CH2 Cardiovascular System Flashcards
Circulation
Transporting blood to and from the body
What is recorded on the ECG strip?
Electrical activity of the heart
Pericardium
2 layered sac of tissue enclosing the heart
Endocardium
Inner layer of the heart that lines the chambers and valves.
Myocardium
Middle, thickest muscular layer, responsible for heart contractions
Epicardium
Aka visceral epicardium
Outside, thin layer of the heart that contains the coronary arteries
Inner layer of the pericardium
Interatrial septum
A wall of tissue that separates the left and right atria of the heart
Interventricular septum
A wall that divides the right and left ventricles
List the Semilunar valves
Aortic valve
Pulmonary valve
List the Atrioventricular valves
Tricuspid valve
Bicuspid valve (mitral)
Route of deoxygenated blood to the lungs
Superior and Inferior Vena Cava
Right atrium
Tricuspid Valve (atrioventricular)
Right Ventricle
Pulmonary valve (semilunar)
Pulmonary artery
Lungs
Route of oxygenated blood from lungs to heart to body
Returns through Pulmonary veins
Left atrium
Bicuspid/Mitral Valve(AV Vavle)
Left Ventricle
Aortic valve (semilunar)
Aorta
Body
Pulmonary circulation
Transportation of blood to and from the lungs
Systemic circulations
The pathways for pumping blood to and from the body
Coronary circulation
Thr circulation blood to and from heart muscle
Coronary Circulation pathway
Oxygenated blood in left Ventricle
Aortic Vavle
Aorta
Coronary Arteries (right and left)
Heart
Deoxygenated blood coronary veins
Coronary sinus
Emptied into right atrium
Stroke volume
Volume of blood ejected with each contraction
Estimated cardiac output is calculated by
CO = HR x SV
Cardiac Output = Heart Rate x Stroke Volume
Cardiac Cycle
The contraction and relaxation of the heart
Systole
The contraction phase of the cardiac cycle
Blood pumped to lungs and systemic (body) circulation
Diastole
The relaxation phase of the cardiac cycle where atria expand and refill
True or false:
Each complete lubb-dubb you hear is one beat of the heart
True
What creates the Lubb sound of the heart beat?
Contraction of ventricles
Closing of the AV Valves
- Tricuspid and Bicuspid Valve
What created the dubb sound in the heart beat?
Beginning of the diastolic phase
Closure of the Pulmonary and Aortic valves
Unique qualities that control the beat of the heart and produce the electrical wave?
Automaticity, conductivity, contractility, and excitability/irritability
Automaticity
The ability of the heart to initiate an electrical impulse without being stimulated by an independent source
Conductivity
The ability of the heart cells to recieve and transmit an electrical impulse
Are myocardial cells supposed to conduct electrical impulses?
Yes
Contractility
The ability of the heart muscle cells to shorten in response to an electrical stimulus
Exitabillity/Irritability
The ability of the heart muscle cells to respond to an impulse or stimulus
Heartbeat is controlled by which nervous system
Autonomic Nervous System
ANS
Sympathetic branch of ANS secretes what to increase heart rate and contractility?
Norepinephrine
Parasympathetic branch of ANS secretes what to exert a depressant effect on the heart?
Acetylcholine
What happens when there is a low concentration of potassium ions(hypokalemia)?
Heart rate decreases
What happens if someone has hyperkalemia?
Abnormal heart rate
What happens if somone has hypocalcemia?
Decrease in the force of the heart’s contractions
What happens if someone has hypercalcemia?
Can increase the force of the hearts contractions
Pathway of conduction in the heart
Siniatrial (SA) node
Atrioventricular (AV) Bundle
Right and Left Bundle Branches
- aka. Bundle of His
Purkinje fibers
Pacemaker of the heart aka __
SA Node
Atrial kick
Additional blood that goes into the ventricles before the heart contracts
Inherent rate of SA node
60-100 times per min
Inherent rate of AV Node
40-60 times per min
Interent rate of purkinje fibers
20-40 times per min
Polarization
State of cellular rest in which the inside is negatively charged and the outside is positively charged
Depolarization
The electrical activation if the cells of the heart that initiates contraction of the heart muscle
(Inside becomes positive)
Action potential
The change in the electrical potential of the heart muscle when it is stimulated
Repolarization
The return of heart muscle cells to their resting electrical state, causing the heart muscles to relax
Isoelectric line
The period when the electrical tracing of the ECG is at zero or a straight line, and no positive or negative deflections are seen
Aka. Baseline
P wave
Small curve
Atrial depolarization with resulting atrial contraction
QRS Complex
Ventricular depolarization and resulting ventricular contraction
Atrial repolarization occurs(not seen)
T wave
Ventricular repolarization
U wave
Repolarization of purkinje fibers
- not always seen
- may be seen in instances of Electrolyte imbalance
PR interval
Beginning of atrial depolarization to beginning of ventricular depolarization
QT Interval
Period of time from the start of ventricular depolarization to the end of ventricular depolarization
ST Segment
Time between ventricular depolarization and the beginning of ventricular repolarization
Normal ventricular depolarization time (QRS)
0.06 - 0.12 secs
Ischemia
A sudden loss or reduction in blood supply to a region of the heart tissue
Partial or complete blockage
Normal length of time for PR interval
0.12 - 0.20 secs