Cardiovascular Flashcards
where is the heart located?
mediastinum
what direction does the heart point in?
apex (inferior to the left)
base (posterior to the right)
what is the pericardium?
the membrane that surrounds and protects the heart
confines the heart to its position in the mediastinum to allow rapid movements or vigorous movements
what is the rile of the fibrous pericardium?
prevents overstretching of the heart and anchors it tp the mediastinum
what is the role of the serous pericardium?
contains pericardial fluid which lubricates the layers of the heart to prevent frictioning
what are the layers of the heart wall?
epicardium (contains adipose tissue)
myocardium (muscle layer making up 95%)
endocardium (covers valves of the heart and continues to cover large blood vessels)
what are auricles?
a wrinkled pouch-like structure that holds great volumes of blood
what are sulci?
grooves found in the heart
what are the coronary sulcus?
encircles most of the heart
what are the three major veins that supply the heart with blood?
superior vena cava
inferior vena cava
coronary sinus
where would you find pectinate muscles?
inside the anterior wall of the right atrium creating a rough muscular surface
what is the difference between the interatribal and interventricular septum?
interartiral (between the atriums)
interventricular (between the ventricles)
what is the difference between the tricuspid and bicuspid valves?
tricuspid (found between the right atrium and ventricle)
bicuspid (found between the left atrium and ventricle)
what are the chordae tendineas?
bundles of cardiac muscle fibers that act as strings to help open and close valves
connected to the papillary muscles
what is the pulmonary valve?
found between the right ventricle and the pulmonary trunk. delivers deoxygenated blood to the lungs to become oxygenated
what is another name for the bicuspid valve?
mitral or left atrioventricular valve
where does blood flow from when leaving the left ventricle?
to the aortic valve then ascending to the aorta. blood then can either flow to coronary arteries which lead to the heart wall or to the arch of the aorta
what is the ductus arteriosus?
temporary blood vessel present at fetal growth which allows only a small amount of blood to enter the fetal lungs to prevent excess fluid in the lungs
what is the ligamentum arteriosum?
the later outcome of the ductus arteriosus which connects the arch of the aorta to the pulmonary trunk
what is the role of the fibrous skeleton of the heart?
prevents overstretching of the chambers and also act as an insulator
what is the difference between the atrioventricular valve and the semilunar valve?
atrioventricular valve (found between the atrium and the ventricles)
semilunar valve (found between the ventricles and the aorta or pulmonary trunk)
what are intercalated disc?
irregular transverse thickening of the sarcolemma connecting ends of cardiac muscles together
what are desmosomes?
found in the intercalated disc
hold fibers together
what are gao junctions?
allow muscles action potentials to conduct from one muscles to the next
what is the autorhythmic fibers?
self-excitable fibres that are the source of electrical activity
what are the main functions of the autorhythmic fibres?
pacemaker
cardiac conduction system
where does cardiac action potential begin?
in the SA nodes or sinoatrial node
what is the order of action potential of cardiac fibres?
SA nodes
AV nodes
bundle of HIS
right and left bundle branches
Purkinje fibres
where does delay of action potential occur?
at the AV nodes to allow the blood to empty the ventricles
what chemical is responsible for depolarization?
Na
what chemical is responsible for plateau?
Ca+
what chemical is responsible for depolarization?
K
what is the role of an electrocardiogram machine?
records action potentials produced by all the heart muscle fibers during each beat
what does the P wave represent?
atrial depolarization
what does the GRS complex represent?
ventricular depolarization
what does the T wave represent?
ventricular repolarization
why can’t we see the atrial repolarization on an ECG machine?
since ventricular contraction is stronger than artial relaxation (occur at the same time)
what is the cardiac cycle?
events of one heart beat
what is the end-diastolic volume?
amount of blood in the ventricle at full relaxation (130 mL)
what is the isovolumetric contraction?
when both valves are closed for 0.05 second at the end of ventricular contraction
what is the end-systolic volume?
amount of blood remaining in the ventricle after relaxation ( 70 mL )
what is ausculatation?
act of listening to the sounds of the body
describe the “lubb dubb” sound of the heart
lubb (longest sound caused by valves closed at ventricular systolic)
dubb (shorter sound causes by valves shutting when ventricles is relaxed)
what is stroke volume?
amount of blood ejected by the ventricle during contraction
what is cardiac output?
the volume of blood ejected from the left ventricle into to aorta each minute
how do you calculate cardiac output?
stroke volume x heart rate
what is cardiac resevre?
difference between a persons maximum cardiac output and rest
what is the frank starling law?
more the heart fills with blood during diastole, the greater the force of contraction
what is systemic circulation?
all arteries and arterioles that carry oxygenated blood from the left ventricle to systemic capillaries (body circulation)
what is pulmonary circulation?
blood returned to the heart from the systemic route
What is coronary circulation?
supplies the heart wall with blood since the nutrients are not able to diffuse quickly enough from blood in the chambers of the heart to supply each layer of the heart wall
where does the right coronary arise from? what does is supply?
arise (ascending aorta)
supply (small branches of right atrium)
where does the left coronary artery arise?
arise (ascending aorta)
where does the anterior interventricular branch arise? where does it supply?
arise (left coronary artery)
supplies (both ventricle walls)
where does the circumflex branch arise? where does it supply?
arise (left coronary artery)
supplies (left ventricle and left atrium)
where does the posterior inter ventricular branch arise? where does it supply?
arise (right coronary artery)
supplies (wall of both ventricle)
where does the marginal branch arise? where does it supply?
arise (right coronary artery)
supplies (right ventricle myocardium)
what is the role of the coronary sinus?
remove deoxygenated blood from the heart and empties the right atrium
what is the role of the great cardiac vein?
removes deoxygenated blood from the left and right ventricle and left atrium
what is the role of the middle cardiac vein
removes deoxygenated blood from the ventricles (both)
what does the small cardiac vein do?
removes deoxygenated blood from the right atrium and ventricle
what is the role of the anterior cardiac vein?
remove deoxygenated blood from the right ventricle and opens it to he right atrium
what is anastomoses?
two or more arteries are connected and supply the same region
where do the following aortas arise?
ascending
aortic arch
thoracic
abdominal
ascending (left ventricle to the pulmonary trunk)
aortic arch (T4-T5)
thoracic (before the diaphragm at T12)
abdominal (after the diaphragm at T12 to L4)
what are the three divisions of the arch?
brachiocephalic trunk
left common carotid artery
left subclavian artery
what is the main vein of the heart?
coronary sinus
where does the superior vena cava drain blood from?
head, neck, upper limbs, thorax