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
The intraatrial pressure of the left atrium is?
7-8mmHg
The intraatrial pressure of the right atrium is
4-6mmHg
The effects of Intraventricular pressure include?
Decreasing Venous return
Narrowing of origin of great veins
Ventricular systole is divided into?
Isovolumetric/isometric contraction phase
Ventricular ejection
Ventricular systole takes place in ___ seconds
0.3
Ventricular ejection is divided into?
Rapid ejection phase
Slow ejection phase
In isovolumetric/isometric contraction, intraventricular pressure_____, AV valves ____, semilunar valves____ and the ventricles contracts as closed chamber
Rises
Closes
Aren’t open
In isovolumetric/Isometric contraction phase, there’s no change in?
Volume
In isovolumetric/Isometric contraction phase, there’s a sharp rise in?
Intraventricular pressure
Ventricular ejection phase begins with?
The opening of the semilunar valves
Ventricular ejection takes place in ____ seconds
0.25
In rapid ejection phase, ____ of stroke volume is ejected
2/3rd
In rapid ejection phase, the right ventricle’s ____ is less than the left, but the ____ is more
Velocity
Duration
Isovolumetric/Isometric contraction phase takes place in ____ seconds
0.05
Rapid ejection phase takes place in ___ seconds
0.1
Slow ejection phase takes place in _____ seconds
0.15
In slow phase, _____ of stroke volume is ejected
1/3rd
During diastole of the whole heart, both the atria and the ventricles are _____ at almost the same time
Relaxed
Atrial diastole occurs while ventricular systole is ____ and ventricular diastole is ____
Ending
Beginning
The protodiastolic phase takes place in ____ seconds
0.4
In the protodiastolic phase, ventricular systole ____, causing the ventricles to ___ and intraventricular pressure to____
Ends
Relax
Fall
In protodiastolic phase, the semilunar valves ____, causing the ____ heart sound and _____ in the pulse
Close
2nd
Dicrotic Notch(aortic notch)
A small downward deflection in the arterial pulse or pressure contour immediately following the closure of the semilunar valves is called?
aortic notch (dicrotic notch)
____ is sometimes used as a marker for the end of systole or the ejection period
Aortic notch(Dicrotic Notch)
Isovolumetric/isometric relaxation phase takes place in______ seconds
0.06
Isovolumetric/Isometric relaxation phase begins with?
The closure of the semilunar valves
Isovolumetric/Isometric relaxation phase ends with the?
Opening of AV valves
the short period in the cardiac cycle between the end of systole and the closure of the aortic valve marking the start of diastole is the?
Protodiastolic phase
The phase that begins after left atrial pressure has exceeded the pressure within the Left ventricle and the mitral valve opens, allowing passive blood flow into the Left ventricle is the?
Rapid filling phase
___ contributes the largest blood volume during filling
Rapid filling phase
The phase that occurs as the Left Ventricle pressure approaches the Left atrial pressure is called?
Slow filling phase
The Left atrium acts as a ____ during slow filling phase, allowing ____ to flow through the Left Atrium into the Left Ventricle
conduit
venous return
The phase that represents initial, rapid ejection of blood into the aorta and pulmonary arteries from the left and right ventricles, respectively when the intraventricular pressures exceed the pressures within the aorta and pulmonary artery, which causes the aortic and pulmonic valves to open is the?
Rapid ejection phase
In isovolumetric relaxation, what happens When the ventricular pressures drop below the diastolic aortic and pulmonary pressures (80 mmHg and 10 mmHg respectively),
the aortic and pulmonary valves close producing the second heart sound marking the beginning of diastole
The lateral pressure exerted by the moving column of blood on the walls of the arteries is called?
Arterial blood pressure
The unit of arterial blood pressure is?
mmHg
Three significance of arterial blood pressure are?
To ensure blood flows to various organs
Required to form urine
Required for the formation of lymph
The normal range of arterial blood pressure in adults is?
100/60 - 140/80 mmHg
The maximum B.P in the arteries attainable during systole is called?
Systolic B.P(S.B.P)
Normal systolic B.P ranges from?
100-140 mmHG
S.B.P s mainly contributed by?
Force of heart beat
Normal blood volume
Cardiac output
The minimum blood pressure obtained at the end of the ventricular diastole is called?
Diastolic B.P(D.B.P)
Normal diastolic B.P ranges from?
60-90mmHg
D.B.P represents a constant ____ on the arterial walls with little or no fluctuation at all
Load
D.B.P is an _____ to the peripheral resistance
Index
D.B.P decides the filling of the ____ system
Coronary
The difference between systolic and diastolic blood pressure is called?
Pulse pressure
Normal pulse pressure ranges between?
40-60mmHg
____= SBP - DBP
PP
Mean arterial blood pressure= DBP + ___pulse pressure
1/3
The average pressure in a patient’s arteries during one cardiac cycle is called?
Mean arterial pressure
The normal range of mean arterial blood pressure is?
70-100 mmHg
Mean arterial blood pressure (MABP or MAP) is the ____ mean and not the ______ mean
Arithmetic
Geometric
MAP is the arithmetic mean because?
The period of systole is 0.3 sec when compared to 0.5 sec of the diastole
Physiological factors that affect blood pressure are?
Age Sex Body build Exercise Emotions Meals Sleep Posture High altitude Pain etc
Males have _____ blood pressure than women before menopause, but after menopause women have ____ blood pressure than men
Higher
As we age there’s a reduction in elastic tissue in your arteries, causing them to become stiffer and less compliant thereby ____ blood pressure
Increasing
Normal Blood pressure of an adult is?
100/60 - 140/90 mmHg
Emotions increase blood pressure through a surge of _____ when you’re in a stressful situation
Hormones
Exposure to high altitude can affect the cardiovascular system by decreasing oxygen in the blood (acute hypoxia). It also increases demand on the heart, adrenaline release and pulmonary artery pressures thereby ____ blood pressure
Increasing
The gravitational effect at the density of normal blood is?
0.77 mmHg/cm
The blood pressure in any vessel below the heart level is ______, while the blood pressure in any vessel above the heart level _____
Increases
Decreases
Four determinants of arterial blood pressure are?
Cardiac output(CO)
Elasticity of blood vessels
Blood volume
Total peripheral resistance(TPR)
Increase in cardiac output leads to an _____ in arterial blood pressure
Increase
\_\_\_\_\_= CO × TPR \_\_\_\_\_ = HR ×SV × TPR
Arterial blood pressure (APB)
_____ makes blood vessels like tubes, causing them not to distend which greatly increases blood pressure significantly
Atherosclerosis
Increased blood volume increases CO which will _____ ABP
Increase
TPR is determined by?
Diameter of blood vessel (r)
Blood viscosity: RBC & plasma proteins
Polycythemia increases?
Viscosity
Hypoprotenemia decreases?
Viscosity
_____ = kABP/r
TPR
The two methods of recording B.P are?
Direct method
Indirect method
Indirect method is divided into?
Palpatory method
Auscultatory method
The Auscultatory method of measuring Blood pressure was introduced by the Russian physician______?
Korotkov
In the Auscultatory method, the sound at 120 mmHg is a?
Tapping sound
In the Auscultatory method, the sound at 110 mmHg is a?
Murmurish sound
In the Auscultatory method, the sound at 95 mmHg is a?
Banging sound
In the Auscultatory method, the sound at 85 mmHg is a?
Muffing sound
In the Auscultatory method, there is no sound at?
80 mmHg
The three regulations of arterial blood pressure are?
Short term regulation
Intermediate regulation
Long term regulation
Short term regulation includes?
Baroreceptor reflex
Chemoreceptor reflex
CNS ischemic response
Atrial reflexes
Baroreceptors are also known as?
Stretch receptors
Baroreceptors are found in the?
Carotid sinus
Aortic arch
Baroreceptors sense blood pressure in the ____ & ____
Aortic arch
Internal carotid
Baroreceptors send signals to the _______ of the medulla oblongata through the_____
Vasomotor center
Vagus & glossopharyngeal nerves
Baroreceptors respond to a rapidly changing B.P within the range of?
60-180mmHg
Decrease in Arterial blood pressure (ABP) will increase_____ and decrease _____
Heart rate(HR) & contractility Sympathetic vasoconstrictor tone(VC)
Increase in Arterial blood pressure (ABP) will increase_____ and decrease _____
Vasodilator
Heart rate
A change in posture from supine to erect will result in a drop in ABP where?
The head and upper part of the body
Baroreceptors are not suitable for long term regulation of ABP because?
They adapt rapidly to the new blood pressure level
The decrease in impulse discharge from the receptor despite persistence of the stimulus is termed?
Adaptation of a receptor
Cells stimulated by 02 lack, CO2 excess and H+ excess are called?
Chemosensitive cells
Chemosensitive cells are located in?
Carotid bodies & aortic bodies
The blood flow in chemosensitive cells is?
1200ml/min/g tissue
Chemosensitive cells easily detect changes in 02, CO2 and H+ because?
They have a very high blood flow
Chemoreceptors are activated when ABP drops below?
60mmHg
Chemoreceptors aren’t involved in ABP control at?
Normal range
Decrease in blood flow to chemoreceptors leads to decrease in?
O2
CO2
H+
Decrease in O2, CO2, H+ activates chemical signals which lead to?
Vasoconstriction
An emergency arterial pressure control system that rapidly prevents further decrease in ABP whenever blood flow to the brain decreases to lethal levels is called?
Ischaemic response
Ischaemic response is one of the most powerful activators of the?
Sympathetic vasoconstrictor system
When B.P drops below 20mmHg, it will lead to ____ of the vasomotor center
Cerebral ischemia
Cerebral ischemia is a strong ____ of blood vessels and the kidney
Vasoconstrictor
Low pressure receptors respond to changes in?
Blood volume
What happens if blood volume is increased?
Blood volume stretch of the atria increases
The exchange of fluid that occurs across the capillary membrane between the blood and the interstitial fluid is called?
Capillary fluid shift mechanism
Capillary fluid shift mechanism is controlled by?
Capillary blood pressure
Interstitial fluid pressure
Colloid osmotic pressure of the plasma
Low blood pressure helps to restore blood volume and blood pressure by?
Moving fluid from interstitial space into circulation
Long term regulation of blood pressure is carried out by the?
Kidneys
The kidney helps to regulate arterial blood pressure by?
Regulation of ECF volume
Renin-angiotensin system
The most important organs for long term control of blood pressure are the?
Kidneys
An excessive or increased discharge of water in urine from the body because of increased blood pressure is?
Pressure diuresis
An excessive or increased discharge of sodium in urine is?
Pressure natriuresis
The renal system is the most efficient long term regulation of blood pressure because?
It doesn’t adapt or loose it’s sensitivity to changes in arterial blood pressure
Regulation of ECF volume is done by two processes namely?
Pressure diuresis
Pressure natriuresis
When blood pressure increases, water is reabsorbed from the___1___ which increase____2___ and restores blood pressure
- Renal tubes
2. ECF volume, blood volume and cardiac output
When blood pressure increases, the kidneys excrete large amounts of___1__ and ___2___ by pressure diuresis and natriuresis
- Water and salt
2. Sodium
In renin-angiotensin mechanism, when blood pressure and ECF volume decreases, _____ from kidneys is increased
Renin secretion
Renin converts angiotensinogen into?
Angiotensin I
Angiotensin I is converted to angiotensin II by?
ACE(angiotensin converting enzyme)
Angiotensin II restores blood pressure in two ways namely?
- Causing constriction of arterioles
2. Stimulating the adrenal cortex
Three functions of angiotensin II in the body are?
Causes constriction of the arterioles to increase blood pressure and peripheral resistance
Causes constriction of the afferent arterioles in kidneys to reduce glomerular filtration
Stimulates the adrenal cortex to secrete aldosterone
Glomerular filtration reduction results to retention of water and salts which increases?
ECF volume and blood pressure to normal level
Aldosterone increases __1__ reabsorption from the ____2___ tubules
- Sodium
2. Renal
Sodium reabsorption is followed by ___1___ reabsorption, resulting in increased ____2___ to normal level
- Water
2. ECF volume, blood volume and blood pressure
Four actions of angiotensin II are?
Vasoconstriction
Aldosterone secretion
Stimulation of the thirst centre
Increased absorption of Na+ from PCT by direct effect
Some hormonal regulation of ABP are?
Thyroxine Histamine Angiotensin Serotonin ADH
Histamine regulates blood pressure by?
Dilating blood vessels, thereby increasing blood pressure
ADH regulates blood pressure by?
Helping the kidneys manage the amount of water in your body, thereby lowering blood pressure
A condition in which the force of the blood against the artery walls is too high OR blood pressure that is higher than 140/90 is called?
Hypertension
Hypertension is of two types namely?
Primary (90%)
Secondary(10%)
Six predisposing factors of hypertension are?
Obesity Smoking Alcoholism Hereditary Sedentary life Stress
Three causes of secondary hypertension are?
Renal eg Nephrotic syndrome
Endocrine eg Conns, Thyrotoxicosis
Vascular eg arteriosclerosis
Two methods of treating of hypertension are?
Lifestyle modification
Medications
4 ways of modifying your lifestyle to treat hypertension?
Cessation of smoking
Weight reduction
Programmed exercise
Diet high in K+
4 medications used to treat hypertension are?
Diuretics
Beta-blockers
Calcium antagonists
ACE inhibitors
The function of Diuretics are?
They increase urine volume
The function of beta-blockers are?
To Decrease heart rate
The function of calcium antagonists are?
To block Ca2+ channels
The function of ACE inhibitors is to
To inhibit angiotensin I conversion to angiotensin II
Four ways of preventing hypertension are?
Regular exercise
Stop smoking
Weight reduction
Reducing salt and fat intake
A condition in which the force of the blood against the artery walls is too low OR blood pressure that is lower than 100/60 is called?
Hypotension
5 Causes of hypotension are?
Haemorrhage Dehydration Diarrhea🤢 Hypothyroidism Adisson's disease
T
Adisson’s disease
A disorder in which the adrenal glands produce insufficient amounts of the hormone cortisol and sometimes aldosterone
Addison’s disease(hypocortisolism)
Three ways to treat hypotension are?
Blood transfusion
I.V fluids
Vasoconstrictors
The process of capturing or recording electrical activity or changes in the heart using an electrocardiograph is called?
Electrocardiography
The instrument or machine used to record electrical activities or changes in the heart is called?
Electrocardiograph
The graphical representation of all electrical activities or changes of the heart is called?
Electrocardiogram
Electrocardiograph is also known as?
Electrokardiograph(Dutch pronunciation)[ECG,EKG]
5 uses of electrocardiogram are?
Determining heart rate Diagnosing heart attack Determining heart rhythm Diagnosing Coronary artery disease Diagnosing ischemia
The electrocardiograph was invented in?
1903
The electrocardiograph was invented by?
Willem Einthoven
Willem Einthoven was a Dutch _____
Doctor and physiologist
The sinoatrial nodes has ____ bpm
60-100
The atrioventricular node has ____ bpm
60
The atrioventricular Bundle of His has _____ bpm
40-60
The left bundle branch and right bundle branch both have _____ bpm
30-40
The Purkinje fibres has ____ bpm
10-30
The SA node is also known as the?
Sinus node
The SA node is situated in the?
Upper part of the wall of the right atrium
The SA node is heart’s natural _____
Pacemaker
The function of the AV node is to?
Electrically connect the atria and the ventricles
Control the ventricles contraction
The function of the AV bundle of His is to
transmit the electrical impulse from the AV node to the Purkinje fibres of the ventricles.
The function of the SA node is to?
To control the contraction of the atria
The function of the left and right bundle branch is to?
Transmit electrical signals from the bundle of His to the Purkinje fibers.
The muscle cells that send signals to the rest of the heart muscle causing a contraction are called?
Conduction pathways of the heart
The function of the Purkinje fibres are to?
Maintain consistent heart rhythm
In conduction pathway, P wave is the?
Atrial depolarisation
In conduction pathway, PR interval is the?
Impulse from atria to ventricles
In conduction pathway, QRS complex is the?
Ventricular depolarisation
In conduction pathway, ST segment is the?
Isoelectric part of repolarisation
In conduction pathway, T wave is the?
Ventricular repolarisation
In conduction pathway, QT(U wave) interval is the?
Interval between ventricular depolarisation and repolarisation
The initiation of the contraction of the atrial musculature, which forces more blood flow across the open atrioventricular (AV) valves, leading to a rapid flow of blood into the ventricles is called
Atrial depolarization
The conduction of electrical impulses into the ventricle bypassing the AV-His Purkinje conduction system through the accessory pathway (AP) is called?
Ventricular depolarization
Electrocardiographic alterations, not related to cardiac electrical activity are called?
Electrocardiographic artifacts
Causes of electrocardiographic artifacts are?
Improper grounding
Patient movement
Loose or defective electrodes/apparatus
How many electrodes are used for 12-lead ECG?
Ten
Electrocardiograph electrodes consist of conducting __1__, embedded in the middle of an ___2___ onto which cables clip
- Gel
2. Adhesive pad
The areas for placement of electrodes are divided into two, namely?
Limb electrodes
Chest electrodes
The number of limb electrodes are?
4
The number of chest electrodes are?
6
The ECG detects and ____1___ tiny electrical charges on the skin causes when the heart muscle ___2__ during each heart beat
- Amplifies
2 . Depolarizes
The components of the conduction pathways are?
SA node AV node AV bundle of His Left bundle branch and Right bundle branch Purkinje Fibres
The steps in interpreting ECG are?
Rate Rhythm Cardiac Axis P-wave PR interval QRS complex ST segment QT interval( T and U wave) Other ECG signs
For the general interpretation of ECG, you read ____ at the bottom part of the ECG strip
Lead II(Rhythm strip)
Two ways of calculating rate in ECG are?
RATE = 300/ the number of BIG SQUARE between R-R interval RATE = 1500/ the number of SMALL SQUARE between R-R interval
The two types of rhythm in ECG are?
Ventricular rhythm
Atrial rhythm
Atrial rhythm is measured from the?
P-P interval on lead II
Ventricular rhythm is measured from?
R-R interval on lead II
The P wave is upright in?
Leads I and II
Normal duration of PR interval is?
3-5 small squares
ECG rhythm has a usual rate of?
60-99 bpm
Every P wave is followed by a?
QRS complex
Every QRS complex is preceded by a?
P wave
The sinus bradycardia normal rate is?
Below 60bpm
The sinus tachycardia normal rate is?
Above 100bpm
The general direction of the overall electrical activity of the heart is called?
Cardiac axis
Electrical impulse that travels towards the electrode produces an ____ deflection of the QRS complex
upright(positive)
Electrical impulse that travels away from the electrode produces a ____ deflection of the QRS complex
Negative
Electrical impulse that travels at a right angle to the lead produces a ____ wave
Biphasic
The P wave is always positive in ___ in NSR
Lead I and II
The P wave is always negative in ___ in NSR
Lead aVR
The P wave is commonly biphasic in?
lead V1
The long PR interval may indicate?
Heart block
Short PR interval may be due to disease like?
Wolf-Parkinson-White
The circulation of blood in the blood vessels that supply the heart muscle (myocardium) is called?
Coronary circulation
The vessels that deliver oxygen-rich blood to the myocardium are known as?
Coronary arteries
The vessels that remove the deoxygenated blood from the heart muscle are known as?
Cardiac veins
Coronary circulation consists of?
Arterial supply
Venous drainage
Lymphatic drainage
The cardiac muscle is supplied by two coronary arteries namely?
The right and left coronary arteries
Both coronary arteries arise from the ___1___ behind the cusps of the __2___ at the root of the of the ___3___
- Sinuses
- Aortic valves
- Aorta
The branches of the right coronary artery are?
Posterior interventricular artery Right marginal artery Right atrial artery Infundibular artery Nodal artery(in 60% of cases) Terminal artery
The branches of the left coronary artery are?
Anterior interventricular artery Circumflex artery Left atrial artery Pulmonary artery Terminal artery
The right coronary artery is _____ than the left coronary artery
Smaller
The right coronary artery arises from the?
Anterior coronary sinus
The right coronary artery anastomoses with the?
Left coronary artery
Three areas the right coronary artery supplies are?
A greater part of right ventricle and a small part of the left ventricle adjoining the posterior interventricular groove
Inter ventricular septum
Whole of the conduction pathway of the heart except a part of the left branch of the AV bundle
The large branches of the right coronary artery are?
Posterior interventricular artery
Right marginal artery
The small branches of the right coronary artery are?
Right atrial artery
Infundibular artery
Nodal artery
Terminal artery
The left coronary artery is ______ than the right coronary artery
Larger
The left coronary artery arises from the?
Left posterior aortic sinus
The large branches of the left coronary artery are?
Anterior interventricular artery
Circumflex artery
The small branches of the left coronary artery are?
Left atrial artery
Pulmonary artery
Terminal artery
The left coronary artery supplies the?
A greater part of the left ventricle and a small part of the left ventricle adjoining the anterior interventricular groove
Anterior part of interventricular septum
Part of the left branch of AV bundle
The two coronary arteries anastomose in the?
Myocardium
The anastomosis of the two coronary arteries is called?
Cardiac anastomosis
The coronary arteries anastomose with the?
Vasa vasorum of the aorta Vasa vasorum of pulmonary arteries Internal thoracic arteries The bronchial arteries Phrenic arteries
The anastomosis of the coronary arteries with other arteries of the heart and aorta is called?
Extra cardiac anastomosis
The other arteries and the aorta the coronary arteries anastomose with open up during?
Emergencies when the coronary arteries are blocked
The artery that gives the posterior interventricular artery determines?
Coronary dominance
Which artery determines the coronary dominance?
The artery that supplies the posterior third of the interventricular septum – the posterior descending artery (PDA) determines the coronary dominance
_____ is defined by the vessel which gives rise to the posterior descending artery (PDA), which supplies the myocardium of the inferior third of the interventricular septum
Coronary arterial dominance
What classifies the coronary circulation as “right dominant”?
The right coronary artery supplying the posterior interventricular artery
What classifies the coronary circulation as “left dominant”?
The circumflex artery supplying the posterior interventricular artery
What classifies the coronary circulation as “co dominant”?
The right coronary artery and the circumflex artery supplying the posterior interventricular artery
In _____of human beings, the right coronary artery is larger(right dominant) and supplies more blood to the heart than the left coronary artery
50-60%
In _____of human beings, the left coronary artery is larger(left dominant) and supplies more blood to the heart than the left coronary artery
15-20%
In ______ of human beings, both arteries supply almost equal amount of blood
20-30%
The function of the large coronary arteries are?
Lie on epicardial surface
Conduct blood with little resistance
Large coronary arteries are also called?
Epicardial coronary arteries
The function of the small coronary arteries is?
To regulate coronary blood flow
The small coronary arteries are divided into two, namely?
Subepicardial vessels
Subendocardial vessels
The principal resistance vessels of the heart are also called?
Small coronary arteries
The Venous drainage of the heart is by three means, namely?
Coronary sinus
Anterior cardiac veins
Venae cordis minimae
The largest vein of the heart situated in the left posterior coronary sulcus is called?
Coronary sinus
The coronary sinus is about____ long
2-3cm
The coronary sinus opens into the?
Posterior wall of the right atrium
The tributaries of the coronary sinus are?
Great cardiac vein Middle cardiac vein Small cardiac vein Posterior vein of left ventricle Oblique vein of left atrium (of Marshall) Right marginal vein
The great cardiac vein enters the?
Left end of the coronary sinus
The middle cardiac vein accompanies the ___1___ and joins the ____2___
- Posterior interventricular artery
2. right end of the Coronary sinus
The small cardiac vein accompanies the ____1___ and joins the __2___
- Right coronary artery
2. right end of the Coronary sinus
The posterior vein of left ventricle runs on the __1__ and ends in the __2___
- diaphragmatic surface of the Left ventricle
2. middle of the coronary sinus
The right marginal vein accompanies the?
Marginal branch of the right coronary artery
The oblique vein of the left atrium (of Marshall) runs on the 1 and joins the ___2___ and develops from the __3__
- Posterior surface of the left atrium
- Left end of coronary sinus
- Left common cardinal vein
3 to 4 small veins that run on the anterior wall of the right ventricle and opens directly into the right atrium are called?
Anterior cardiac vein
Venae cordis minimae is also called?
Smallest cardiac veins
Venae cardiacae minimae
Thebesian veins
Numerous small veins present in all 4 chambers of the heart which open directly into the cavities are called?
The venae cordis minimae
The venae cordis minimae or Thebesian venous network is considered an _____ of venous drainage of the myocardium
Alternative (secondary) pathway
The Thebesian venous network is named after?
German anatomist Adam Christian Thebesius(1708)
The lymphatics of the heart accompany the ___1___ and form two ___2__
- Coronary arteries
2. Trunks
The right lymphatic trunk ends in the?
Brachiocephalic nodes
The left lymphatic trunk ends in the _____ at the bifurcation of the trachea
Tracheobronchial lymph nodes
The resting coronary blood flow is?
∼225-250 ml min−1 (0.7-0.8- ml min−1 g−1 of heart muscle)
The resting coronary blood flow is___ of the total cardiac output
4-5%
In severe muscular exercise, coronary blood flow(CBF) may be increased to?
2 litres/minute
Five factors regulating coronary blood flow are?
Physical Chemical Neural Hormonal Reflex
The physical factors affecting CBF are?
Aortic blood pressure
Heart rate
Cardiac output
CBF is directly proportional to?
aortic blood pressure( especially the diastolic aortic pressure)
Most of CBF occurs during?
Diastole
When diastolic pressure decreases, the _____ decreases
CBF
Diastolic aorta pressure decreases because of?
Shock or aortic stenosis
Aortic incompetence
Coronary blood flow to the ___1___ is more severely impaired than the ___2___ of the ventricle
- endocardial regions
2. Epicardial regions
Excessive rise in heart rate eg during paroxysmal tachycardia will lead to decrease in?
Coronary filling(occurs mainly during ventricular diastole) CBF
CBF is directly proportional to?
Cardiac output
Increase or Decrease in cardiac output will lead to an increase or decrease respectively in?
CBF
Increased cardiac output will lead to an increase in __1__ + reflex inhibition of the __2__ which leads to___3__ and increases CBF
- Aorta BP
- Vagal vasoconstrictor tone (anrepis reflex)
- Coronary vasodilation
CBF occurs mainly during diastole due to __1__ during systole by the ___2__
- compression of the coronary blood vessels
2. Contracted muscle fibers
CBF is less during ___1__ than during __2__
- Systolic phases
2. Diastole phases
During systole, blood flow is minimal during?
isovolumetric contraction phase
blood flow is minimal during isovolumetric contraction phase because of the?
Compression of the coronary blood vessels with low aortic pressure
blood flow is maximal during isovolumetric relaxation phase because of the?
Dilation of the coronary blood vessels with high aortic pressure
Chemical factors are divided into?
Metabolic factors
Drugs
Increased cardiac metabolism increases?
CO2 K+ Lactic acid & adenosine in the cardiac muscle Coronary vasodilation CBF
Increased cardiac metabolism decreases?
O2
Hypoxia(O2 lack) is the most effective ______
Coronary vasodilator
Hypoxia produces coronary vasodilation through?
Direct action on coronary blood vessels
Release of chemical substances like adenosine(ATP), a potent coronary vasodilator
Some drugs used to increase CBF are?
Nitrites
Aminophylline
Caffeine etc are coronary vasodilator
Nervous factors are divided into?
Direct effect
Indirect effect
The direct effect is divided into two, namely?
Parasympathetic
Sympathetic
In direct effect, parasympathetic vagus has a very slight distribution to ___1___ so it’s stimulation has a slight __2__
- Coronary
2. Dilator effect
In direct effect, sympathetic stimulation causes slight direct ___1__ because both alpha and beta receptors exist in the ___2___
- Coronary constriction
2. Coronary vessels
Indirect effect is more important in control of ____ than the direct effect
CBF
In indirect effect, sympathetic stimulation increases __1__ , __2__ and __3__ leading to ___4__ of coronary blood vessels
- Heart rate
- Myocardial contractility
- Metabolism rate
- Dilation
In hormonal factor, thyroxine increases 1, which leads to increased __2__, which will in turn increase ___3___ and thus increases ___4__
- Cardiac output
- Metabolism
- Coronary vasodilation
- CBF
In hormonal factor, vasopressin (anti-diuretic hormone) will cause __1__ and decrease __2__
- Coronary vasoconstriction
2. CBF
Reflex control or factor is divided into two, namely?
Anrep’s reflex
Gastro - coronary reflex
In Anrep’s reflex, increased __1__ causes increased pressure in the __2__, leading to __3__ increase in the CBF eg during muscular exercise
- Venous return
- Right atrium
- Reflex
In Anrep’s reflex, increased __1__ causes increased pressure in the __2__, leading to __3__ increase in the CBF eg during muscular exercise
- Venous return
- Right atrium
- Reflex
In gastro-coronary reflex, distention of the stomach with heavy meal causes _____ of coronary blood vessels, thereby decreasing CBF
Reflex vasoconstriction
The capacity of the heart to maintain steady myocardial perfusion across a range of perfusion pressures is called?
Coronary autoregulation
The range of coronary autoregulation is?
60-140mmHg
The three mechanisms of coronary autoregulation are?
Myogenic response
Chemical theory
Endothelium derived relaxation factor(EDRF)
The mechanism by which coronary resistance vessels alter their diameter in response to pressure changes is the?
myogenic response
The decrease in perfusion pressure leading to increase in adenosine & decrease in oxygen which causes vasodilation and increased CBF is called?
Chemical theory
An increase in passive stretch, caused by increased perfusion pressure that causes active smooth muscle contraction is called?
Myogenic response
EDRF is a potent vasodilator, that causes ____1___ and increased ___2___
- Coronary dilation
2. Increased CBF
EDRF is secreted by?
Vascular endothelium
Vascular endothelium is stimulated by?
Increased distention force
Increased distention force is caused by?
Hypoxia
Muscular exercise etc
Severe chest pain Is also known as?
Angina pectoris
Angina pectoris is usually __1__ due to __2__ of the cardiac muscle
- Retrosternal (behind the sternum)
2. ischemia
Ischemia is caused by the?
Narrowing of the coronary arteries
Angina pectoris is due to accumulation of pain producing substances in the?
myocardium
Some pain producing substances are?
P factor
Lactic acid
Histamine
Kinins etc
Necrosis of a part of the myocardium due to severe & prolonged ischemia and occlusion of one of the coronary arteries or its branches is called?
Myocardial infarction
Occlusion of one of the coronary arteries or its branches is caused by?
Coronary thrombosis severe ischemia
Myocardial infarction produces chest pain more severe than that of __1__ and can’t be relieved by __2__
- angina pectoris
2. rest or coronary VD drugs
Myocardial infarction is usually complicated by?
Fatal ventricular fibrillation
____ is the narrowing (constriction) of blood vessels by small muscles in their walls
Vasoconstriction
A widening of blood vessels, usually near the surface of skin, leading to increased blood flow with flushing or warmth is called?
Vasodilation
