Cardiovascular System Flashcards
Anatomy of heart
apex base located in the thoracic cavity between the 2 pleural cavities
directed toward the left hip and rests on the diaphragm
apex
larger, flat end at the posterosuperior aspect, directed towards the right shoulder where the great vessels emerge
base
median partition formed by the heart, trachea, esophagus and associated structures
mediastinum
Coverings of heart
pericardium
double sac of serous membrane that encloses the heart
pericardium
2 layers of pericardium
parietal pericardium visceral pericardium or epicardium
outer fibrous layer that protects the heart and anchors it to the surrounding structures such as the diaphragm and sternum
parietal pericardium
tightly hugs the external surface of the heart and is actually part of the heart wall
visceral pericardium
other name of visceral pericardium
epicardium
space between the parietal and visceral pericardia
pericardial cavity
reduces friction between layers of serous pericardium
pericardial fluid
3 layers of the heart wall
epicardium myocardium endocardium
outer layer
epicardium
middle layer consists of thick bundles of cardiac muscle layer that contracts
myocardium
innermost layer thin glistening sheet of endothelium that lines the heart chambers
endocardium
4 hollow chambers or cavities
atria ventricles
located superiorly receiving chambers
atria
separates 2 atria
interatrial septum
located inferiorly thick-walled discharging chambers
ventricles
separates 2 ventricles
interventricular septum
great vessels
superior vena cava ingerior vena cava pulmonary trunk pulmonary veins aorta
returns oxygen-poor blood from veins of the upper part of the body to right atrium
superior vena cava
returns oxygen-poor blood from veins of lower part of body to right atrium
inferior vena cava
splits into right and left pulmonary arteries carries oxygen-poor blood to the lungs for oxygenation
pulmonary trunk
carries oxygenated blood from lungs to left atrium
pulmonary veins (4)
where systemic arteries branch out to supply blood to body tissues
aorta
circulation from the right side of the heart to the lungs and back to the left side of the heart
pulmonary circulation
function of pulmonary circulation
carry blood to the lungs for gas exchange and then return it to the heart
circulation from the left side of the heart through the body tissues and back to the hear
systemic circulation
allows blood to flow in only 1 direction through the heart chambers
heart valves (4)
heart valves
atrioventricular valves (AV valves) semilunar valves
between atria and ventricles prevent backflow of blood back into atria when ventricles contract
atrioventricular valves
AV valves
tricuspid valve bicuspid or mitral valve
left AV valve
bicuspid valve
right AV valve
tricuspid valve
AV valves ______ during systole and ______ during diastole
close open
guards the bases of the 2 large arteries leaving the ventricles
semilunar valves
semilunar valves
pulmonary valve aortic valve
prevent backflow of blood into R ventricle
pulmonary or pulmonic valve
prevent backflow of blood into L ventricle
aortic valve
semilunar valves ________ during systole and ______ during diastole
open close
Conduction System of Heart
SA node AV node AV bundle/Bundle of His left and right Bundles Purkinje Fibers
pacemaker of heart superior wall of R atrium produces AP at higher rate than other parts of heart
initiates impulses
SA node/ Sinoatrial node
SA node produces
80-100 beats/ min
Lower portion of right atrium AP spread slowly through it delays to allow atria to finish contracting
AV node/Atrioventricular node
projects through the interventricular Septum then divides into 2 branches of conducting tissues called the R & L bundle brances
Bundle of His/ Atrioventricular bundle
spread within muscles of ventricles
Purkinje fibers
Functions of Cardiovascular System
Generating blood pressure Routing blood Ensuring one-way blood flow Regulating blood supply
a recording that traces the flow of electrical current or events through the heart
Electrocardiogram
depolarization of atria beginning of this precedes the onset of atrial contraction
P wave
depolarization of ventricles beggining precedes ventricular contraction
QRS Complex
repolarization of ventricles
T wave
atria contract and begin to relax; at the end ventricles begin to contract
PQ/PR Interval
ventricular repolarization and depolarization
QT Interval
repetitive pumping process begins with the onset of cardiac muscle contraction and ends with beginning next contraction pressure changes produced by heart chambers due to contraction propels blood movement; higher pressure to lower pressure
cardiac cycle
2 distinct sounds during each cardiac cycle; heard using stethoscope
heart sounds
S1 lower pitch closure of AV valve at beginning of systole longer and louder
lubb
S2 higher pitch caused by closure of semilunar valve at end of systole short and sharp
dupp
abnormal heart sounds caused by faulty valves that fail to close tightly blood leaks swishing sound
murmurs
volume of blood pumped by either ventricle each minute
cardiac output
cardiac output =
stroke volume x HR
volume of blood pumped out by a ventricle with each heartbeat increases as force of ventricular contraction increases
stroke volume
normal HR under resting condition
72-75 beats/min
SV
70 ml/beat
CO =
5040-5250 ml/min
the volume of blood in the left ventricle at the end of diastole, just before systole
end diastolic volume
end diastolic volume
130 ml
volume of blood in the ventricles just after systole
end systolic volume
end systolic volume
50 ml of blood ejection fraction about 65%
types of blood vessels
arteries arterioles capillaries venules veins
carries blood away from heart
arteries
very small arteries that carry blood to capillaries
arterioles
carries blood to heart
veins
tunics of arteries / veins
tunica interna/ tunica intima (artery) tunica media tunica externa
contains lining of simple squamous epith. called endothelium
tunica interna/tunica intima of artery
microscopic vessels that connect arterioles to venules
capillaries
veins formed by union of several capillaries
venules
inner layer is thinner than arteries
tunica interna of vein
middle layer and thickes layer consists of elastic fibers and smooth muscle fiber cells that extend circularly the lumen
tunica media of artery
thinner than arteries with little smooth muscle and elastic fibers
tunica media of vein
outer layer and composed mainly of elastic and collagen fibers
tunica externa of artery
thickest layer and consists of collagen and elastic fibers
tunica externa of veins
has lamina
artery
more deep into skin
artery
no presence of valves
artery