The document summarizes key aspects of heart anatomy and function. It describes the heart as a four-chambered pump made of cardiac muscle that circulates blood throughout the body. The two upper chambers are the atria which receive blood, and the two lower chambers are the ventricles which pump blood out of the heart. The heart has valves that allow blood to flow in one direction, and an electrical conduction system that coordinates contractions and pumping. The heart pumps deoxygenated blood to the lungs and oxygenated blood to the rest of the body in continuous cycles to supply tissues with oxygen and nutrients.
Haemodynamic data can be acquired in many ways. However we obtain the raw data we still have a big problem…
What do all these figures mean? How can we put it all together to help our patients?
Associate Professor Brendan E. Smith.
School of Biomedical Science, Charles Sturt University,
Specialist in Anaesthesia and Intensive Care, Bathurst Base Hospital, Bathurst, NSW, Australia
Haemodynamic data can be acquired in many ways. However we obtain the raw data we still have a big problem…
What do all these figures mean? How can we put it all together to help our patients?
Associate Professor Brendan E. Smith.
School of Biomedical Science, Charles Sturt University,
Specialist in Anaesthesia and Intensive Care, Bathurst Base Hospital, Bathurst, NSW, Australia
Observatorio Exterior de noviembre de 2016. Una publicación con artículos de opinión sobre temas de la actualidad internacional elaborado por el Servicio de Riesgo País de CESCE.
¡Si nos apoyamos en nuestra propia prudencia y no obedecemos a la voz de Su Espíritu para que nos guíe en todo momento, corremos el riesgo de errar el blanco de Dios, lo cual es muy peligroso!
ECG interpretation in a simple method ppt.
out lines :
Anatomy of the Heart
The Cardiovascular System
Physiology of the Heart
Electrical Conduction System of the Heart
The Electrocardiogram (ECG):-
Chest Leads
Recording of the ECG
Components of an ECG Tracing
ECG Interpretation :-
Sinoatrial (SA) Node Arrhythmias
Atrial Arrhythmias
Ventricular Arrhythmias
Atrioventricular (AV) Blocks
Artificial Cardiac Pacemakers
The 12-Lead ECG and M.I
Cardiac Emergency Medications
Cardiovascular physiology for university studentsItsOnyii
A detailed pdf document on cardiovascular physiology for university students including structure and functions of heart, Electrocardiogram, echocardiography, chest and limb leads, Diseases and disorders of the heart.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
2. THE HEART
• Heart is major organ of human body,
• It pumps blood throughout the whole body,
3. (1) Cardiovascular Function
• Cardiovascular = Heart, Arteries, Veins, Blood
• Function:Function:
–Transportation
–Blood = transport vehicle
–Carries oxygen, nutrients, wastes, and
hormones
–Movement provided by pumping of heart
4. (2) Cardiac Tissues
• Outermost = Pericardium & Epicardium
– Pericardium is a membrane anchoring heart to
diaphragm and sternum
– Pericardium secretes lubricant (serous fluid)
– Epicardium is outermost muscle tissue
• Middle = Myocardium
– Contains contractile muscle fibers
• Innermost = Endocardium
– Lines Cardiac Chambers
5.
6.
7. Location of the Heart
• The heart is located between the lungs
behind the sternum and above the
diaphragm.
• It is surrounded by the pericardium.
• Its size is about that of a fist, and its
weight is about 250-300 g.
• Its center is located about 1.5 cm to the
left of the midsagittal plane.
9. Anatomy of the heart
• The walls of the heart
are composed of
cardiac muscle, called
myocardium.
• It consists of four
compartments:
– the right and left atria
and ventricles
10. (3) Cardiac Chambers
• Human heart has 4 chambers
– 2 Atria
• Superior = primary receiving chambers, do not actually
pump
• Blood flows into atria
– 2 Ventricles
• Pump blood
• Contraction = blood sent out of heart + circulated
• Chambers are separated by septum…
– Due to separate chambers, heart functions as
double pump
11. The Heart Valves
• The tricuspid valve regulates blood
flow between the right atrium and right
ventricle.
• The pulmonary valve controls blood
flow from the right ventricle into the
pulmonary arteries
• The mitral valve lets oxygen-rich blood
from your lungs pass from the left
atrium into the left ventricle.
• The aortic valve lets oxygen-rich blood
pass from the left ventricle into the
aorta, then to the body
12. Blood circulation via heart
• The blood returns from the systemic circulation to
the right atrium and from there goes through the
tricuspid valve to the right ventricle.
• It is ejected from the right ventricle through the
pulmonary valve to the lungs.
• Oxygenated blood returns from the lungs to the
left atrium, and from there through the mitral valve
to the left ventricle.
• Finally blood is pumped through the aortic valve to the
aorta and the systemic circulation..
15. (4) Pulmonary Circulation
• Pulmonary = Deoxygenated Blood
• Involves Right Side of Heart
• Pathway:Pathway:
1. Superior / Inferior Vena Cava
2. Right Atrium Tricuspid Valve
3. Right Ventricle Pulmonary Semilunar Valve
4. Left Pulmonary Artery
5. Lungs
16.
17. (5) Systemic Circulation
• Systemic = Oxygenated Blood
• Involves Left Side of Heart
• Pathway:Pathway:
1. Left Pulmonary Vein
2. Left Atrium Bicuspid Valve
3. Left Ventricle Aortic Semilunar Valve
4. Aorta
5. All Other Tissues
18.
19.
20. (6) Cardiac Valves
[4 main valves]
• When the heart is relaxed…
– Blood passively fills atrium
– Flows right past tricuspid / bicuspid valves
– Semilunar Valves remain shut
• When the heart contracts (pumps)…
– Tricuspid / Bicuspid valves swing up and shut
– Blood ejected out of ventricle
– Semilunar Valves open up
21.
22. Electrical activation of the heart
• In the heart muscle cell, or myocyte,
electric activation takes place by means of
the same mechanism as in the nerve cell,
i.e., from the inflow of Na ions across the
cell membrane.
• The amplitude of the action potential is
also similar, being 100 mV for both nerve
and muscle.
23. • The duration of the cardiac impulse is,
however, two orders of magnitude longer
than in either nerve cell or sceletal muscle
cell.
• As in the nerve cell, repolarization is a
consequence of the outflow of K ions.
• The duration of the action impulse is about
300 ms.
25. Mechanical contraction
of Cardiac Muscle
• Associated with the electric activation of cardiac
muscle cell is its mechanical contraction,
which occurs a little later.
• An important distinction between cardiac muscle
tissue and skeletal muscle is that in cardiac muscle,
activation can propagate from one cell to another
in any direction.
26. Electric and mechanical activity
in
(A) frog sartorius muscle cell,
(B) frog cardiac muscle cell,
(C) rat uterus wall smooth
muscle cell.
27. The Conduction System
• Electrical signal begins in the sinoatrial
(SA) node: "natural pacemaker."
–causes the atria to contract.
• The signal then passes through the
atrioventricular (AV) node.
–sends the signal to the ventricles via the
“bundle of His”
–causes the ventricles to contract.
29. Conduction on the Heart
• The sinoatrial node in humans is in the shape of a crescent and is about
15 mm long and 5 mm wide.
• The SA nodal cells are self-excitatory, pacemaker cells.
• They generate an action potential at the rate of about 70 per minute.
• From the sinus node, activation propagates throughout the atria, but
cannot propagate directly across the boundary between atria and
ventricles.
• The atrioventricular node (AV node) is located at the boundary between
the atria and ventricles; it has an intrinsic frequency of about
50 pulses/min.
• If the AV node is triggered with a higher pulse frequency, it follows this
higher frequency. In a normal heart, the AV node provides the only
conducting path from the atria to the ventricles.
30. • Propagation from the AV node to the ventricles is provided by a
specialized conduction system.
Proximally, this system is composed of a common bundle, called the
•bundle of His (after German physician Wilhelm His, Jr., 1863-1934).
• More distally, it separates into two bundle branches propagating
along each side of the septum, constituting the right and left bundle
branches. (The left bundle subsequently divides into an anterior and
posterior branch.)
• Even more distally the bundles ramify into Purkinje fibers (named
after Jan Evangelista Purkinje (Czech; 1787-1869)) that diverge to the
inner sides of the ventricular walls.
• Propagation along the conduction system takes place at a relatively
high speed once it is within the ventricular region, but prior to this
(through the AV node) the velocity is extremely slow.
31. • From the inner side of the ventricular wall, the many
activation sites cause the formation of a wavefront
which propagates through the ventricular mass toward
the outer wall.
• This process results from cell-to-cell activation.
• After each ventricular muscle region has depolarized,
repolarization occurs.
Propagation on ventricular wall
33. Electrical events in the heart
SA node impulse generated 0 0.05 70-80
atrium, Right depolarization *) 5 P 0.8-1.0
Left depolarization 85 P 0.8-1.0
AV node arrival of impulse 50 P-Q 0.02-0.05
departure of impulse 125 interval
bundle of His activated 130 1.0-1.5
bundle branches activated 145 1.0-1.5
Purkinje fibers activated 150 3.0-3.5
endocardium
Septum depolarization 175 0.3 (axial) 20-40
Left ventricle depolarization 190 -
QRS 0.8
epicardium depolarization 225 (transverse)
Left ventricle depolarization 250
Right ventricle
epicardium
Left ventricle repolarization 400
Right ventricle repolarization
T 0.5
endocardium
Left ventricle repolarization 600
*) Atrial repolarization occurs during the ventricular depolarization; therefore, it is not normally seen in the electrocardiogram.
37. Electric field of the heart on the surface of the thorax, recorded by
Augustus Waller (1887).
The curves (a) and (b) represent
the recorded positive and negative
isopotential lines, respectively.
These indicate that the heart is a
dipolar source having the positive
and negative poles at (A) and (B),
respectively.
The curves (c) represent the
assumed current flow lines..
38. Lead Vector
• The potential Φ at point P due to any dipole p can be
written as
The vector c is the lead vector. Note that the value of
the lead vector is a property of the lead and volume
conductor and does not depend on the magnitude and
direction of the dipole p.
zzyyxx pcpcpc ++=φ
pc ⋅=φ
39. Extending the concept
of lead vector
• Unipolar lead:
measuring the voltage
relative to a remote
reference.
• Bipolar lead: formed
by a lead pair and is
the voltage between
any two points:
pc
pcc
V
pc
ij
ji
jiij
ii
⋅=
⋅−=
−=
⋅=
)(
φφ
φ
40. The 10 ECG leads of Waller.
Einthoven limb leads
(standard leads) and
Einthoven triangle.
The Einthoven triangle is an
approximate description of
the lead vectors associated
with the limb leads.
41. Limb leads
• The Einthoven limb leads (standard leads) are defined in the following way:
Lead I: VI = ΦL - ΦR
Lead II: VII = ΦF – ΦR
Lead III: VIII = ΦF - ΦL
where VI = the voltage of Lead I
VII = the voltage of Lead II
VIII = the voltage of Lead III
ΦL = potential at the left arm
ΦR = potential at the right arm
ΦF = potential at the left foot
• According to Kirchhoff's law these lead voltages have the following relationship:
VI + VIII = VII
hence only two of these three leads are independent.
pc
pc
pc
FF
LL
RR
⋅=
⋅=
⋅=
φ
φ
φ
42. Standard lead vectors form an equilateral triangle
0
0
)(
)(
)(
=−+
=−+
⋅=⋅−=
−=
⋅=⋅−=
−=
⋅=⋅−=
−=
IIIIII
IIIIII
IIILF
LFIII
IIRF
RFII
IRL
RLI
ccc
VVV
pcpcc
V
pcpcc
V
pcpcc
V
φφ
φφ
φφ
46. The Wilson central terminal
(CT) is formed by
connecting a 5 k resistance
to each limb electrode and
interconnecting the free
wires; the CT is the
common point.
The Wilson central terminal
represents the average of
the limb potentials.
Because no current flows
through a high-impedance
voltmeter, Kirchhoff's law
requires that
IR + IL + IF = 0.
47. (A) The circuit of the Wilson central terminal (CT).
(B) The location of the Wilson central terminal in the image space
(CT'). It is located in the center of the Einthoven triangle.
48. Additional limb leads
• Three additional limb
leads VR, VL, and VF
are obtained by
measuring the
potential between
each limb electrode
and the Wilson
central terminal.
3
2
3
2
3
2
LRF
CTLL
LRF
CTRR
LRF
CTFF
V
V
V
φφφ
φφ
φφφ
φφ
φφφ
φφ
+−−
=−=
−+−
=−=
−−
=−=
49. Goldberger Augmented leads
• Goldberger observed that the
signals from the additional limb
leads can be augmented by
omitting that resistance from the
Wilson central terminal which is
connected to the measurement
electrode.
• The aforementioned three leads
may be replaced with a new set of
lead that are called augmented
leads because of augmentation of
the signal.
• The augmented signal is 50%
larger than the signal with the
Wilson ventral terminal chosen as
reference.
2
2
2
2
2
2
/
/
/
LRF
aVCTLL
LRF
aVCTRR
LRF
aVCTFF
L
F
F
V
V
V
φφφ
φφ
φφφ
φφ
φφφ
φφ
+−−
=−=
−+−
=−=
−−
=−=
50. (A) The circuit of the Goldberger augmented leads.
(B) The location of the Goldberger augmented lead vectors in the
image space.
51. Precordial Leads
• For measuring the
potentials close to the
heart, Wilson introduced
the precordial leads
(chest leads) in 1944.
These leads, V1-V6 are
located over the left chest
as described in the figure.
52. The 12-Lead System
• The most commonly used clinical ECG-system,
the 12-lead ECg system, consists of the
following 12 leads, which are:
654321 ,,,,,
,,
,,
VVVVVV
aVaVaV
IIIIII
FLR
53. The projections of
the lead vectors of
the 12-lead ECG
system in three
orthogonal planes
(when one
assumes the
volume conductor
to be spherical
homogeneous and
the cardiac source
centrally located).
Editor's Notes
Four types of valves regulate blood flow through your heart:
The tricuspid valve regulates blood flow between the right atrium and right ventricle.
The pulmonary valve controls blood flow from the right ventricle into the pulmonary arteries, which carry blood to your lungs to pick up oxygen.
The mitral valve lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle.
The aortic valve opens the way for oxygen-rich blood to pass from the left ventricle into the aorta, your body's largest artery, where it is delivered to the rest of your body.
Electrical impulses from your heart muscle (the myocardium) cause your heart to beat (contract). This electrical signal begins in the sinoatrial (SA) node, located at the top of the right atrium. The SA node is sometimes called the heart's "natural pacemaker." When an electrical impulse is released from this natural pacemaker, it causes the atria to contract. The signal then passes through the atrioventricular (AV) node. The AV node checks the signal and sends it through the muscle fibers of the ventricles, causing them to contract. The SA node sends electrical impulses at a certain rate, but your heart rate may still change depending on physical demands, stress, or hormonal factors.