Chapter 15 PPT: The Heart Flashcards
HEart Pumps Blood through the blood vessels in what order
Arteries Arterioles Capilalries Venules Veins Back To Heart
Cardiovascular refers to both
heart and blood vessels
Blood vessels form what two circuits
Pulmonary Circuit
Systemic Circuit
What is the Pulmonary Circuit
Transports oxygen-poor blood from heart to lungs and back to heard
Blood picks up O2 in lungs and drops off CO2
What is the Systemic Circuit
Transports oxygen-rich blood from heart to all body cells, and back to heart
Blood delivers nutrients to cells and removes waste
The left side of teh heart contains
oxygen-right blood
The right side of the heart contains
oxygen-poor blood
BLood Runs through 2 Circuits:
Pulmonary Circuit to lungs, and systemic circuit to body cells
Heart is located in the
mediastinum of the thoracic cavity, superior to the diaphragm
Heart contains what 4 chambers
2 Atria (Upper Chambers) 2 Ventricles (Lower Chambers, Pumping Action)
Heart location: Posterior to the
sternum
Heart location: Medial to the
lungs
Heart location: Anterior to the
vertebral column
Heart location: base leis beneath the
2nd rib
Heart location: apex lies at the
5th intercostal space
What is the Pericardium?
Covering over heart and large blood vessels
What is the Fibrious Pericardium
Outer layer, thrat surrounds double-layered serous membrane
What is the Parietal Pericardium?
Deep to fibrious pericardium; outer layer of serous membrane
What is the Visceral Pericardium?
Iner layer of serous membrane
Attached to surface of ehart, also called epicardium
The heart has how many distict layers?
Three
Three layers of the heart?
Epicardium
Myocardium
Endocardium
What is the Epicardium?
Outer layer of heart
Also called Visceral Pericardium
Thin Layer
What is the Myocardium?
Middle layer composted of cardiac mscle tissue
Thickest layer
What is the Endocardium?
Inner layer that forms inner lining of heart chamber’‘Thin Layer
What occurs in the Atria?
Thin-walled upper chambers; receive blood returning to heart
What are the Auricles?
Flap-like projection from Atria, which allow atrial expansio
What are ventricles
Thick-walled lower chambers; pump blood into arteries
What occurs in the right atrium?
Receives blood returning form sysemic circuit (from the superior and inferior vena cavae and coronary sinus) ;
pumps blood to right ventricle
What occurs in the right ventricle
Receives blood from the right atrium, pumps blood to lungs
What occurs in Left Atrium?
Receives blood from pulmonary veins; pumps blood to left ventricle
What occurs in Left Ventricle?
Receives blood form the left atrium; pumps blodo to systemic circuit
Tricuspid Valve Location?
Right antrioventricular Orifice
Tricuspid Valve Function
Prevents blood from moving from the right ventricle into the right atrium during ventricular contraction
Pulmonary Valve Locaiton
Entrance to Pulmonary Trunk
Pulmonary Valve Function
Prevents blood from moving from the pulmonary trunk into the right ventricle during ventricular relaxation
Mitral Valve Location
Left Atrioventricular Orifice
Mitral Valve Function
Prevents blood from moving form the left ventricle into the left atrium during ventricular contraction
Aortic Valve Location
Entrance to Aorta
Aortic Valve Function
Prevents blood from moving from the aorta into the left ventricle during ventricular relaxation
The left and right coronary arteries supply
blood to tissues of the heart
The coronary artieres are first 2 branches of the
aorta
HEart actions are regulated so that
atric contract (atrial systole) while ventricles relax (ventricular diastole)
When ventricles contact (ventricular systole) , the atria
relax (artial diastole)
What is a Left Ventricular Assist Device
Mechanical heart-heart, used in some cases temporarily until donor heart is available
What is a Implantable Replacement Heart
Titanium and plastic artiifal heart, used in people that cannot have heart transplant and do not have long to live
What is a Stem Cell Technology
Cardiac muscle tissue can now be cultured from altered somatic cells or form stem cells. This may allow “stem cell heart patches” in the future
During Artial Systole and Vesticular diastole
Ventricles relaxed
A-V valves opena nd semilunar valves close
70% blood flows from atria to ventricles
Atrial systole pushes remaining 30% of blood into the ventricles
What occurs during ventricular systole and atrial diastole
AV Valves close
Chordae Tendineae prevents back flow
Atria relax
Ventricular pressure increases and opens the semilunar valve
Heart sounds are due to
closing of heart valves and vibrations associated with a suden slowing of blood flow during contraction
What is the lubb sound?
Occurs during ventricular systole
Associated with closing of AV Valves
What is the DUBB sound?
Occurs during ventricular diastole
Associated with closing of pulmonary and aortic semilunar valves
What is a murmur
Abnormal heart sound serived from incomplete closure of cusps of a valve
What is a functional syncytium?
A mass of merging cells that function as a unit
What are the two masses in the heart
In the atrial walls, called atrial syncytium
In the ventricular walls, called the ventricular syncyitium
What is the Cardiac Conduction System?
A group of clumps and strands of specialized cardiac muscle tissue, which initiates and distribute simpulses throughout the myocardium
What is the SA Node?
Pacemaker ; initiates rhythmic contractions of the heart
What is the Internodal Artial Muscle?
Conducts impulses from SA node to atria
What is the Junctional Fibers?
Conduct impulses form SA node to AV node?
What is the AV Node
Conducts impulses to AV bundle; delays impulse, so that atria finish contracting before ventricles contract
What is the AV bundle
COnducts impulses rapidly between SA Node and Bundle branches
What is the LEft and Right Bundle Branches
Split off from AV Bundle, conduct impulses to Purkinje fibers on both sides of heart
Purkinje Fibers, what is it
Large fibers that conduct impulses to ventricular myocardium
When Purkinje fibers stimulate muscle cells,
ventricles contract with twisting motion
What is a ECG?
A recording of electrical changes that occur in the myocardium during the cardiac cycle
What is the P Wave?
Artrial depolarization, occurs just prior to atrial contraction
What is a QRS Complex?
Ventricular depolarization; occur sjust prior to ventricular contraction
What is a T Wave?
Ventricular repolarization; occurs just prior to ventricular relaxation
What normally controls the heart rate
SA Node
Sympathetic and Parasympathetic fibers modify theheart rate in response to changing conditions, such as
Physical Exercise
Body Temperature
Fight or Flight
Concentration of K and Ca
What do Parasympathetic Impulses do?
Via vagus nerve decreases heart rate due to influence on SA and AV Nodes
What do Sympathetic Impulses do?
Via accelerate nerves increase hr due to influence on SA and AV nodes and Ventricular Myocardium
Cardiac control center regulates
autonomic impulses to the heart
What is an Arrhythmias?
Altered heart rhythms
What if Fibrillation?
uncoordinated, chaotic conraction of small areas of myocardium
Atrial fibrillation not life-threatening
What is Tachycardia?
Abnormally fast heartbeat > 100 beats/min
What is Bradycardia?
Abnormally slow heartbeat , <60 beats/min
What is Flutter?
Rapid, regular contraction of a heart chamber, 250-350 beats/min
What is a Premature Beat?
Beat that occurs before expected in normal cardiac cycle; often originates from ectopic regions of heart
What is Ectopic Pacemaker?
Damage to SA node may lead to AV node taking over and acts as secondayr pacemaker , 40-60 /min
What is a Artifical Pacemaker?
Device used to treat disorders of cardiac conduction system; implantable and battery-powered
