Cardiovascular System - Heart Flashcards
Exam 1
Heart
muscular pump
4 chambers of the heart
right atrium, right ventricle, left atrium, left ventricle
List the Coverings of the Heart
Fibrous pericardium
Parietal layer of serous pericardium
Pericardial cavity
Epicardium (visceral layer of serous pericardium)
Myocardium
Endocardium
Cardiac Cycle
a cycle of contraction and relaxation of the heart
Where do arteries carry blood?
away from the heart
Where do veins carry blood?
into the heart
What are the 2 major valve types of the heart?
atrioventricular; semi-lunar
Name the atrioventricular valves and where are they located?
tricuspid valve: between right atrium and right ventricle
bicuspid (mitral) valve: between left atrium and left ventricle
Name the semilunar valves and where are they located?
pulmonary semi-lunar valve: between right ventricle and pulmonary artery
aortic semi-lunar valve: between left ventricle and aorta
What empties blood into the right atrium?
Explain from where the blood comes for each answer
superior vena cava: returns blood from body regions above diaphragm
inferior vena cava: returns blood from body regions below diaphragm
coronary sinus: returns blood from coronary veins (the wall of the heart)
Which side of the heart carries deoxygenated blood?
right side
Which side of the heart carries oxygenated blood?
left side
What type of blood do arteries carry?
oxygenated blood, except for pulmonary artery
What type of blood do veins carry?
deoxygenated blood, except for pulmonary vein
What are the three parts of the aorta?
ascending aorta, aortic arch, descending aorta
What are the components of the heart wall?
What type of tissue is each layer composed of?
endocardium (simple squamous epithelium AKA endothelium)
myocardium (cardiac muscle, myocytes)
epicardium (connective tissue; AKA visceral pericardium)
What muscle is responsible for heart contractions and relaxation?
myocardium
4 types of tissue
epithelial; connective; muscle; nervous
What are 2 other terms for heart contraction?
systole and depolarization (filling)
What are 2 other terms for heart relaxation?
diastole and repolarization (releasing)
What causes heart depolarization?
What ion movement occurs during depolarization?
an electrical nervous action potential (impulse); sodium moves in and potassium moves out
What acts as the heart’s backup system?
sympathetic and parasympathetic pathway
Name the contractile cells
sinoatrial (SA) node and atrioventricular (AV) node
- make up 99% of heart cells
Sinoatrial (SA) node
And where is it specifically located?
AKA heart pacemaker; begins the heart contraction through the wall of right and left atria; located where superior vena cava empties into the right atrium
Atrioventricular (AV) node
where right atrium meets right ventricle; receives blood from SA node
Conduction System
initiates and coordinates heartbeat
Name the Conductive Cells
bundle of HIS; bundle branches; Purkinje fibers
- make up 1% of heart cells
Bundle of HIS
AKA interventricular bundle; located in interventricular septum; receives blood from AV node
Bundle branches
bundle of HIS splits into right and left bundle branches
Purkinje Fibers
each bundle branch enters into ventricular cardiac muscles forming Purkinje fibers
What are the 3 main stages of ECG (EKG) Pathway?
Explain heart function at each stage
- P wave: atrial depolarization (systole)
- QRS complex: ventricular depolarization (systole) and atrial repolarization (diastole)
- QT interval: the time ventricles depolarize until they have finished repolarizing
- ST segment: ventricular systole
- T wave: ventricular repolarization (diastole)
3 Main Factors That Affect Stroke Volume
preload, contractility, afterload
Preload
degree to which cardiac muscle cells are stretched just before they contract
Contractility
contractile strength at given muscle length; muscle cells ability to move by shortening; increased contractility lowers End Systolic Volume (ESV)
Afterload
pressure that ventricles must overcome to eject blood
Trabeculae Carnae
irregular ridges of muscle on ventricular walls
Chordae Tendinae
anchor AV valves to papillary muscles; keeps valve flaps closed to prevent backflow
Foramen Ovale
small hole of muscular tissue between left and right atrium, allowing blood to cross atria and bypass pulmonary circulation during fetal development
Fossa Ovalis and its function
remnants of foramen ovale of fetal heart; located in interatrial septum; prevents blood flow, blocking circulation of blood across interatrial septum
Intercalated discs
wire that reaches to all heart muscle to allow contraction; desmosomes junction to hold cells together
Pericarditis
inflammation of the pericardium, causing pericardial friction rub and cardiac tamponade
Atherosclerosis
plaque build up blocking blood flow through arteries
Hemorrhoids
elevated venous pressure. Can be caused by straining to deliver baby or have bowel movements
Valvular Stenosis
stiff valve flaps that constrict opening; requires heart to exert more force to pump blood
Incompetent Valve
blood backflows, so heart repumps same blood over and over
Pathway of Blood Through Right Side of Heart
Vena cavas and coronary sinus -> Right atrium -> Tricuspid valve -> Right ventricle -> Pulmonary semilunar valve -> Pulmonary trunk -> Pulmonary arteries -> Lungs (pulmonary circulation)
Pathway of Blood Through Left Side of Heart
Four pulmonary veins -> Left atrium -> Mitral valve -> Left ventricle -> aortic semilunar valve -> aorta -> Body (systemic circulation)
Which ventricle’s wall is thicker?
Left (3x thicker); pumps greater pressure, but same volume of blood as right ventricle
Pulmonary Trunk
- receives blood from right ventricle
- splits into two pulmonary arteries
- sends blood to lungs
Pulmonary Veins
- 4 of them return oxygenated blood to left atrium
Ascending Aorta
gives off two coronary arteries to supply blood to heart wall
Arch of the Aorta
gives three branches that supply blood to the shoulders, arms, head, and neck
Descending Aorta
extends inferiorly to supply blood to the structures present in the thoracic, abdominopelvic cavities, and legs
Angina Pectoris
thoracic pain caused by lack of blood delivery to myocardium
Myocardial Infarction
heart attack; prolonged coronary blockage
What is the foramen ovale?
muscular tissue btwn left and right atrium, allowing blood to cross atria and bypass pulmonary circulation during fetal development
What is used to reduce the friction between membranes surrounding of the heart?
pericardial fluid
In a fetus, which structure temporarily shunts blood from the pulmonary trunk into the aorta?
ductus arteriosus
As each ventricle contracts where does blood move?
through the designated arteries
As each atrium contracts where does blood move
to the designated ventricles
In which disorder is the aortic valve narrowed?
aortic stenosis
Which valves of the heart does not have chordae tendineae attached?
semilunar valves
Which period of the cardiac cycle represents greatest cardiac output?
ventricular systole
Which part of the brain regulates heart rate?
medulla oblongata
The second heart beat sound is represented by what?
closure of semilunar valves
Stimulation of which nerve reduces heart rate?
vagus nerve
What is the volume of blood ejected from the left ventricle into the aorta each minute?
more than 5,000 mL of blood per minute
What’s indicative of an ECG (EKG) lacking a P wave?
atrial fibrillation; no atrial depolarization
What are the risk factors for cardiovascular disease?
high blood pressure, obesity, unhealthy diet
What are the small muscle masses attached to the chordae tendineae in the endocardium of the heart?
papillary muscle
What causes heart sounds?
blood flowing through heart chambers as the cardiac valves open and close during cardiac cycle
What causes heartbeat sounds?
closing of AV and SL valves
What is cardiac output?
amount of blood pumped out by each ventricle in 1 minute; determined by heart rate x stroke volume
What factors will increase cardiac output?
increased heart rate, increased preload, increased myocardial contractility, decreased afterload
What is Fossa ovalis and its function?
a depressed structure that’s located in the interatrial septum; prevents blood flow, blocking the circulation of blood across interatrial septum
Which structures act as anchors for the atrioventricular valves?
chordinae tendinae
The internal lining of the cardiovascular system is formed by what tissue?
endothelium
If a patient received trauma to the chest that caused severe impairment of the primary pacemaker cells of the heart, which area received the greatest damage?
right atrium; SA node
Where is the primary cardiovascular control center in the brain?
medulla oblongata
What is the layer that protects the heart?
epicardium
Which layer of the heart consists of inelastic dense irregular connective tissue?
fibrous pericardium
What layer of the heart consists of mesothelium and connective tissue?
epicardium
What marked the boundary between the ventricles?
interventricular septum (sulci)
What is the equivalent of trabeculae carneae in atria?
pectinate muscles
What types of tissue comprise the valves of the heart?
dense irregular connective tissue
Which of the valves prevents blood from flowing back from the lungs?
pulmonary valve
What vessel distributes oxygenated blood to the myocardium?
coronary artery
What electrically connects cardiac muscle to neighboring fibers?
gap junction (demosomes)
What muscle type contains the largest amount of mitochondria?
cardiac muscle
A network of specialized cardiac muscle fibers that provide a path for each cycle of cardiac excitation to progress through the heart
conduction system
By comparison, cardiac muscle cells have ____ contraction plateau time than skeletal muscle cells.
a longer
The period of time during a cardiac cycle when contraction occurs and blood pressure rises
systole
Which part of the heart can initiate a contraction and can set a constant heart rate of about 100 beats per minute?
SA node
Which electrical event represents repolarization of the ventricle?
T wave
Auscultation
listening to the sounds of the body
