Cardiovascular System
Action potential in cardiac muscle - the resting membrane potential of cardiac muscle is -___ mv, similar to that of skeletal muscle. The AP on a cardiac muscle cell lasts from ___-____ ms, thirty times as long as one on skeletal muscle.
Action potential in cardiac muscle - the resting membrane potential of cardiac muscle is -90 mv, similar to that of skeletal muscle. The AP on a cardiac muscle cell lasts from 250-300 ms, thirty times as long as one on skeletal muscle.
______________ - this represents the amount of force the ventricle must develop to force open the semilunar valves.
Afterload - this represents the amount of force the ventricle must develop to force open the semilunar valves.
____ __ _____ _________ - heart contracts with max force with each contraction with every AP cycle.
All or none response - heart contracts with max force with each contraction with every AP cycle.
_________ ___ (preload) - must do so by altering the venous return, which is the amount of blood returning to the heart. Increasing EDV stretches the cardiac muscle fibers.
Altering EDV (preload) - must do so by altering the venous return, which is the amount of blood returning to the heart. Increasing EDV stretches the cardiac muscle fibers.
Altering ESV ____________ - This is the amount of force produced during a contraction independent of the preload. Under most circumstances, ______________ is the most important factor in altering ESV and therefore stroke volume or how much it will contract.
Altering ESV (contractility and afterload) - Contractility - This is the amount of force produced during a contraction independent of the preload. Under most circumstances, contractility is the most important factor in altering ESV and therefore stroke volume or how much it will contract.
An average value for a resting heart would be -__ BPM X __ ml = 4900 ml or about 5 liters per minute
An average value for a resting heart would be - 70 BPM X 70 ml = 4900 ml or about 5 liters per minute
Anatomy of the heart - Dual pump, __ sides, left and right. 2 distinct circulatory pathways: _________ pathway and __________ pathway.
Anatomy of the heart - Dual pump, 2 sides, left and right. 2 distinct circulatory pathways: systemic pathway and pulmonary pathway.
Angina pectoris - usually chest pain, migrates to ______ arm and usually due to blockage of one or more coronary arteries.
Angina pectoris - usually chest pain, migrates to left arm and usually due to blockage of one or more coronary arteries
Atrioventricular valves (2) - regulate blood flow from ______ to ventricles.
Atrioventricular valves (2) - regulate blood flow from atria to ventricles
Bicuspid (mitral) - between ____ atria and ____ ventricle. Made up of 2 flaps
Bicuspid (mitral) - between left atria and left ventricle. Made up of 2 flaps
________ ________ - difference between cardiac output at rest and maximum cardiac output.
Cardiac reserve - difference between cardiac output at rest and maximum cardiac output.
Cellular organization - cardiac muscles are made up of branching __________ cells. Separated from one another by __________ _______. Have 2 types of membrane junctions, ________ (fasten it together), and ___ _________ (permit movement of ions, AP).
Cellular organization - cardiac muscles are made up of branching striated cells. Separated from one another by intercalated disks. Have 2 types of membrane junctions, desmosomes (fasten it together), and gap junctions (permit movement of ions, AP).
Conduction - depolarization wave spreads from __ node to the _________ of the atrium. Just above the ventricles there is an _____ ____________ valve, depolarization wave will now pass through this toward ventricles.
Conduction - depolarization wave spreads from SA node to the myocardium of the atrium. Just above the ventricles there is an atrial ventricular valve, depolarization wave will now pass through this toward ventricles.
Congestive heart failure - pump is __________, no longer pumping all of the blood it receives resulting in __________ of blood. Usually in one side or the other.
Congestive heart failure - pump is failing, no longer pumping all of the blood it receives resulting in pooling of blood. Usually in one side or the other.
Control of stroke volume - stroke volume is equal to end __________ volume (EDV) or the amount of blood in the ____________ at the end of ________, minus the end ________ volume (ESV) or the amount of blood left in the ventricles following __________ [SV = EDV - ESV]. For example, if EDV is 120 ml and ESV is 50 ml then SV will be equal to 70 ml.
Control of stroke volume - stroke volume is equal to end diastolic volume (EDV) or the amount of blood in the ventricle at the end of diastole, minus the end systolic volume (ESV) or the amount of blood left in the ventricles following systole [SV = EDV - ESV]. For example, if EDV is 120 ml and ESV is 50 ml then SV will be equal to 70 ml.
Coronary circulation - cardiac muscle is one of the most _______________ active tissues and requires a constant supply of ________ for nourishment.
Coronary circulation - cardiac muscle is one of the most metabolically active tissues and requires a constant supply of blood for nourishment.
Defibrillation - reversal of ____________, through passing electrical current through the heart leading to complete depolarization of the heart in hopes of a normal cycle post.
Defibrillation - reversal of fibrillation, through passing electrical current through the heart leading to complete depolarization of the heart in hopes of a normal cycle post.
ECG - Electrocardiogram - this is a measure of the __________ activity of the heart. Each cardiac cycle shows a complex wave from designated by the letters _, _, _, _, and _.
ECG - Electrocardiogram - this is a measure of the electrical activity of the heart. Each cardiac cycle shows a complex wave from designated by the letters P, Q, R, S, and T.
Fibrillation - condition which frequently follows a _____ ______ need to be corrected or will result in death. Heart loses synchrony.
Fibrillation - condition which frequently follows a heart attack need to be corrected or will result in death. Heart loses synchrony.
Function of the heart- pump ______, provides ________ for moving blood throughout the vessels, the capillaries. Provides _____ _______ which bathes all of the cells.
Function - pump blood, provides pressure for moving blood throughout the vessels, the capillaries. Provides tissues fluid which bathes all of the cells.
Functional syncytium - a syncytium is a multinucleated mass of __________ which is not divided into cells by membranes. The heart is divided into cells, but because the ____ __________ provide no barrier to the action potential it moves over the entire mass of the cardiac muscle as if it were a single large cell.
Functional syncytium - a syncytium is a multinucleated mass of protoplasm which is not divided into cells by membranes. The heart is divided into cells, but because the gap junctions provide no barrier to the action potential it moves over the entire mass of the cardiac muscle as if it were a single large cell.
Heart attack (coronary occlusion, myocardial infarction) means there is a blockage of a ____________ artery, also depends on the amount of blockage. Which results in damage and death of given section of heart muscle, resulting in _____ ________ hindering correct function.
Heart attack (coronary occlusion, myocardial infarction) means there is a blockage of a coronary artery, also depends on the amount of blockage. Which results in damage and death of given section of heart muscle, resulting in scar tissue hindering correct function.
Heart blocks - these involve malfunctions in the _____________ system.
Heart blocks - these involve malfunctions in the conducting system.
________ _________ - squishy sound, valve is not closing completely causing back flow.
Heart murmur - squishy sound, valve is not closing completely causing back flow.
the following are some of the kinds of information that can be obtained from an ECG
Heart rate Rhythmicity Conducting system efficiency Presence of ischemia Presence and location of scar tissue Relative position of the heart in the chest
Heart sounds "lub-dub" - a stethoscope detects two heart sounds during the cardiac cycle - 1. The first sound "lub" - due to closing of __ _______ (sound is actually the blood rubbing). 2. The second sound "dub" - due to closing of ________ _____.
Heart sounds "lub-dub" - a stethoscope detects two heart sounds during the cardiac cycle - 1. The first sound "lub" - due to closing of AV valves (sound is actually the blood rubbing). 2. The second sound "dub" - due to closing of semilunar valves.
Hormonal control - ________ and ____________ released by adrenal glands increase SA node in heart.
Hormonal control - Epinephrine and norepinephrine released by adrenal glands increase SA node in heart.
If the ______ side fails, the blood backs up into pulmonary circulation which results in blood pooling in lungs which is known as ___________ ________.
If the left side fails, the blood backs up into pulmonary circulation which results in blood pooling in lungs which is known as pulmonary edema.
If the _______ side fails, the blood backs up into the ____________ system resulting in peripheral edema.
If the right side fails, the blood backs up into the systemic system resulting in peripheral edema.
Origin and conduction of the heart beat : Inherent excitability - cardiac muscle will spontaneously __________ because of specialized cells which make up the ________ system. Represents 1% of heart cells. The first cell to depolarize will spread to the next cell via the gap junction and serve as pacemaker.
Inherent excitability - cardiac muscle will spontaneously depolarize because of specialized cells which make up the nodal system. Represents 1% of heart cells. The first cell to depolarize will spread to the next cell via the gap junction and serve as pacemaker.
Left and Right Atria - two _______ chambers. The right atria _______ blood from the inferior and superior vena cava veins. Left atria _______ blood via __ pulmonary veins, __ from left, __ from right.
Left and Right Atria - two upper chambers. The right atria receives blood from the inferior and superior vena cava veins. Left atria receives blood via 4 pulmonary veins, 2 from left, 2 from right.
Left and right ventricles - these are the _________ chambers which pump blood into either the ________ circuit or the __________ circuit. The right pumps the blood into the __________ _____, then into the _________ ________ which go to the lungs. The left pumps out through the ______ and to the _________ path.
Left and right ventricles - these are the lower chambers which pump blood into either the systemic circuit or the pulmonary circuit. The right pumps the blood into the pulmonary trunk, then into the pulmonary arteries which go to the lungs. The left pumps out through the aorta and to the systemic path.
Location - The heart lies in a space between the lung which is termed the ___________. Base of the heart lies beneath the ___________, apex points to the left.
Location - The heart lies in a space between the lung which is termed the mediastinum. Base of the heart lies beneath the sternum, apex points to the left.
_________ _________ - this is the most immediate and important mechanism for altering heart rate. It utilizes cardiac reflex centers located in the medulla and both divisions of the ANS.
Nervous control - this is the most immediate and important mechanism for altering heart rate. It utilizes cardiac reflex centers located in the medulla and both divisions of the ANS.
Origin - in a normal heart there are a special group of cells in the wall of the right atrium known as _________ (___) node. This is where a heartbeat originates.
Origin - in a normal heart there are a special group of cells in the wall of the right atrium known as sinoatrial (SA) node. This is where a heartbeat originates.
P wave - represents ____________ of the atrium
P wave - represents depolarization of the atrium
PR interval - time it takes for the _ wave to the _ portion of the ___ (1.6 seconds to happen, if over 2 there is a problem).
PR interval - time it takes for the P wave to the R portion of the QRS (1.6 seconds to happen, if over 2 there is a problem).
_______________ - double layer membrane which surrounds the heart
Pericardium - double layer membrane which surrounds the heart
Phases - there are two major phases to the cardiac cycle, _______ (contraction) and ________ (relaxation). During systole blood is being ________ from the heart and during diastole the heart is __________ ___.
Phases - there are two major phases to the cardiac cycle, systole (contraction) and diastole (relaxation). During systole blood is being expelled from the heart and during diastole the heart is filling up.
Physiology of the heart - Although the heart is composed of several tissues it is predominantly ________ ________. The physiology of the heart is really the physiology of cardiac muscle.
Physiology of the heart - Although the heart is composed of several tissues it is predominantly cardiac muscle. The physiology of the heart is really the physiology of cardiac muscle.
Plateau - an extended period of ______________ due to opening of voltage regulated calcium channels called slow channels. Stay open for longer periods of time.
Plateau - an extended period of depolarization due to opening of voltage regulated calcium channels called slow channels. Stay open for longer periods of time.
Premature beat (preventricular contraction PVC) is an extra ______ of a ventricle or ectopic focus, usually caused by caffeine.
Premature beat (preventricular contraction PVC) is an extra beat of a ventricle or ectopic focus, usually caused by caffeine.
QRS interval - _____________ of ventricles (.08 seconds, if 1 second there is a problem).
QRS interval - depolarization of ventricles (.08 seconds, if 1 second there is a problem).
QRS wave - represents ___________ of the ventricles
QRS wave - represents depolarization of the ventricles
Rapid depolarization - same as skeletal muscle must meet ________ regulated channels allowing ______ to pass through fast channels.
Rapid depolarization - same as skeletal muscle must meet sodium regulated channels allowing sodium to pass through fast channels.
There are three major aspects to this AP -
Rapid depolarization, Plateau, Repolarization
Regulation - tissues have to have a constant supply of ________. The ultimate regulating factor for cardiac output.
Regulation - tissues have to have a constant supply of oxygen. The ultimate regulating factor for cardiac output.
Regulation of heart rate - The alteration of heart rate is the most important factor in regulating cardiac output. Normal resting heart rate can rage from the __ to ___ BPM with 70 being about average. Heart rate can be altered by nervous and hormonal mechanisms. Factors that increase HR are said to be __________ chronotropic while those that decrease it are ___________ chronotropic.
Regulation of heart rate - The alteration of heart rate is the most important factor in regulating cardiac output. Normal resting heart rate can rage from the 40 to 100 BPM with 70 being about average. Heart rate can be altered by nervous and hormonal mechanisms. Factors that increase HR are said to be positively chronotropic while those that decrease it are negatively chronotropic.
Repolarization - calcium (slow) channels begin to _____ and slow. ____________ channels will open. Brings on rapid repolarization which restores resting potential. Back down to -__ mv.
Repolarization - calcium (slow) channels begin to close and slow. Potassium channels will open. Brings on rapid repolarization which restores resting potential. Back down to -90 mv.
Risk factors of heart disease - high blood cholesterol, high blood pressure, smoking, obesity, non-exercise, diabetes, genetics.
Risk factors of heart disease - high blood cholesterol, high blood pressure, smoking, obesity, non-exercise, diabetes, genetics
SA node > atrial myocardium > AV node > bundle of his (AV bundle) > right and left bundle branches > Purkinje fibers (subendocardial conducting network) > ventricular myocardium
SA node > atrial myocardium > AV node > bundle of his (AV bundle) > right and left bundle branches > Purkinje fibers (subendocardial conducting network) > ventricular myocardium
Semilunar valves (2) - these separate the arteries from the ventricles - they are the ________ semilunar and the _______ semilunar.
Semilunar valves (2) - these separate the arteries from the ventricles - Pulmonic semilunar - Aortic semilunar
Size and shape - ______ shape, pointed end called the _____, broad portion called the base.
Size and shape - cone shape, pointed end called the apex, broad portion called the base.
_________ law of the heart - This law simply states that within limits, the heart will pump out all of the blood it receives. Output will be equal to input.
Starlings law of the heart - This law simply states that within limits, the heart will pump out all of the blood it receives. Output will be equal to input.
Structure of the heart - hollow ________ organ, has __ chambers, each with ___ openings. One for blood to _____, the other for blood to ____.
Structure - hollow muscular organ, has 4 chambers, each with 2 openings. One for blood to enter, the other for blood to exit.
T wave - _______________ of the ventricles
T wave - repolarization of the ventricles
The amount of stretching (preload) is directly proportional to the ___. *So the more blood that returns during diastole, the greater the ________. Thus the greater the force of contraction.
The amount of stretching (preload) is directly proportional to the EDV. *So the more blood that returns during diastole, the greater the stretch. Thus the greater the force of contraction.
The atrioventricular valves prevent the ______ ______ of blood into the atria during ventricular contraction.
The atrioventricular valves prevent the back flow of blood into the atria during ventricular contraction.
The cardiovascular system consists of the _______, the _______ ________, and the ________.
The cardiovascular system consists of the blood, the blood vessel, and the heart.
The details of the cycle are as follows - 1. At mid diastole, pressure in atria is _________ than the ventricles. AV valves open, blood rushes _____ the ventricles. Nearly __% of total volume of blood flows in with gravity, remaining __% from the effort of the heart. 2. Atrial systole begins when last of remaining blood is forced into the _________. 3. Ventricular systole begins as soon as the ventricles begin to __________. The __________ within exceeds that of the atrium. AV valves will _____, semilunar valves are not yet open, so pressure inside ventricles will _______. This is called isovolumetric contraction period (blood's inside ventricles). 4. Ventricular ejection period occurs when the pressure within the ventricles __________ that of the pulmonary trunk and the aorta, so the semilunar valves ________. 5. Blood is being forced into the arteries causing _________ pressure and in turn, decreasing pressure in the ventricles. Semilunar valves will then _______. This isovolumetric relaxation period is the period of time when all valves are closed during _________. 6. The ventricles continue to relax, pressure is less than that of atrium which will _________ AV valves. Thus beginning the cycle all over again.
The details of the cycle are as follows - 1. At mid diastole, pressure in atria is greater than the ventricles. AV valves open, blood rushes into the ventricles. Nearly 75% of total volume of blood flows in with gravity, remaining 25% from the effort of the heart. 2. Atrial systole begins when last of remaining blood is forced into the ventricles. 3. Ventricular systole begins as soon as the ventricles begin to contract. The pressure within exceeds that of the atrium. AV valves will close, semilunar valves are not yet open, so pressure inside ventricles will increase. This is called isovolumetric contraction period (blood's inside ventricles). 4. Ventricular ejection period occurs when the pressure within the ventricles exceeds that of the pulmonary trunk and the aorta, so the semilunar valves open. 5. Blood is being forced into the arteries causing increased pressure and in turn, decreasing pressure in the ventricles. Semilunar valves will then close. This isovolumetric relaxation period is the period of time when all valves are closed during diastole. 6. The ventricles continue to relax, pressure is less than that of atrium which will reopen AV valves. Thus beginning the cycle all over again.
The semilunar valves prevent the back flow of blood from the ________ into the ventricles during ventricular relaxation. Each valve has three pockets or cusps which ________ out when blood leaves the ventricles. When blood begins to flow back towards the ventricles the pockets ________ _________ and come together to form a seal.
The semilunar valves prevent the back flow of blood from the arteries into the ventricles during ventricular relaxation. Each valve has three pockets or cusps which flatten out when blood leaves the ventricles. When blood begins to flow back towards the ventricles the pockets balloon outward and come together to form a seal.
This blood is supplied to the heart through the following vessels - a. The aorta gives rise to the right and left __________ artery. b. The right coronary artery courses to the ________ side of the heart, where it also gives rise to two branches: the _________ ___________ artery which supplies the posterior surface of both ventricles and also the right marginal artery which serves the myocardium. Together the branches of the right coronary artery supply the right atrium and right ventricle. c. The left coronary artery divides to form the ________ __________ artery which supplies the anterior surface of both ventricles as well as the _________ artery which supplies the posterior of both the left atrium and ventricle. d. After passing through an extensive capillary network the blood is drained from the myocardium by the _______ veins. The cardiac veins join to form a large vessel, the ___________ sinus, which drains into the right atrium, along with the anterior cardiac vein. Blockage of the coronary arteries leads to a condition known as a ________ ___________ or a _______ _________.
This blood is supplied through the following vessels - a. The aorta gives rise to the right and left coronary artery. b. The right coronary artery courses to the right side of the heart, where it also gives rise to two branches: the posterior interventricular artery which supplies the posterior surface of both ventricles and also the right marginal artery which serves the myocardium. Together the branches of the right coronary artery supply the right atrium and right ventricle. c. The left coronary artery divides to form the anterior interventricular artery which supplies the anterior surface of both ventricles as well as the circumflex artery which supplies the posterior of both the left atrium and ventricle. d. After passing through an extensive capillary network the blood is drained from the myocardium by the cardiac veins. The cardiac veins join to form a large vessel, the coronary sinus, which drains into the right atrium, along with the anterior cardiac vein. Blockage of the coronary arteries leads to a condition known as a myocardial infarction or a heart attack.
Tricuspid - __ flap valve located between right atrium and right ventricle.
Tricuspid - 3 flap valve located between right atrium and right ventricle.
Valves - the flow of _________ through the heart is regulated by ______ valves.
Valves - the flow of blood through the heart is regulated by four valves
Wal structure - the wall of the heart is built in three layers which are as follows -
Wal structure - the wall of the heart is built in three layers which are as follows -endocardium, myocardium, epicardium
The atrioventricular valves prevent the back flow in the following manner: a. when blood flows into atria and ventricles the __________ of the incoming blood forces the valves open. b. when ventricles begin to contract, the pressure causes the valve to ______ _____. c. the valves are prevented from opening by connective tissue strands called _______ ________.
a. when blood flows into atria and ventricles the pressure of the incoming blood forces the valves open. b. when ventricles begin to contract, the pressure causes the valve to swing shut. c. the valves are prevented from opening by connective tissue strands called chordae tendinae.
________ _________ - the cardiac control centers receive a wide variety of inputs from receptors located in various parts of the body and other parts of the brain. Therefore, many different changes that occur in the other parts of the body as well as in the nervous system can alter heart rate.
afferent pathways - the cardiac control centers receive a wide variety of inputs from receptors located in various parts of the body and other parts of the brain. Therefore, many different changes that occur in the other parts of the body as well as in the nervous system can alter heart rate.
________ ________ __________ - these are located in the medulla. There are two centers, the cardiac accelerator center which speeds up the heart and the cardiac inhibitor center which slows down the heart rate.
cardiac control centers - these are located in the medulla. There are two centers, the cardiac accelerator center which speeds up the heart and the cardiac inhibitor center which slows down the heart rate.
complete blocks - no _________ goes to ventricles.
complete blocks - no impulse goes to ventricles.
Cardiac output - Definition: This is the amount of blood pumped by one ___________ per minute. It is equal to the heart rate times the stroke volume (volume of blood expelled per beat).
eCardiac output - Definition: This is the amount of blood pumped by one ventricle per minute. It is equal to the heart rate times the stroke volume (volume of blood expelled per beat).
efferent pathways - the cardiac accelerator center exercises control through the ____________ division of the ANS. Fiber from the cardiac nerves terminate in the heart and release ________________ which speeds up the heart rate. The cardiac inhibitor center works through the ______________ division of the ANS. Fibers from the vagus nerve release _____________ on the heart muscle slowing it down.
efferent pathways - the cardiac accelerator center exercises control through the sympathetic division of the ANS. Fiber from the cardiac nerves terminate in the heart and release norepinephrine which speeds up the heart rate. The cardiac inhibitor center works through the parasympathetic division of the ANS. Fibers from the vagus nerve release acetylcholine on the heart muscle slowing it down.
endocardium - lining of the _______, inside, consists of a single layer of _________ epithelium. It's continuous with the endothelium which lines the remainder of the _________ system. When it folds and combines with connective tissues of the heart, it forms ________.
endocardium - lining of the heart, inside, consists of a single layer of squamous epithelium. It's continuous with the endothelium which lines the remainder of the circulatory system. When it folds and combines with connective tissues of the heart, it forms valves.
epicardium - very ____, _____ membrane, visceral pericardial membrane. Regulate blood flow from _____ to _________ one one either side of heart.
epicardium - very thin, serous membrane, visceral pericardial membrane. Regulate blood flow from atria to ventricles one one either side of heart.
hormones - ________ and _________ and ___________ (from pancreas which breaks down stored glucose) have positive effect on heart.
hormones - epinephrine and norepinephrine and glucagon (from pancreas which breaks down stored glucose) have positive effect on heart.
myocardium - 3 layers of muscle. Very thin in atria, much thicker in ventricles. The left has 4 layers because of its additional pressure. Inner surface of muscle is folded to form cone shaped papillary muscles.
myocardium - 3 layers of muscle. Very thin in atria, much thicker in ventricles. The left has 4 layers because of its additional pressure. Inner surface of muscle is folded to form cone shaped papillary muscles.
__________ layer - tough fibrous membrane forming the outer layer.
parietal layer - tough fibrous membrane forming the outer layer.
Partial blocks - ______________, wave is delayed and the AV node. May have 3, 4, or more signals means it's delayed.
partial blocks - depolarization, wave is delayed and the AV node. May have 3, 4, or more signals means it's delayed.
___________ _______ - space between both membranes filled with pericardial fluid which functions to reduce friction.
pericardial cavity - space between both membranes filled with pericardial fluid which functions to reduce friction.
Path of blood through the heart - beginning with the vena cava, a drop of blood would pass through the following structures on its path through the heart
superior and inferior vena cava > coronary sinus > right atrium > tricuspid valve > right ventricle > pulmonary semilunar valve > pulmonary trunk > pulmonary right and left arteries > lungs > pulmonary veins (4) > left atrium > bicuspid (mitral) valve > left ventricle > aortic semilunar valve > aorta > systemic circuit.
_____________ stimulation - if intense stimulation by the sympathetic nerves, can increase the force of contraction about 100% above normal.
sympathetic stimulation - if intense stimulation by the sympathetic nerves, can increase the force of contraction about 100% above normal.
_______ layer (____________) - inner layer, more delicate serous layer and very closely adheres to the heart.
visceral layer (epicardium) - inner layer, more delicate serous layer and very closely adheres to the heart.