Chapter 20 - Cardiovascular system Flashcards
what is the estimated length of the blood vessels in our body?
75,000 miles of blood vessels
where is the heart located?
In between th lungs in the mediastinum, with 2/3 of mass to the left of midline
How big is the heart?
size of your closed fist
What are the 7 surfaces of the heart?
right, left, inferior, anterior, posterior, apex, and base
Apex= bottom
Base=top
fill the blank: the heart is enclosed and held in place by the _______________
preicardium
what are the 2 layers of pericardium? what layer surface are they?
viceral=the inner layer, on top of the heart
Parietal=surface layer
def: pericarditis
Inflammation of the pericardium
name the 3 layers of the heart wall from farthest to closest
- Epicardium:outer
- Myocardium: middle
- Endocardium: inner
describe the 3 layers of heart: epicardium, Myocardium, Endocardium
Epicardium
visceral layer of serous pericardium
adheres to surface of heart
mesothelium and connective tissue
Myocardium
cardiac muscle layer
responsible for pumping
Endocardium
inner endothelial lining
covers chambers and valves
reduces surface friction
endothelium and connective tissue
def: Myocarditis
inflammation of the myocardium;
usually a complication of a viral infection
def: Pericarditis
often linked to viral infection;
inflammation of the pericardium; acute of chronic
Def: Endocarditis
inflammation of endocardium;
involves heart valves; often bacterial; associated
with heart murmur
Def: Pericardial friction rub
scratchy sound;
rubbing of visceral and parietal layers of the
pericardium
What are auricles? they are on the surface of heart
they are small pouches on the anterior surfaces of each atrium, which allow them to have higher capacity of blood
What are sulci?
they are gtooves that contain blood vessels and fat, and seperate the chambers
What are the 3 sulci located on the heart called?
- Coronary sulcus
- Anterior interventricular sulcus
- Posterior interventricular sulcus
name the four chambers of the heart. which are on top and which are on bottom
right left atria, right left ventricles
atria on top, ventricles on bottom
explain the function of the right atrium
receives blood from superior and inferior vena cava, and the coronary sinus
what valve does the blood pass through, from the right atrium into the right ventricle?
the Tricuspid valve
Explain the function of the right ventricle?
it receives blood from right atrium and sends it to the lungs un oxygenated
3 tendon types that hold the ventricles from the inside together, and help with stability. what are they called?
Trabecular carneae: series of ridges
formed by raised bundles of cardiac
muscle fibers in the ventricles
Chordae tendineae: tendon-like cords
between the papillary muscles and cusps
of the tricuspid valve
Papillary muscle: cone-shaped
trabeculae carneae connected to the
chordae tendineae
Explain function of the left atrium
it receives blood from the pulmonary veins, it then passes into the left ventricle
what valve allows blood to pass from the left atrium to the let ventricle?
Bicuspid valve
Explain function of the left ventricle.
receives blood from left atrium and then sends it all over the body
TorF: the wall of the left ventricle is much thicker than the right ventricle
True
What valve allows the blood to pass from the left ventricle to the ascending aorta?
Aortic valve(aortic semilunar valve)
What is the fibrous skeleton?
It forms the foundation to which the heart valves attach. prevents over-stretching, acts as an electrical insulator
What do the right and left atrioventricular valves do?
prevent backflow from the ventricles into the atria
what do the right and left semilunar valves do?
prevent backflow from the arteries to the ventricles
fill the blank: a narrowing of a heart valve opening that restricts blood flow is kown as ________
stenosis
Fill the blank: Failure of a valve to close completely is termed __________________
insufficient
What disease can damage or destroy heart valves?
Rheumatic Fever
Def: Ventricles contract
semilunar valves open when pressure in the ventricles exceed the pressure in the arteries
Def: Ventricles relax
blood starts to flow back toward the heart and fills the valves cusps, which causes the valve to close tightly
Whats a good way to remember what side of the heart pumps to wich part of the body?
Right to Respiratory
Left to Limbs
What us Coronary Circulation:
it is the flow of blood that pierces the myocardium and is able to deliveer oxygen to this layer
the 2 types of coronary’s are…
Coronary arterys and coronary veins
Def: Angina Pectoris
Chest pain from ischemia
Def: Myocardial infraction(Heart attack)
death of tissue due to lack of blood supply
What is it called when cardiac muscle cells are self-excitable?
Autorhythmic
What do autorhythmic cardiac muscle cells act as?
they are pacemakers that set a rhythm for entire heart. they form the conduction system, creating the action potentials in the heart
Name the components of the Conduction System(5 of them)
- Sinoatrial(SA) node: pacemaker
- Atrioventricular bundle(bundle of His)
- Right and left bundle branches
- the subendocardial conducting network(Purkinje fibers)
name the order of electrical signal through the components
SA - AV - AV bundle - right/left bundle branches - Purkinje fibers
What are the 3 parts of action potential in a contractile fiber
Rapid depolarization, Plateau, repolarization
what does EKG or ECG stand for?
electrocardiogram
What doe EKG help us with?
helps determine if the conduction pathways are abnormal, is heart is too big, and if certain regions are damaged
What are the 3 parts that EKG has
P wave: atrial depolarization, spread of impulse
from SA node over atria
QRS complex: ventricular depolarization, spread of impulse through ventricles
T wave: ventricular repolarization
What does one cardiac cycle consist of
A contraction(systole) and relaxation(diastole)
What is the Systole?
Contraction, blood leaves the ventricles
What is the Diastole?
relaxation. ventricles fill
What is it called when we listen to sounds within the body? what do we use?
Auscultaion
Stethoscope
What are the 2 haert sounds called? what does each sound represent?
there is “S1, lubb” and “S2, dupp”
S1 is created from the blood turbulence associated with the closing of the atrioventricular valves, soon after the ventricular system began
S2 is the closing of the semilunar valves happening around the end of the ventricular systole
The first sound is louder/longer
what is a heart murmur?
abnormal clicking, rushing or gurgling sound. These are caused by abnormal anatomy or increased volume of flow
Explain Isovolumetric relaxation
It is the occurence when all 4 valves are closed, and the ventricular blood vloume does not change
What is the Cardiac output in a resting adult male? how much higher can it go during exercise?
5 L/min
up to 19 L/min
Define what is cardiac output?
the volume of blood ejected from the left ventricle, ino the aorta each minute
Define what is Stroke Volume?
The ammount of blood ejected from the left ventricle with each contraction
What is the formula to find Cardiac output?
CO = SV x HR
What are the 3 factors that regulate stroke volume, and what do each one do.
- Preload: the degree of stretch on the heart before it contracts
- Contractility: the forcefulness of
contraction of individual ventricular muscle fibers - Afterload: the pressure that must be
exceeded if ejection of blood from the
ventricles is to occur
What is the Frank-Starling Law of the heart
it is, that the greater the filling of the heart ventricles, will result in a greater force of contraction
almost like a sling shot
What are the 6 factors that affect heart rate
Autonomic Nervous system
Chemical regulation
Age
Gender
Physical fitness
temperature
What are the 3 things that need to occur, in order for stroke volume to increase?
Increased Preload
Increased Contractility
Decreased Afterload
What is Coronary artery disease (CAD)
when the heart does not receive enough blood due to obstruction, usually from a accumulation of “atherosclerotic plaques” in arteries
What is Atherosclerotic plaques
thickening of the walls of arteries and loss of elasticity
What is arythmyia/disrythmyia
abnormal rhythm as a result of a defect in the conduction system of the heart
Bradycardia: too slow
Supraventricular tachycardia: fast but regular heart beat
Atrial flutter: rapid regular atrial contractions
