Unit 1 Flashcards
Deoxygenated blood enters the ___ by way of
the ____ . Once the atrium is full, ____ occurs
and the blood passes through the ____ into the ___ .
Deoxygenated blood enters the RIGHT ATRIUM by way of the Superior and Inferior Vena Cava. Once the atrium is full contraction occurs and the blood passes through the TRICUSPID VALVE into the RIGHT VENTRICLE
From the right ventricle the blood passes through the _____ into the _____. The blood then passes
into smaller vessels, pick up oxygen and return to the ____ side of the heart by
way of the _____ into the _____ _____
From the right ventricle the blood passes through the PULMONARY SEMI-LUNAR VALVE into the PULMONARY ARTERY. The blood then passes
into smaller vessels, pick up oxygen and return to the **Left **side of the heart by
way of the **PULMONARY VEINS ** into the **LEFT ATRIUM. **
From the LEFT ATRIUM, blood passes though the _____ into the _____ . When the ventricle contracts it opens the ____ and blood passes into the _____.
From the LEFT ATRIUM, blood passes though the MITRAL VALVE into the LEFT VENTRICLE. When the ventricle contracts it opens the **AORTIC SEMILUNAR VALVE **and blood passes into the AORTA.
Label the diagram
- Aorta
- Right atrium
- Right ventricle
- Tricuspid valve
- Pulmonary valve
- Pulmonary artery
- Pulmonary veins
- Left atrium
- Left ventricle
- Superior vena cava
- Inferior vena cava
- Mitral valve
The heart is a __ organ located in the chest, behind the __ within the __. Two thirds of its mass is located to the __ of
the midline of the body. It has __ chambers, __ atria and __ ventricles.
The heart is a muscular fibrous organ located in the chest, behind the sternum within the mediastinum. Two thirds of its mass is located to the ** left** of the midline of the body. It has four chambers, two atria and two ventricles.
Both __ contract at the same time and both __ contract at the same time.
Atria and ventricles
The __ system is a closed system. Coordinated ___ is necessary to provide the body with a fresh
supply of oxygenated blood.
The Cardiovascular system is a **closed **system. Coordinated **contraction **is necessary to provide the body with a fresh supply of oxygenated blood.
What happens when there is a problem with the conduction system?
The muscle does not respond appropriately and blood does not flow effectively through the heart.
How is assessment of the mechanical functions of the heart done?
Measuring pulse, skin color and blood pressure
How is assessment of the electrical function of the heart is done?
Electrocardiogram.
Endocardium
Contains branches of heart’s electrical conduction system
Myocardium
made up of layers and bands of cardiac muscle fibers
Epicardium
single layer of cells supported by connective tissues; contains nerves to heart and coronary blood vessels
A-V Valves
- Tricuspid
- Mitral
Semilunar valves
- Pulmonic
- Aortic
Ventricular systole
Ventricles contract, forcing blood through the pulmonic and aortic valves to lungs and body
Atrial Systole
Atria contract, forcing blood through mitral and tricuspid valces into ventricles
Systolic phase
Contraction
Diastolic phase
Relaxation
What is the purpose of an ecg?
check for signs of heart disease
- Specifically, to diagnose a heart attack or mycardial infarction (MI)
What are indications for a 12-lead EKG?
- Chest pain
- Atypical chest pain
- Epigastric pain (heart burn)
- Back, neck, jaw, or arm pain without chest pain
- Palpitations
- Syncope
- Pulmonary edema
- Extertional dyspnea
V1 Chest lead placement
4th intercostal space to the right of the sternum
V2 Chest lead placement
fourth intercostal space to the left of sternum
V3 Chest lead placement
Directly between leads V2 and V4
V4 Chest lead placement
fifth intercostal space at left midclavicular line
V5 Chest lead placement
Level with V4 at left anterior axillary line
V6 Chest lead placement
Level with V5 at midaxillary line
Current flowing toward a positive electrode creates an __ deflection.
upright deflection.
Current flowing toward a negative electrode creates a ___ deflection.
downward deflection.
Current flowing toward a __ electrode creates a downward deflection.
Negative
Current flowing toward a __ electrode creates an upright deflection.
Positive
isoelectric
Neither upright nor downward
What is a lead?
A combination of electrodes that reflects flow of electricity between two points on opposing sides of the heart.
Polarization
“Ready” state
Depolarization
“Discharge” state
Repolarization
“Recovery” state
Inherent rates of Sinus Node
60-100 BPM
Inherent rates of AV Junction
40-60 BPM
Inherent rates of Ventricles
20-40 BPM
What is the Pacemaker rule?
The Pacemaker site with the fastest rate will generally control the heart
What is irritability?
When a site aling the conduction pathway becomes irritable and speeds up, overriding the higher pacemaking sites for control of the heart
Escape Mechanism
The normal pacemaker slows down or fails, and a lower pacing site assumes pacemaking responsibility
Which layer of the heart wall is this describing?
contains branches of heart’s electrical conduction system
Endocardium
Which layer of the heart wall is this describing?
made up of layers and bands of cardiac muscle fibers
The “work” unit
Myocardium
Which layer of the heart wall is this describing?
single layer of cells supported by connective tissues; contains nerves to heart and coronary blood vessel
Epicardium
What is the cardiac output formula?
CO=HR X SV
What is a normal, healthy cardiac output?
Normally 4 LPM - 8 LPM
EKGs are graphic representations of __ activity within the heart
electrical
Describe polarization
the heart is relaxed and fills with blood. This is the “ready” state
diastole
Describe depolarization
The heart contracts and pushes out blood
systole
Repolarization is also known as the __ state
recovery/refractory
What is the normal pacemaker of the heart?
The AV node
Anything above the isoelectric line is a __
positive inflection
Anything below the isoelectric line is a __
negative deflection
The P wave is shown as what on EKG paper? What does it represent?
Positive inflection
represents atrial contraction / depolarization
What does the QRS complex represent?
Ventricular contraction
What does the T wave represent?
Ventricular repolarization
Positive inflection is when:
When the electrical activity flows towards the __ electrode
Positive
Negative deflection is when:
when electrical activity flows towards the __ electrode
negative
RA
- __ electrode
LA
- “G” - ground
- positive electrode
LL
- ___ electrode
RA
- negative electrode
LA
- “G” - ground
- positive electrode
LL
- positive electrode
RA
- negative electrode
LA
- “G” - ground
- __ electrode
LL
- positive electrode
RA
- negative electrode
LA
- “G” - ground
- positive electrode
LL
- positive electrode
Black hashmarks are __ seconds apart
3 seconds
Large boxes represent __ seconds
.2 seconds
Small boxes represent __ seconds
.04
How many small boxes make up one large box?
5
Voltage is measured by
how high a waveform is on the isoelectric line
Time is measured by
vertical lines
An MI frequently causes __ elevation
ST
ST elevation may indicate a __
Myocardial infarction
What does the PR interval represent?
atrial depolarization and pause through the AV node
starts with atrial contraction - ends with ventricular depolarization
normally .12 - .20 seconds
(3-5 small boxes)
What does the PR segment represent?
delay of the AV node
delay of the AV node is represented by __
PR segment
represents duration of ventricular electrical systole, which includes ventricular depolarization and repolaralization
QT Interval
What does the QT Interval represent?
duration of ventricular electrical systole, which includes ventricular depolarization and repolaralization
Normal QRS is how many seconds?
less than or equal to .12 seconds
How is regularly assessed?
- Regularity pertains to spacing
- count the number of small boxes between R waves
- evenly spaced = regular
- count the number of small boxes between R waves
What do sinus P waves look like?
- dome shaped, uniform and positively deflected
- 1:1 ratio P-wave to QRS
A wide QRS complex may indicate what?
- ventricular pacemaker or supraventricular pacemaker was delayed (bundle branch block)
- depolarization happened slowly
- irritable spot on the ventricle, impulse takes longer
Supraventricular
beats coming from above the ventricles
focus
point of origin
width of the QRS complex can help determine if the rhythm originated from ___ focus or the __
supraventricular focus or the ventricular
