaining 25% blood volume is called?
Atrial systole
Atrial systole takes place in____ seconds
0.1
Atrial systole coincides with the ____ of the ventricles
Last rapid filling phase
The two effects of atrial systole are?
Intraatrial pressure
Intraventricular pressure
