med surg lecture 4 Flashcards
the cardio-vascular system consists of what
-heart
-blood
-vessels
-arteries
-veins
-capillaries
vessels consist of
-arteries
-veins
-capillaries
where is the heart located
central thoracic cavity
Mediastinum
the pericardial sac consists of what
-fibrous pericardium
-parietal pericardium
-visceral pericardium
what is the visceral pericardium also known as
epicardium
what part of the pericardial sac outlines the heart
fibrous pericardium
what part of the pericardial sac is serous membrane and decreases fricton
parietal pericardium
what part of the pericardial sac that is the inner most protective layer
visceral pericardium (epicardium)
what are the cardiac layers
-epicardium
-myocardium
-endocardium
the protective layer of the heart
epicardium
the thick layer of muscle of the heart and aides in contraction
myocardium
the layer of the heart inside the cardiac chambers lining the inside of the heart chambers and valves
endocardium
how the heart is being profused with oxygen is called what
coronary circulation
this artery supplies blood to the right atrium, right ventricle, bottom portion of the left ventricle and back of the septum
right coronary artery
veins that take oxygen-poor deoxygenated blood that has been “used” by muscles of the heart and return it to the right atrium
coronary veins
artery that divides into two branches: the circumflex artery and the left anterior descending artery
left coronary artery
artery that supplies blood to the left atrium and the side and back of the left ventricle
circumflex artery
artery that supplies blood to the front and bottom of the left ventricle and the front of the septum
left anterior descending artery (LAD)
superior chambers of the heart
right atrium
left atrium
inferior chambers of the heart
right ventricle
left ventricle
which part of the heart has the thickest wall
left ventricle
what are the cardiac valves
atrioventricular valves (AV)
semilunar valves
what are the atrioventricular valves
right av valve - tricuspid
left av valve - bicuspid/mitral
coronary blood flow in order
-inferior/superior vena cava
-right atrium
-tricuspid valve
-right ventricle
-pulmonic/pulmonary valve
-pulmonary artery
-lungs (oxygenation occurs)
-pulmonary veins
-left atrium
-mitral/bicuspid valve
-left ventricle
-aortic valve
-aorta
-body tissue/organs
the heart is an _________ driven pump
electrically
the pump is comprised of ______
muscle
the pump requires both ________ and ________ to function
electricity and oxygen
muscle tissue needs _______ to survive
oxygen
electricity is derived from ________
electrolytes
which electrolytes are important for cardiac electrical system
-potassium
-sodium
-calcium
-magnesium
electrical conduction system coordinates both ______ and _______ of the heart chambers
-contraction
-relaxation
pathway of electrical impulses that generates a heartbeat
conduction pathway
electrical impulses causes the heart to _______ and pump _______ to the rest of the body
-contract
-blood
cardiac conduction pathway includes
-sinoatrial (SA) node
-interatrial node/pathway bundle
-atrioventricular (AV) node
-bundle of His
-right and left bundle branches
-purkinje fibers
which node is located in the wall of right atrium
sinoatrial node (SA)
what is also called bachmann’s bundle
interatrial node/pathway/bundle
known as “pacemaker” of the heart
sinoatrial node
this node delays conduction briefly
atrioventricular node
connecting fibers that rapidly send an impulse from the right atrium to the left atrium
interatrial node/pathway/bundle
what starts the heart rate and keeps the heart rate going
sinoatrial node
what gives atria time to contract and pump all blood into the ventricles
atrioventricular node because it delays conduction briefly
conduction passes from av node and travels through
bundle of his
conduction bifurcates into the what and travels through the walls of venticles
right and left bundle branches
fibers spread widely across the ventricles to cause all cells of the ventricles to contract quickly and this is when blood is expelled from ventricles
purkinjie fibers
as atria and ventricles refill with blood the SA and AV node _______ with electrolytes so that they can repeat the electrical conduction cycle again
recharge
cardiac conduction pathway in order
-sinoatrial node
-interatrial node/pathway/bundle (bachmanns bundle)
-atrioventricular node
-bundle of his
-right and left bundle branches
-purkinje fibers
a single cycle of cardiac activity can be divided into what two phases
systole
diastole
contraction of chambers is called what
systole
relaxation of chambers is called what
diastole
atrial systole
atria contracts, blood flows from the atria into ventricals
ventricular diastole
ventricles relax filling with blood sent from atria
amount of blood ejected from the left ventricle in one minute
cardiac output
how do you calculate cardiac output
stroke volume x heart rate
amount of blood pumped per beat
stroke volume
number of heart beats in one minute
heart rate
what is cardiac output measured in
L/min or mL/min
what is the average cardiac output for a healthy adult is about
5L/min
amount of blood the left ventricle pumps out with each contraction
ejection fracture
what value shows how well the heart is functioning
the ejection fraction value
normal range of ejection fraction
55% - 70%
an ejection fraction under 40% may be evidence of _________ or _________
heart failure or cardiomyopathy
what is the most common test performed to determine the ejection fraction
echocardiogram
force of blood against blood vessel walls
blood pressure
what is blood pressure measured in
millimeters of mercury
why is blood pressure greatest in the arteries
there is more force to get to the body
arteries and arterioles are usually slightly _______ to maintain normal blood pressure
constricted
if heart rate and force of contraction increases what happens
blood pressure increases
if heart rate is increased but ventricles are not filing prior to contraction, cardiac output will be decreased and cause blood pressure to what
decrease
the average pressure within the arteries throughout one cardiac cycle (systole and diastole)
mean arterial pressure
what is considered a better indicator of perfusion to vital organs than the blood pressure
The MAP
if the MAP is below __ mmHg for prolonged periods of time, vital organs are not receiving adequate blood flow and oxygen
65
if the MAP is above ___ mmHg for prolonged periods of time the heart workload is increased which leads to various complications
100
what is the MAP equation
systolic blood pressure + 2 times the diastolic blood pressure divided by 3
what does MAP stand for
mean arterial pressure
when calculating the MAP if results are decimals what do you need to do
round to the nearest whole number
hormones made by your adrenal glands
catecholamines
neurotransmitters of the sympathetic nervous system
epinephrine and norepinephrine
what happens when epinephrine and norepinephrine are released
-increased impulse conduction
-increased heart rate
-increase in systolic BP (due to increased cardiac output)
what regulates serum sodium and potassium levels
aldosterone