Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
132 Cards in this Set
- Front
- Back
|
What is the function of the pulmonary circuit?
|
Carries blood to and from gas exchange surfaces of lungs |
|
|
What is the function of the systemic circuit?
|
Blood alternates between pulmonary circuit and systemic circuit |
|
|
What are the three types of blood vessels?
|
Veins Capillaries |
|
|
What is the function of the arteries?
|
Carries blood away from the heart
|
|
|
What is the function of the veins?
|
Carries blood to the heart |
|
|
What are the functions of the capillaries?
|
Also called exchange vessels Materials include dissolved gases, nutrients, and waste products |
|
|
What is the shape of the heart at birth?
|
Transverse |
|
|
At what age does the heart attain its adult shape and weight?
|
Puberty - 25 years
|
|
|
Where is the heart located>
|
In the mediastinum |
|
|
What is the name of the membrane that surrounds the heart? |
Pericardium |
|
|
What is the function of the pericardium?
|
Surrounds and protects the heart by confining it while still allowing free movement |
|
|
What are the parts of the pericardium?
|
|
|
|
What are the characteristics of the fibrous pericardium?
|
|
|
|
What is the function of the fibrous pericardium? |
Prevents overstretching, provides protection and anchorage |
|
|
What are the characteristics of the serous pericardium?
|
Double layer |
|
|
What is the function of the pericardial fluid?
|
Secreted by the pericardial cavity Reduces friction |
|
|
What are the layers of the heart?
|
Myocardium Endocardium |
|
|
What is the epicardium?
|
Visceral, external layer of serous pericardium
|
|
|
What is the myocardium?
|
95% of the heart, the thickest |
|
|
What is the endocardium? |
The inner most part of the heart, smooth lining for chambers of heart, valves, and vessels |
|
|
What are the four chambers of the heart?
|
Right Atrium Right Ventricle Left Atrium Left Ventricle |
|
|
What is the function of the right atrium?
|
Collects blood from systemic circuit |
|
|
What is the function of the right ventricle? |
Pumps blood to pulmonary circuit |
|
|
What is the function of the left atrium?
|
Collects blood from pulmonary circuit |
|
|
What is the function of the left ventricle?
|
Pumps blood to systemic circuit |
|
|
What is the sulci?
|
-Contain coronary blood vessels -Coronary sulcus -Anterior interventricular sulcus |
|
|
Where does the right atrium receive blood from?
|
Inferior vena cava Coronary sinus |
|
|
What is the function of the interatrial septum?
|
Separates the right and left atrium |
|
|
What is the tricuspid valve?
|
Separates right atrium from right ventricle |
|
|
What is the trabeculae carneae?
|
Ridges formed by raised bundles of cardiac muscle fiber -Part of conduction system of the heart |
|
|
What are the characteristics of the left atrium? |
Left atrioventricular valve Bicuspid (mitral) Separates left atrium from left ventricle |
|
|
How does the left atrium receive blood?
|
Passes blood through bicuspid valve into left ventricle |
|
|
What are the characteristics of the left ventricle?
|
Chordae tendinae attached to papillary muscles |
|
|
How does blood flow through the left ventricle?
|
Some blood flows into coronary arteries, remainder to body |
|
|
The tri and bicuspid valves are also known as what?
|
The atrioventricular valves
|
|
|
What happens when the atria contracts and the ventricles are relaxed?
|
AV valves open, cusps project into ventricles Ventricles: papillary muscles are relaxed & chordae tendinae are slack |
|
|
What happens when atria relax and ventricles contract?
|
Papillary muscles contract tightening chordae tendinae -Prevents regurgitation |
|
|
Why is it not necessary for valves to guard the atria entrance?
|
As atria contract, they compress and nearly collapse the venous entry points |
|
|
When do valves open?
|
When pressure in the ventricle exceeds pressure in arteries |
|
|
When do valves relax?
|
Some back flow is permitted but blood fills valve cusps closing them tightly |
|
|
What is the pathway of blood through the heart & lungs?
|
Pulmonary Circulation |
|
|
The blood supply to the heart is also known as what?
|
|
|
|
What is the function of coronary circulation?
|
|
|
|
What are the coronary arteries?
|
Originate at aortic sinuses |
|
|
How does blood move through the coronary arteries? |
High blood pressure, elastic rebound forces blood through coronary arteries between contractions
|
|
|
The right coronary artery supplies blood to where?
|
Portions of both ventricles Cells of sinoatrial (SA) and atrioventricular nodes Marginal arteries (surface of right ventricle) Posterior interventricular artery |
|
|
The left coronary artery supplies blood to where?
|
Left atrium Interventricular septum |
|
|
What are the two main branches of the left coronary artery?
|
Anterior interventricular artery |
|
|
What is the function of the arterial anastomoses?
|
Stabilize blood supply to cardiac muscle |
|
|
What are the cardiac veins?
|
Anterior cardiac vein Posterior cardiac vein Middle cardiac vein Small cardiac vein |
|
|
What is the function of the great cardiac vein?
|
Drains blood from area of anterior interventricular artery into coronary sinus |
|
|
What is the function of the anterior cardiac veins? |
Empty into right atrium |
|
|
What is the function of the posterior, middle, and small cardiac veins? |
Empty into great cardiac vein or coronary sinus |
|
|
For one third of people with heart problems what is the first symptom?
|
Sudden death :( |
|
|
What is Coronary Artery Disease?
|
Areas of partial or complete blockage of coronary circulation |
|
|
Cardiac muscle cells need a constant supply of what?
|
Oxygen and nutrients |
|
|
The reduction in blood flow to heart muscles produces what? |
A corresponding reduction in cardiac performance |
|
|
What is coronary ischemia and what is it a result of?
|
A reduce in circulatory supply as a result from a partial or complete blockage of coronary arteries |
|
|
What is most often one of the first symptoms of CAD?
|
Angina pectoris |
|
|
What are some of the causes of CAD? |
Formation of a fatty deposit, or atherosclerotic plaque, in the wall of a coronary vessel The plaque, or an associated thrombus (clot), then narrows the passageway and reduces blood flow Spasms in smooth muscles of vessel wall can further decrease or stop blood flow |
|
|
What is angina pectoris?
|
Meaning that a individual may feel comfortable at rest but exertion or emotional stress can produce a sensation of pressure, chest constriction, and pain that may radiate from the sternal area to the arm, back, and neck |
|
|
What is another term for a myocardial infarction (MI)?
|
A heart attack |
|
|
What happens to cause an MI? |
Part of the coronary circulation becomes blocked, and cardiac muscle cells die from lack of oxygen
|
|
|
The death of affected tissue creates a nonfunctional area known as what?
|
An infarct |
|
|
Severe coronary artery disease commonly results in what? |
A heart attack |
|
|
A crisis develops as a result of thrombus formation at a plaque, a condition called what?
|
Coronary Thrombosis |
|
|
A vessel narrowed by plaque formation may also become blocked how?
|
By a sudden spasm in the smooth muscle of the vascular wall |
|
|
How do you diagnose an MI? |
ECG and blood studies |
|
|
What enzymes are released into circulation during an MI?
|
Cardiac troponin I A special form of creatinine phosphokinase, CK-MB |
|
|
What happens to about 25% of MI patients before they obtain medical assistance?
|
They die
|
|
|
65% of MI deaths among those under age 50 occur when?
|
Within an hour after the infarction |
|
|
How can you lower your risk of CAD or an MI?
|
Treatment of high blood pressure Modify diet to lower cholesterol and promote weight loss Reduce stress Increase physical activity where appropriate |
|
|
What drug treatments can be used to treat or lower your risk of CAD or an MI?
|
Aspirin, Coumadin Propranolol or metoprolol Nitroglycerin Calcium channel blockers |
|
|
What is an atherectomy?
|
A noninvasive surgery where a blockage by a single, soft plaque may be reduced with the aid of a long, slender catheter inserted into a coronary artery to the plaque
|
|
|
What are the types of surgeries to help treat CAD and MI?
|
Noninvasive -Atherectomy -Balloon Angioplasty Invasive -Coronary Artery Bypass Graft (CABG) |
|
|
What is a balloon angioplasty?
|
Once in position, the balloon is inflated, pressing the plaque against the vessel walls |
|
|
What is a stent and why is it used? |
It is a fine tubular wire mesh used because plaque commonly redevelops after angioplasty |
|
|
What is a Coronary Artery Bypass Graft?
|
When a small section is removed from either a small artery or a peripheral vein and is used to create a detour around the obstructed portion of a coronary artery |
|
|
How many coronary arteries can be rerouted during a single operation?
|
As many as four |
|
|
What are the procedures in a CABG named for? |
They are named according to the number of vessels repaired so we speak of single, double, triple, or quadruple coronary bypasses |
|
|
What are common cardiac diseases?
|
Ischemia Angina Pectoris |
|
|
What is ischemia? |
A condition of reduced blood flow |
|
|
What is angina pectoris?
|
A painful condition where a pain in the chest and left arm occurs |
|
|
A coronary bypass operation does what?
|
Takes a leg vein and attaches one end to the aorta and the other end to a coronary artery past the point of obstruction About 500,000 per year are preformed |
|
|
What are the characteristics of cardiac muscle cells?
|
Single, central nucleus Branching interconnections between cells Intercalated discs |
|
|
What are intercalated discs?
|
Secured by desmosomes Linked by gap junctions Convey force of contraction Propagate action potentials |
|
|
What are Autorhythmic Fibers?
|
Cardiac muscle has built-in or innate ability to contract (even removed it will keep beating) The reason for this is a unique type of tissue called nodal tissue, having both muscular and nervous characteristics |
|
|
SA node generates how many action potentials per minute?
|
80-100 action potentials per minute |
|
|
What stimulation slows heart rate?
|
Parasympathetic stimulation |
|
|
AV node generates how many action potentials per minute? |
40-60 action potentials per minute |
|
|
The sinoatrial node is also known as what?
|
the pacemaker |
|
|
Where is the atrioventricular node (AV node) located?
|
at the lower right atrium near the septum and receives impulses from the SA node |
|
|
AV node relays impulses to where?
|
The specialized cells of the bundle of HIS (AKA the AV bundle) in the interventricular septum |
|
|
Action potential continues along where?
|
The interventricular septum by bundle branches, and ultimately specialized fibers called Purkinje Fibers; causing ventricles to contract |
|
|
What is arrhythmias?
|
Any disturbance in the rate of the heartbeat |
|
|
What is Bradycardia?
|
Abnormally slow heart rate |
|
|
What is Tachycardia?
|
Abnormally rapid heart rate |
|
|
What is a flutter?
|
Heart is beating much faster, 250-300 beats per minute which doesn't give the chambers time to fill between beats |
|
|
What is fibrillation? |
-Immediately life threatening -Use of defibrillator shocks the heart, which then may reset itself |
|
|
What are the abnormal pacemaker functions?
|
Tachycardia Ectopic pacemaker |
|
|
What happens when you have an ectopic pacemaker? |
Abnormal cells Generate high rate of action potential Bypass conducting system Disrupt ventricular contractions |
|
|
What is depolarization?
|
-Na+ channels open (Na+ flows in) -Then deactivate and Na+ inflow decreases |
|
|
What is a plateau?
|
Due in part to opening of voltage-gated slow Ca2+ channels -Ca2+ moves from interstitial fluid into cytosol Ultimately triggers contraction Depolarization sustained due to voltage-gated K+ channels balancing Ca2+ inflow with K+ outflow |
|
|
What is repolarization?
|
Recovery of resting membrane potential Additional voltage-gated K+ channels open Outflow of K+ restores negative resting membrane potential Calcium channels close |
|
|
What is a refractory period?
|
Lasts longer than contraction itself Tetanus (maintained contraction) cannot occur |
|
|
What is an ECG or EKG?
|
Composite record of action potentials produced by all the heart muscle fibers |
|
|
What are the 3 recognizable waves on an EKG or ECK?
|
P, QRS, & T |
|
|
What are the two phases of the cardiac cycle within any one chamber?
|
Diastole (relaxation) |
|
|
How do the two phases of the cardiac cycle work?
|
-P wave appears Atrial contraction (atrial systole) Action potential enters AV bundle and out over ventricles -QRS complex Masks atrial repolarization Contraction of ventricles (ventricular systole) -Begins Shortly after QRS complex appears and continues during S-T segment Repolarization of ventricular fibers -T wave Ventricular relaxation (diastole) |
|
|
How does blood pressure react during the cardiac cycle in the chambers?
|
In all chambers bp rises during systole and falls during diastole |
|
|
How does blood flow from high to low pressure during the cardiac cycle?
|
Directed by one-way valves |
|
|
When the heart beats at 75 bpm the cardiac cycle lasts how long?
|
About 800msec |
|
|
What happens to the phases of cardiac cycle when the heart rate increases?
|
All phases of cardiac cycle shorten, particularly diastole |
|
|
Atria and ventricles alternately contract and relax, during atrial systole what happens to the ventricles?
|
Ventricles are relaxed |
|
|
Atria and ventricles alternately contract and relax, during ventricle systole what happens to the atria?
|
Atria are relaxed |
|
|
Atria and ventricles alternately contract and relax forces blood pressure what direction? |
Forces blood pressure from high to low pressure |
|
|
What happens to the atria and ventricles during relaxation period?
|
Both are relaxed, faster the heart beats, shorter the relaxation period |
|
|
What is auscultation?
|
|
|
|
How many heart sounds are in each cardiac cycle?
|
Lubb- (S1)AV valve closes Dupp- (S2)SL valve closes |
|
|
What is a heart murmur?
|
There may be a backflow of blood which causes a slushing sound Some heart murmurs may be due to Rheumatic Fever (Streptococcus) Valves today can be operated on or replaced |
|
|
What is cardiac output?
|
It is the product of the number of heartbeats per minute and the volume of blood pumped by one ventricle during a contraction |
|
|
What is the equation of cardiac output? |
Cardiac Output = Stroke Volume x Heart Rate (ml/min) = (ml) x (bpm) |
|
|
What factors affect cardiac output?
|
Cardiac Output -Adjusted by changes in heart rate or stroke volume Heart Rate -Adjusted by autonomic nervous system or hormones Stroke volume- left ventricle -Adjusted by changing (EDV&ESV) --End diastolic volume --End systolic volume |
|
|
What is congestive heart failure?
|
Pump becomes less effective = more blood left in ventricles Increased preload occurs Forcing ventricles to stretch Blood backs up in lungs causing pulmonary edema |
|
|
What is autonomic innervation?
|
Vagus nerves (N X) carry parasympathetic preganglionic fibers to small ganglia in cardiac plexus Cardiac centers of medulla oblongata Cardioacceleratory center controls sympathetic neurons (increases heart rate) Cardioinhibitory center controls parasympathetic neurons (slows heart rate) |
|
|
Cardiovascular center in the medulla also monitors what?
|
They are receptors sensitive to blood pressure, so that the medulla can respond by changing heart beat rate |
|
|
What is the function of cardiac reflexes in autonomic innervation?
|
Cardiac centers monitor blood pressure (baroreceptors), arterial oxygen and carbon dioxide levels (chemoreceptors) Cardiac centers adjust cardiac activity |
|
|
What does autonomic tone do? |
Fine adjustment meet needs of other systems |
|
|
What are the effects of autonomic activity on contractility during sympathetic stimulation?
|
NE released by postganglionic fibers of cardiac nerves Epinephrine and NE released by adrenal medullae Causes ventricles to contract with more force Increases ejection fraction and decreases ESV |
|
|
What are the effects of autonomic activity on contractility during parasympathetic stimulation?
|
Acetylcholine released by vagus nerves Reduces force of cardiac contractions |
|
|
Many hormones affect what?
|
Pharmaceutical drugs mimic hormone actions -Stimulate or block beta receptors -Affect calcium ions (e.g., calcium channel blockers) |
|
|
|
|
