Useful for medical and biology students who want to study the cardiac cycle in a short time with big benefits !!
CVS physiology - Wigger Diagram - ECG of cardiac cycle - Heart sounds
Describe events in cardiac cycle.
Describe atrial, ventricular and aortic pressure changes during cardiac cycle.
Describe the changes in ventricular volume & stroke volume during cardiac cycle.
Relate ECG changes to the phases of cardiac cycle.
Describe the functions of cardiac valves and relate their state to the production of heart sounds during cardiac cycle.
med_students0
HEART RATE
REGULATION OF HEART RATE
VASOMOTOR CENTER – CARDIAC CENTER
MOTOR (EFFERENT) NERVE FIBERS TO HEART
FACTORS AFFECTING VASOMOTOR CENTER
for all medical & health care students
Cardiac cycle (The Guyton and Hall physiology)Maryam Fida
Sequence of events from the beginning of one systole to the beginning of next consecutive systole.
One heart beat consists of one systole and one diastole.
Each cardiac cycle is initiated by the cardiac impulse which originates from the SA node.
During each cardiac cycle, certain events occur in the heart and these include pressure changes, volume changes, production of heart sounds, closure and opening of heart valves and electrical changes in the heart.
Describe events in cardiac cycle.
Describe atrial, ventricular and aortic pressure changes during cardiac cycle.
Describe the changes in ventricular volume & stroke volume during cardiac cycle.
Relate ECG changes to the phases of cardiac cycle.
Describe the functions of cardiac valves and relate their state to the production of heart sounds during cardiac cycle.
med_students0
HEART RATE
REGULATION OF HEART RATE
VASOMOTOR CENTER – CARDIAC CENTER
MOTOR (EFFERENT) NERVE FIBERS TO HEART
FACTORS AFFECTING VASOMOTOR CENTER
for all medical & health care students
Cardiac cycle (The Guyton and Hall physiology)Maryam Fida
Sequence of events from the beginning of one systole to the beginning of next consecutive systole.
One heart beat consists of one systole and one diastole.
Each cardiac cycle is initiated by the cardiac impulse which originates from the SA node.
During each cardiac cycle, certain events occur in the heart and these include pressure changes, volume changes, production of heart sounds, closure and opening of heart valves and electrical changes in the heart.
Cardiac output by Dr. Amruta Nitin Kumbhar Assistant Professor, Dept. of Phys...Physiology Dept
Definition of cardiac output and related terms
Measurement of cardiac output
Variations in cardiac output
Regulation of cardiac output
Cardiac output control mechanisms
Role of heart rate in control of cardiac output
Integrated control of cardiac output
Heart–lung preparation
Cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat.
Cardiac events that occur from –
beginning of one heart beat to the beginning of the next are called the cardiac cycle.
This presentation describes the normal cardiac cycle referred to pressure-time curves for aorta, the left ventricle and left atrium, the electrocardiogram and the phonocardiogram.
Cardiac output by Dr. Amruta Nitin Kumbhar Assistant Professor, Dept. of Phys...Physiology Dept
Definition of cardiac output and related terms
Measurement of cardiac output
Variations in cardiac output
Regulation of cardiac output
Cardiac output control mechanisms
Role of heart rate in control of cardiac output
Integrated control of cardiac output
Heart–lung preparation
Cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat.
Cardiac events that occur from –
beginning of one heart beat to the beginning of the next are called the cardiac cycle.
This presentation describes the normal cardiac cycle referred to pressure-time curves for aorta, the left ventricle and left atrium, the electrocardiogram and the phonocardiogram.
CARDIAC CYCLE, ECG AND HEART SOUNDS.pptxthiru murugan
CARDIAC CYCLE, ECG AND HEART SOUNDS: BY Wincy Thirumurugan..
“Cardiac cycle refers to the series of events that take place when the heart beats.”
Each cycle is initiated by spontaneous contraction in the SA node and then transmit through the A-V bundle and branches into the ventricles results completion of one cycle.
EVENTS OR PHASES OF CARDIAC CYCLE: Diastolic phase (Diastole) in this phase the heart chamber are in the state of relaxation and fills with blood that receives from the veins [IVC, SVC,PULMONARY VEINS]
Systolic phase (Systole) in this the heart chambers are contracting and pumps the blood towards the periphery via the arteries. [ Pulmonary artery and aorta]
PHASES OF THE CARDIAC CYCLE
The different phases of the cardiac cycle involve:
Atrial diastole - Atrial relaxation
Atrial systole -Atrial contraction
Isovolumic relaxation -ventricular relaxation in the early phase but blood will not move and the Atrio ventricular valves will be closed
Ventricular filling - ventricular relaxation, the Atrio ventricular valves will be open allows filling blood in the ventricles
Isovolumic contraction of ventricle – ventricular systole in the early phase but no movement of the blood. The semilunar valves will be closed.
Ventricular ejection -ventricular contraction and send blood out of the ventricles through opened semilunar valves.
6. Ventricular Filling Stage: second phase. Rapid Filling, Slow Filling & Last Rapid Filling Duration of Cardiac Cycle:
In a normal person, a heartbeat is 72 beats/minute.
An Electrocardiogram (ECG) is a medical test that detects cardiac (heart) abnormalities by measuring the electrical activity generated by the heart as it. The machine that records the patient’s ECG is called an electrocardiograph.
contracts.
PLACEMENT OF ECG LEADS
ECG WAVES:
The P wave is caused by spread of depolarization through the atria, After the onset of the P wave, The QRS waves Occurs as a result of electrical depolarization of the ventricles, the ventricular T wave represents the stage of repolarization of the ventricles, The 'U' wave is a wave comes after the T wave of ventricular repolarization and may not always be observed.
HEART SOUNDS: First Heart Sound (S1)
The first heart sound results from the closing of the mitral and tricuspid valves. Second Heart Sound (S2): The second heart sound is produced by the closure of the aortic and pulmonic valves. Third Heart Sound (S3):
The third heart sound, also known as the “ventricular gallop,” occurs just after S2 when the mitral valve opens, allowing passive filling of the left ventricle. The S3 sound is actually produced by the large amount of blood striking a very compliant LV.
[Compliance heart means how easily the chamber of heart or the lumen of blood vessels expands when it is filling with the blood]
Fourth Heart Sound (S4):
The fourth heart sound, also known as the “atrial gallop,” occurs just before S1 when the atria contract to force blood into the LV.
Medical science of cardiovascular system. It is the importance system in the human body. Blood is a specialised fruit can keep tissue which is circulated by cardiovascular system. Other system are respiratory system nervous system, gastrointestinal system . But cardiovascular system is the important system in our human body. Which involved heart
single cardiac cycle includes all of the events associated with one
heartbeat. Thus, a cardiac cycle consists of systole and diastole of the
atria plus systole and diastole of the ventricles.
Cardiac cycle and how the different chambers of the heart fill. We talk about the ventricular fillings and how diastole and systole work.
How pressure changes during all cycles
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
2. The Main Objectives
• Introduction tothecardiac cycle
• Whatis the cardiac cycle ?
• Carl J.Wigger’sDiagram!
• The mechanicaleventsandphases of cardiac cycle :
• ✔ Describe the cardiac cycle in terms of systole and diastole of the
atriaand ventricles.
• ✔ Explainhow the pressure differences within the heart chambers are
responsible for blood flow during the cardiaccycle.
• Heart sounds
3. Pressure Gradientsand volume
• A fluid flows only if it is subjected to more pressure at one
point thanatanother. The differencecreates apressure
gradient,and fluidsalways flow down theirpressure
gradients, from thehigh pressure point to the low-pressure
point
the greater the volume, the lower the pressure, and vice versa
4. Think aboutit, if you
pusha smaller amount
of fluidintoa larger
area, youhave less
pressure thanif you
push a large amount of
fluidintoa smaller area
6. Question ?
• Why there is a bicuspid valve in the left
side of the heart and a tricuspid valve in
the right side of the heart ?
• When did the First Cardiac cyclestart ?
And how ?
7. OverviewOn Fetal CardiacCycle
In a fetus, the resistance to blood
flow through the pulmonary
circulation is quite high, because
hypoxia (low oxygen) stimulates
smooth muscle contraction in
pulmonary arterioles, producing
vasoconstriction. (This differs
from systemic arterioles, which
dilate in response to hypoxia.)
8. • The high resistance in the fetal
pulmonary circulation causes blood
to pass from the higher pressure of
the right ventricle into the left
ventricle through an opening in the
interatrial septum calledthe
foramenovale . The pressure
difference also causes blood to be
shunted (diverted) from the
pulmonary to the systemic
circulation through a connection
between the pulmonary trunk and
aorta calledthe ductus arteriosus
9. • These shunts normally close after
birth. When the newborn breathes,
the blood oxygen levels suddenly
become higher. Because of
differing responses of the smooth
muscle cells to increased oxygen,
the rise in oxygen normally causes
vasodilation and thus increased
blood flow in the pulmonary
vessels, but contraction (and thus
closing) of the ductus arteriosus. If
the foramen ovale and ductus
arteriosus remain open (are patent)
after birth, murmurs can result.
10. Cardiac Cycle
the human heart has periodsof contraction(during which
bloodis pumped intothe large arteries)thatalternate
withperiods of relaxation(during whichbloodfills the
heart). These contractionand relaxationperiodsoccur in
cycles known as the cardiaccycles. each of which consist
ofaperiodofcontractioncalledsystole followedbya
periodofrelaxationcalleddiastole.
11. Cardiaccycle is defined as the sequence of
coordinatedevents taking place inthe heart during
each beat
Events of cardiaccycle are
classifiedinto two:
1. Atrialevents
2. Ventricularevents.
12. Durations inthe cardiac cycle
The total durationofthecardiaccycle,includingsystole and
diastole,is the reciprocal of the heart rate. For example, if heart
rate is72 beats/min, the duration of the cardiac cycle is 1/72
min/beat—about 0.0139 minutes per beat, or 0.833 second per
beat.
13. „VENTRICULAREVENTS
Ventricular events are dividedinto two
divisions:
1. Ventricular systole = (0.3) sec
2. Ventricular diastole = (0.5) sec
ATRIAL EVENTS
Atrial events are dividedinto two
divisions:
1. Atrial systole = (0.1) sec
2. Atrial diastole = (0.7) sec.
NOTE : In clinical practice, the term
‘systole’ refers to ventricular systole
and ‘diastole’ refers to ventricular
diastole.
14. Ventricular systole is divided into two
subdivisions and ventricular diastole is
divided intofivesubdivisions:
Ventricular Systole
Time (second)
1. Isometric contraction = 0.05
2. Ejection period = 0.22
Ventricular Diastole
1. Protodiastole = 0.04
2. Isometric relaxation= 0.08
3. Rapid filling= 0.11
4. Slow filling = 0.19
5. Last rapidfilling = 0.11
15. The Phases of The Cardiac Cycle
1) Atrial Systole (Last rapid filling phase )
2) Isometric ( Isovolumic ) contraction period
3) Ejection period ( Rapid , Slow )
4) Protodiastole
5) Isometric ( Isovolumic ) relaxation period
6) Rapid fillingphase
7) Slow ( reduced ) fillingphase
16.
17. A Wiggers diagram is a
standard diagram used in
cardiac physiology named
after Dr. Carl J. Wiggers
19. Pressure and volume changes
• Ventricles:
About 25 % of the ventricular filling volume is
ejected from the atrium to the ventricle. Intra-
ventricular pressure increase slightly .
end-diastolicvolume = 110 to 120 milliliters
• Atria
The atrial contraction causes a rise in the atrial
pressure which produces the a wave .
• Arteries
The pressure in arteries of both systemic and
pulmonary circulations decreases constantly
20. Electrocardiogram
• Theatrialdepolarization is completed and theend of theP
waveappears at the beginningof the atrial systole.
Subsequently,the depolarization spreads from theatria to
theatrioventricular node and thePR segment is visible in
theECG
21. Heart sound
• The fourthheart sound is a soft sound due to an increase in
theventricular pressure following anatrial systole. It very
rarely occurs in a healthyperson. Under pathological
conditions this sound is present owing to an increase in intra-
atrialpressure or lower compliance of theventricle (e.g.in
ventricular hypertrophy).
22. Phase 2 : Isovolumetric contraction Period
• is thefirstphaseofventricular systole.(
0.05second )
• Immediatelyaftera ventricular
contraction begins,thepressure in the
ventriclesexceedsthepressure in the
atriaand thus the atrioventricular
valves shut.The semilunarvalves are
closedbecause theventricular pressure
islowerthan thatinthe aortaand the
pulmonaryartery
23. Pressure and volume changes
• Ventricles
The ventricular pressure rises considerably
without any change in the ventricular blood
volume
• The blood volumein the ventricles equals
tothe end-diastolic volume
• Atria
The atrioventricular valves are bulged backward
into the atria because of increasing pressure in
the ventricles. This event causes the c wave
• Arteries
Pressures in arteries of both systemic and
pulmonary circulations decrease constantly
24. Electrocardiogram
• The depolarization spreads from theatrioventricular node to
theseptumand thewalls of both ventricles throughthe
bundle of His and Purkinjefibres . The ventricular
depolarization causes theQRS complex in the ECG
25. Heart sound
• During theisovolumic contraction, the first heart sound
appears . This sound is caused by vibrations of the
atrioventricularvalves, the adjacent myocardium and blood
due to the closure of theatrioventricular valves
26. Phase 3 : Ejection
• Due to the opening of semilunar
valves and isotonic contraction of
ventricles, blood is ejected out of both
the ventricles. Hence, this period is
called ejection period. ( 0.22 second )
• Ejection period is of two stages:
• 1) First Stage or Rapid Ejection Period
( 0.13 second )
• 2) Second Stage or Slow Ejection
Period ( 0.09 second )
27. Pressure and volume changes
• Ventricles
During the first part of the ejection, the ventricular pressure rises and blood
is intensively ejected to the arteries – rapid ejection. As the blood volume
in the ventricles decreases, the ventricular pressure starts to decline in the
second part of this phase . The pressure gradient between ventricles and
arteries decreases and blood is ejected more slowly – decreased or slow
ejection. The maximum ventricular pressure at the top of the ejection
reaches 120 mmHg and 25 mmHg in the left and right ventricles,
respectively. This peak value is calledsystolic pressure.
28. • Atria
Asthe ventriclescontract theyalsoshorten.
Theshortening ventricleselongate the
atriaand thebig veins, loweringtheir
pressure. This pressure decrease is
representedbythe x wave.
• Arteries
Theblood pressure inthe big arteriesrises
due to rapidejection toreachthe
maximum value of120 mmHgand 25
mmHg inthe aortaand the pulmonary
artery,respectivelyDuring the slow
ejection,the bloodpressure in the
systemic andpulmonary circulations
startstodropprogressively.
29. TheEnd –SystolicVolume
• as the ventriclesemptyduring systole, the
volume decreases about 70 milliliters,
whichiscalled the stroke volume output.
The remainingvolume ineachventricle,
about 40 to 50 milliliters,is calledthe end-
systolic volume. The fractionofthe end-
diastolic volume that isejectedis called the
ejection fraction—usually equal toabout
0.6(or 60percent). Whentheheart
contracts strongly,the end-systolic volume
maydecrease toas littleas 10 to 20
milliliters.Conversely, when largeamounts
ofblood flowinto the ventriclesduring
diastole, theventricularend-diastolic
volumescan become as greatas 150to
180millilitersin the healthyheart
30. Electrocardiogram
• The ventricles are completely depolarized at the beginningof
theejection– segmentST in theECG. The T wave appears
due to the ventricularrepolarization in thesecond half of this
phase
31. Phase 4 : Protodiastole
• Protodiastoleis thefirststage
ofventricular diastole,hence
thenameprotodiastole.
Durationofthis periodis
0.04second. Due tothe
ejectionofblood,the
pressure in aorta and
pulmonaryartery increases
and pressure in ventricles
drops.
32. Phase 5 : Isovolumetricrelaxationperiod
• At theend of systole, the
ventricles relax and the
ventricular pressure decreases
rapidly. Due to theblood inertia,
theblood flows out of the
ventricles (for a short time) even
whenthe pressure in large
arteries exceeds the ventricular
pressure. 0.08 second
33. Pressure and volume changes
• Ventricles
The ventricles relaxwithoutchangingbloodvolume
in ventricles –theisovolumicrelaxation.The
bloodvolumein each ventricle equalstothe
end-systolicvolume (about60ml).
• Atria
Bloodflowsfromthe veins totheatriawhile the
atrioventricularvalves areclosed.Theatrial
pressureincreases toproducethe vwave.
• Arteries
The decreasein thearterialpressureis interruptedby
thedicroticnotchthatis seen in the aorticpulse.
It is amomentarypressure increasecausedbya
shortperiodofbackwardbloodflow
immediately beforetheclosureofthe semilunar
valves
35. Heart sound
• During theisovolumic relaxation, thesecond heart sound
appears . This sound is caused by vibrations of thesemilunar
valves, theadjacent myocardium and blood due to theclosure
of thesemilunarvalves.
36. Phase 6 : Rapid Ventricular Filling
• As soon as theventricular
pressure fallsbellow the atrial
pressure, the atrioventricular
valves open. Blood flows rapidly
from the atria to the ventricles.
The semilunarvalves are closed
( 0.11 second )
37. Pressure and volume changes
• Ventricle
Although the ventricular volume increases, the
ventricular pressure is not changed
significantly due to the ventricular
relaxation .
• Atria
The negative y wave is caused by the blood
evacuation from the atria to the ventricles.
Arteries
The minimum pressure within one cardiac cycle
called diastolic pressure is about 80 mmHg
and 8 mmHgin the systemic and the
pulmonary circulations, respectively
39. Heart Sound
• Thethird heart sound, which occurs rarely, is probably caused
by therapid blood flow
40. Phase 7 : Slow Ventricular Filling
• Theatrioventricular valves remain open whilethesemilunar
valves are closed.
41. Pressure and Volumechanges
• Ventricles
During the middle part of a diastole a
small volume of blood flows into the
ventricles. This is the blood flowing
from veins and passing the atria to fill
the ventricles. The pressure in both
ventricles is close to zero .
• Arteries
The pressures in arteries of both systemic
and pulmonary circulations decrease
constantly
42. Electrocardiogram
• At theend of slow ventricular filling,depolarization spreads
from sino-atrialnode in all directions over the atria to
produce theP wave in ECG
44. • 1. Stenosis
• Stenosismeans narrowing of heart valve. Bloodflows
rapidlywith turbulence throughthe narrow orificeof the
valve, resultingin murmur.
• 2.incompetence
• Incompetence refers to weakening of the heart valve.
When the valve becomes weak, it cannotclose properly. It
causes back flow of blood,resultingin turbulence. This
diseaseisalsocalledregurgitationor valvularinsufficiency.
45. • PHYSIOLOGICAL VARIATIONS
• 1. Age
• 2. Sex
• 3. Body build
• 4. Diurnal variation
• 5. Environmental temperature
• 6. Emotional conditions
• 7. After meals
• 8. Exercise
• 9. High altitude
• 10. Posture
• 11. Pregnancy
• 12. Sleep
PATHOLOGICAL VARIATIONS
1. Fever: Due to increased oxidative
processes
2. Anemia: Due to hypoxia
3. Atrial fibrillation: Because of
incomplete fillingof ventricles
4. Congestive cardiac failure: Because of
weak contractions of heart
5. Shock: Due to poor pumping and
circulation
6. Hemorrhage: Because of decreased
blood volume.