Cardiac Anatomy And Physiology Flashcards
Define the following anatomical terms:
Sagittal, transverse, or horizontal
Sagittal: lengthwise Plain, that divides the body into left and right sections
Transverse or horizontal: crosswise cut that runs parallel to the ground and divides the body into upper and lower sections
Define the following anatomical terms:
Visceral, parietal
Visceral: the covering of the surface of the body or an organ
Parietal: the wall of the surface of the body or organ
Defined the following anatomical, terms: external, internal, distal, proximal
External: located on the outside of the body
Internal: located on the inside of the body
Distal: located away from the center of the body
Proximal: located nearest to the center of the body
Defined the following anatomical terms:
Superior, inferior, medial, lateral
Superior: toward the head or toward the surface of the body; synonymous with cephalic
Inferior: toward the feet or tail or away from the surface of the body; synonymous with “ caudal”
Medial: middle or near the middle of the body
Lateral: to the side of the body
Describe the function of the Sino atrial node in the electrical conduction system of the heart
The electrical conduction system of the heart generates and propagate the electrical impulse that contain the rhythmic contractions of the heart the entire system is composed of the sinoatrial and atrial ventricular notes and the nodule pathways, the bundle of his, as well as the right and left bundle branches, and the anterior and posterior fascicles. The SA node is often called the “pacemaker“ of the heart. The SA node is the site of the spontaneous generation of the electrical impulse that stimulates the heart to contract. The SA node is an oblong shaped group of muscle cells in the right atrium.  It is the larger of the two notes acting in the electrical conduction pathway. The SA typically generates a heartbeat at a rate of 60 to 100 bpm, but can be influenced by the autonomic nervous system to increase or decrease the heart rate.
Define the following anatomical:
Anterior or ventral, posterior or dorsal, superficial, peripheral
Anterior or ventral: near or on the front of the body
Posterior or dorsal : near or on the back of the body
superficial: toward the surface of the body
Peripheral : toward the periphery of the body; located a way from the center of the body
Describe the function of the right and left bundle branches in the electrical conduction system of the heart
The electrical conduction system of the heart generates and propagates the electrical impulses that sustain the rhythmic contractions of the heart. The entire system is composed of the Sino atrial and atrial ventricular, nodes and pathways, the bundle of his, as well as the right and left bundle branches in the anterior and posterior fascicles. The bundle of his divides to form the right and left bundle branches. The right bundle branch carries electrical impulses to the right ventricle and the left bundle branch carries electrical impulses to the left ventricle. Electrical conduction through the bundle branches is very rapid. 
Describe the factors affecting the heart rate in the electrical conduction system
The SA node is often called the “pacemaker“ of the heart. The SA node is the site of the spontaneous generation of the electrical impulse that stimulates the heart to contract. The SA node typically generates a heartbeat at a rate of 60 to 100 BPM, But can be influenced by the autonomic nervous system to increase or decrease the heart rate rate.
Substances, from the sympathetic nervous system, norepinephrine(noradrenaline), and epinephrine (adrenaline )may stimulate the SA node. In this case, the depolarization of the SA node occurs more quickly, and more action potentials are generated, leading to an increased heart rate. If the SA node is stimulated by acetylcholine, the rate of depolarization is decreased, leading to a decreased heart rate
Describe the function of the perkinje fibers in the electrical conduction system of the heart
The bundle branches divide into the perkinje fibers, located in the walls of both the right and left ventricles. These fibers form a network over the surface of the heart and penetrate into the muscles of the ventricles. Perkinje fibers deliver the electrical impulse that stimulates ventricular, depolarization and contraction. Perkinje Fibers maintain a high velocity of electrical conduction. 
Describe the function of the anterior and posterior fascicles in the electrical conduction system of the heart
The electrical conduction system of the heart generates and propagates the electrical impulses that sustain the rhythmic contractions of the heart. The entire system is composed of the SA node and AV nodes and the internodal pathways, the bundle of his, as well as the right and left bundle branches and the anterior and posterior fascicles. The left bundle branch is very short and almost immediately divide into the anterior and posterior fascicles. The posterior fascicle carries the electrical impulse to the inferior and posterior portions of the left ventricle. the anterior fascicle carries electrical impulses to the anterior and superior portions of the left ventricle. The posterior fascicle is short and broad, in relation to the anterior fascicle, and it particularly resistant to ischemic damage
Describe the control mechanisms for stroke volume, as related to cardiac output
The cardiac output is determined by multiplying the heart rate and the stroke volume. Changes in heart rate or stroke volume, therefore, affect the cardiac output. The stroke volume is controlled by both intrinsic and extrinsic factors. Factors include the heart ability to change its output, or stroke volume, in response to its input. The Frank starling law defines this phenomenon and assert that, simply, the heart will pump whatever volume of blood it receives. Extrinsic factors include contractility, the strength of cardiac contractions. The contractility is independent of the volume in the ventricle. Most factors affecting contractility affect the level of calcium inside the cell. These factors include drugs or the autonomic nervous system.
Describe the major coronary veins
Coronary veins return blood to the heart chambers after it has delivered oxygen to the heart muscle through coronary arteries. The coronary venous system is composed of the right and left cardiac venous systems. The left cardiac venous system is composed of several veins: cardiac vein, middle, cardiac vein, small cardiac vein left marginal vein, left posterior, ventricular vein, and the oblique vein. The right cardiac venous system is composed of anterior cardiac veins and right marginal veins. All of the coronary veins deliver blood directly into the right atrium through the coronary sinus, valve, and the right atrium covered by a small flap. The coronary veins run parallel to the coronary arteries on the surface of the heart
Describe aortic pulse pressure
The pressure of the aorta at its highest point, as blood flows out of the left ventricle into the aorta, is on average, 120 mmHg. The pressure slowly decreases as the ventricle stops pumping blood through the aorta, the semilunar valve closes, and the left ventricle relaxes. The difference Between the highest pressure ( systolic)and lowest pressure (diastolic) in the aorta is termed aortic pulse pressure.
The aortic pulse pressure is influenced by, First, the ability of the aorta to expand to accommodate the large volume of blood, being forced into it by the left ventricle and, second, the volume of blood pumped with each ventricle contraction. For example, and aorta that is very flexible will have a smaller pulse pressure for a given stroke volume than an aorta that is more rigid. A larger stroke volume will result in a larger pulse pressure, regardless of the flexibility of the vessel. Further, the flexibility of the aorta decreases with age, leading to a gradual increase in aortic pulse pressure
Distinguish between myocardial ischemia. Myocardial injury, and myocardial infarction.
Ischemia is defined as the lack of oxygen delivery to an organ due to the obstruction or construction of blood vessels. In myocardial ischemia, the left ventricle does not receive enough oxygenated blood. Atherosclerosis is a common cause of myocardial ischemia. The fatty plaque deposited in the coronary arteries in Ather sclerosis causes an obstruction to adequate blood flow. If ischemia persist in the heart continues to receive an inadequate, blood supply, injury, or infarction can occur in the heart muscle.
Myocardial injury occurs after a prolonged period of myocardial ischemia. If the heart muscle cannot recover adequate oxygen supply, injury, and death to the myocardial tissue can occur. Myocardial injury and ischemia are both reversible processes, if diagnose in its progression. Myocardial infarction is the death of myocardial cells causes permanent damage to the heart muscle. The damage portion of the heart is no longer able to conduct electrical impulses.
Myocardial is commonly known as a heart attack and lead to sudden death
Describe the structure and function of capillaries
Capillaries are small blood vessels that branch from the arterials in the systemic circulatory system. While arteries and arterials are composed, in part, of smooth muscle, capillaries are composed of entirely endothelial cells. They are the smallest vessels within the circulatory system and function as the exchange site for oxygen in the body. In addition, exchange of carbon dioxide, water, electrolytes, proteins, and metabolic waste products all take Place in the capillaries. Capillaries are 0.006 to 0.01 mm in diameter. The capillaries joint to form venules and veins that deliver the oxygen poor blood back to the heart.
Describe the structure and function of venules and veins
Once oxygen and nutrients are delivered to the body through the capillaries, the blood must be returned to the heart to be pumped to the lungs to receive more oxygen. The small capillaries join together to form venules, which, intern, join together to form veins to deliver blood to the heart. The venules are approximately 0.01 to 0.50 mm in diameter, and function to collect blood and expand and contract to maintain appropriate blood flow in body region. The venules join together to form veins that are 0.5 to 5.0 mm in diameter. The veins also function to regulate the proper flow of blood. Finally, the veins join to the vena cava, which carries blood to the right atrium of the heart. The smallest blood vessels are composed, almost entirely of endothelial tissue, but as the venules and veins increase in size, the smooth muscle composition increases.
Describe the function of the atrioventricular node in the electrical conduction system of the heart
The entire system is composed of the SA and AV nodes and the internodal pathways, the bundle of HIS, as well as the right and left bundle branches and the anterior and posterior fascicles. The AV node is located in the lower portion of the right atrium. The AV node receives the electrical impulse generated by the SA node via the internodal pathway. As the electrical potential arrives at the AV node, it slows in velocity and is delayed at the AV node for approximately 0.1 seconds before traveling to the bundle of HIS. The delay is required to ensure that atria have completed their contraction before the ventricles begin contracting.
Describe the function of the bundle of HIS in the electrical conduction system of the hard
After the electrical impulse is slowed in the AV node, the impulse passes to the bundle of HIS . The bundle is composed of thin, specialized muscle cells that connect the distal portion of the AV node to the RBB and LBB. The bundle of HIS is specialized for very rapid electrical conduction and the electrical impulse travels at its highest speed through the bundle
Describe the electrical conduction system of the cardiac cycle and its relationship to the ECG
First, the SA node generates a spontaneous electrical impulse that stimulates atrial contraction, corresponding to the P wave on the ECG. Next the electrical impulses reaches the AV node and slows in velocity. This corresponds to the PR segment on the ECG. The electrical impulse travels through the bundle of HIS and bundle branches, then to purkinje fibers. Purkinje fibers carry the electrical impulse that simulate the ventricles to depolarize and contract, corresponding to the QRS complex.
Explain the internodal pathway in the electrical conduction system of the heart
The internodal pathway carries electrical impulses from the SA node to the AV node. The internodal pathway also carries the electrical impulse to both the right and left atria and simulates atrial contraction. This conduction occurs rapidly because the muscle cells of the atria are large and have a large negative resting potential. This produces a very rapid depolarization and subsequent conduction of electrical impulse
Explain the internodal pathway in the electrical conduction system of the heart
The internodal pathway carries electrical impulses from the SA node to the AV node. The internodal pathway also carries the electrical impulse to both the right and left atria and simulates atrial contraction. This conduction occurs rapidly because the muscle cells of the atria are large and have a large negative resting potential. This produces a very rapid depolarization and subsequent conduction of electrical impulse
Explain how to determine cardiac output
Cardiac output is the amount of blood pumped from the LV through the aorta to the rest of the body in one minute. Since the right and left sides of the heart must pump the same amount of blood over a given period of time, the average output of the RV is equal to that of the LV. The average cardiac output for a resting adult male is 5 L per minute. The stroke volume is the amount of blood pumped with each heartbeat. This can be calculated by finding the difference between the end diastolic volume and end systolic volume.
Cardiac output found by multiplying the stroke volume by the number of beats per minute. CO=HR x SV
Describe the control mechanisms for heart rate, as related to cardiac output
CO=HR x SV: changes in heart rate or stroke volume, therefore, affect the cardiac output. Heart rate is determined by spontaneous depolarization of the SA node. The depolarization of the SA node can be controlled by outside influences, including hormones, electrolytes, body temperature, and the autonomic nervous system. For example, norepinephrine and acetylcholine aretransmitters within the autonomic nervous system and act to increase or decrease the heart, respectively. Increasing the heart rate results in limited effects on cardiac output. First, the upper limit of the heart is approximately 250 bpm. Second, with rapid heart rates, cardiac output actually decreases. There is not enough time in between beats for the ventricles to fill with blood so each beat pumps less blood to the body
