Reading...
Play button
Play button
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;
40 Cards in this Set
- Front
- Back
|
Heart location
|
Lies between the lungs, resting on the diaphragm, in the midline (base and apex). From mediastinum which is the medial cavity of the thorax, the heart extends obliquely from 2 to 5 rib intercostal space.
|
|
|
What is pericardium? What are the two layers and what are the 2 components of the inner layer? What is pericardial cavity and what is it filled with?
|
Supports and protects heart from over stretching; serves as a protective barrier from the spread of infection or inflammation.- Layers: Fibrous(outer) and Serous (inner): parietal and visceral.- pericardial cavity between each layers; contains with film of serous fluid which lubricates membrane surface and allows easy movement.
|
|
|
Homeostatic imbalances of pericardium (2)
|
Pericarditis: pericardium inflammation.
Cardiac Tamponade: fluid build upon pericardial cavity; more than 120 cc of fluid cause stop the beating of the heart |
|
|
What are the 3 layers of the heart wall and how are they organized? What is the fibrous skeleton of the heart and what is its role?
|
Epicardium, Myocardium, and Endocardium.
Fibrous Cardiac Skeleton is a dense network formed by connective tissue fibers. |
|
|
What are the 3 main sulci of the heart? What is a sulcus?
|
-Coronary, anterior interventricular, and posterior interventricular sulcus.
- Sulcus is grooves on surface of heart containing coronary blood vessels and fat. |
|
|
What are major features of right atrium / roles? What is a septum? Which valve is here?
|
-Entryway; Receives blood returning to the heart.
-Septum separates the atria or each chambers. -Tricuspid valves |
|
|
What are major features of right ventricle / roles? What is Chordae tendinae? What valve?
|
-Discharging chambers; pumps blood into the pulmonary trunk to the lungs.
-Both serves as a guy-wire that anchor the valve flaps in their closed position. -Pulmonary semilunar valve |
|
|
What are major features of left atrium / roles? What valve?
|
-Receives blood from lungs - 4 pulmonary veins (2 right + 2 left).
-Bicuspid valve |
|
|
What are major features of left ventricle / roles? What valve?
|
-Ejects blood into aorta.
-Aortic semilunar valve |
|
|
Where is thickest myocardium and why?
|
left ventricle wall is the thickest to supply systemic circulation
|
|
|
What is coronary circulation? Anastomoses?
|
-Coronary circulation is blood supply to the heart., When the heart relaxes high pressure of blood in aorta pushes blood into coronary vessels
-anastomoses is connections between arteries supplying blood to the same region, provide alternate routes if one artery becomes occluded |
|
|
Major coronary arteries and their branches
|
Left coronary artery: circumflex branch- supplies left atrium and posterior left ventricle; anterior interventricular art.-supplies both ventricles
Right coronary artery: marginal branch-supplies lateral right ventricle; posterior interventricular art.-supplies apex and both posterior ventricles |
|
|
Major coronary veins and the sinus. Where does the sinus drain
into? |
Cardiac Veins: Great, middle, small and anterior.
-Collects wastes from cardiac muscle Drains into a large sinus on posterior surface of heart called the coronary sinus Coronary sinus empties into right atrium |
|
|
Homeostatic imbalances of the coronary arteries: MI, clot,
angina pectoris And general ways to treat them: angioplasty, CPR, transplants, artificial hearts. |
MI = myocardial infarction
death of area of heart muscle from lack of O2 replaced with scar tissue results depend on size & location of damage Blood clot use clot dissolving drugs streptokinase or t-PA & heparin Angina pectoris heart pain from ischemia of cardiac muscle |
|
|
What are some heart valve disorders and how are they repaired /replaced?
|
Stenosis is a narrowing of a heart valve which restricts blood flow.
Insufficiency or incompetence is a failure of a valve to close completely. -Stenosed valves may be repaired by balloon valvuloplasty, surgical repair, or valve replacement. |
|
|
What are some differences between cardiac / skeletal muscle? Main microscopic features of cardiac muscle? What is an intercalated disc?
|
Cardiac muscle has intercalated disk, binucleated, striated, and involuntary control. Skeletal muscle lacks intercalated disk,multinucleate, striated, voluntary, and has fibers.
Intercalated disk is specialized connection between myocardial cells containing gap junctions and desmosomes. |
|
|
What does ECG/EKG stand for? What does intrinsic mean? Auscultation?
|
-ECG/EKG- ELECTROCARDIOGRAPHY. -Independent, the ability of cardiac muscle to depolarize and contract. -Listen
|
|
|
How does cardiac muscle contraction differ from skeletal (know at least 3 ways). What is the role of gap junctions in cardiac muscle?
|
1.Nervous system not required to excite cardiac muscle: pacemakers present in heart will make their own action potentials; nervous system / hormones can modify contraction
2.The spontaneous action potential leads to Ca++ release from SR but also extracellular calcium required which leads to contraction 3.The action potential does spread to nearby cardiac muscles via gap junctions -Gap Junctions allows ion to pass from cell to cell, transmitting current across the entire heart. |
|
|
Why is there an intrinsic heart rhythm? What is autorhythmic? How do gap junctions play a role in the heart? What is the conduction system?
|
-So that it depolorizes and contracts in an orderly, sequential matter.
- Autorhythmic fibers: self-excitable cells that generate action potentials; these trigger cardiac myocytes to contract. These are the intrinsic pacemakers. - Gap junctions: Heart contracts as a single unit due to a traveling wave of depolarization across the entire organ. -Conduction system: The pacemakers and gap junctions are the route for the heart muscle depolarization wave; it does not move randomly, rather it travels in an coordinated pattern with organized timing to ensure that heart works as an effective pump. |
|
|
Where are the 5 main locations of the autorhythmic cells?
|
SA nodes (75PM), AV nodes (40-50PM), AV bundle (20-30), bundle branches, and purkinje fibers
|
|
|
What is an arrhythmia? Fibrillation? Defibrillation? Heart block?
|
Arrhythmia- initiates irregular heart beats; tachycardia- up HR, Brachycardia down HR.
Fibrillations- rapid and irregular or out-of-phase contractions: Defibrillation. Heart block- AV node damage interferes with the spreading of the signal to ventricles: need artificial pacemaker |
|
|
Which node normally sets the rhythm for the heart and what is the rhythm called? What is an artificial pacemaker? What is an ectopic focus? And what may cause it? What is another word for premature contraction of the heart muscles?
|
-SA node fires spontaneously 75 times per minute; hearts pacemaker; sinus rhythm.
-Artificial pacemaker needed if pace is too slow. -Ectopic focus is an abnormal pacemaker, may appear and take over the pacing of the heart rate or the AV node may become the pacemaker.; may result of too much caffeine or nicotine and generates impulses more quickly than the SA node.- premature contraction or EXTRASYSTOLE. |
|
|
What is an ECG and how is it different than a single action potential? Why do the leads need to be placed in several locations? How many are there typically in a clinical setting?
|
-A recording of the sum of all electrical changes that accompany each cardiac cycle (heartbeat) is called an electrocardiogram (ECG or EKG).
-The EKG is not an action potential, rather the composite record of action potentials produced by all the heart muscle fibers!!! The ECG helps to determine if the conduction pathway is abnormal, if the heart is enlarged, and if certain regions are damaged. -Leads that measure the voltage different part of the body. -12 lead placement provides spatial information in 3 directions. |
|
|
Know the 3 main peaks and 3 intervals of the ECG. How do they relate to the spread of the conductive current?
|
PEAKS
P wave--SA node to atrial depolarization QRS complex--ventricular depolarization T wave--ventricular repolarization; relax ventr INTERVALS P to Q interval--conduction time from atrial to ventricular excitation S-T segment--Ventricular myocardium depolarized: plateau phase of myocyte action potential Q-T interval--Beginning of ventricular depolarization til end of ventricular repolarization |
|
|
What is auscultation? What sounds does the heart make and where do they come from?
|
The act of listening to sounds within the body is called auscultation, and it is usually done with a stethoscope. The sound of a heartbeat comes primarily from the turbulence in blood flow caused by the closure of the valves, not from the contraction of the heart muscle (Figure 18.19).
The first heart sound (lubb)- closing of the atrioventricular valves soon after ventricular systole begins. The second heart sound (dupp)- closing of the semilunar valves close to the end of the ventricular systole. |
|
|
What is a heart murmur? Are all murmurs indicative of homeostatic imbalance?
|
A heart murmur is an abnormal sound that consists of a flow noise that is heard before, between, or after the lubb-dupp or that may mask the normal sounds entirely.
Not all murmurs are abnormal or symptomatic, but most indicate a valve disorder. |
|
|
Difference between diastole and systole;
|
The cycle consists of the systole (contraction) and diastole (relaxation) of both atria, rapidly followed by the systole and diastole of both ventricles.
|
|
|
What happens during ventricular filling (what stage is this: diastole? Systole?) What is EDV?
|
Pressure in the heart is low, blood returning from the circulatory is flowing passively through the atria and the open AV valves into the ventricles.
-rapid ventricular filling: as blood flows from full atria (80%)-diastasis: as blood flows from atria -atrial systole pushes final 20% blood into ventricle. -The amount of blood in the ventricle at the end of diastole is the End Diastolic Volume (EDV) -P Wave |
|
|
What is happening during ventricular systole? What is happening during isovolumetric contraction and ejection phases? What does this phase correspond to in the ECG?
|
Atria relax and ventricles begin to contract
Rising ventricular pressure results in closing of AV valves 2a) Isovolumetric contraction phase (all valves are closed) 2b) In ejection phase, ventricular pressure exceeds pressure in the large arteries, forcing the SL valves open -QRS wave |
|
|
What is isovolumetric relaxation and what phase (diastole / systole? ) What is dicrotic notch? How does cardiac cycle continue to next cycle? What is End systolic volume? Stroke volume?
|
Isovolumetric relaxation: early diastole
brief period when volume in ventricles does not change--as ventricles relax, pressure drops and SL valves close causes dicrotic notch (brief rise in aortic pressure) -While ventricles were in systole, atria in diastole but still filling with blood. In atrial pressure rises and AV valves will be forced open to repeat cycle. - (ESV): volume of blood remaining in each ventricle -(SV) the volume (mL) ejected per beat from each ventricle; EDV(120) – ESV(50) = SV(70mL/beat) |
|
|
How do the pressures vary throughout the cardiac cycle?
|
Blood pressure in aorta is 120mm Hg
Blood pressure in pulmonary trunk is 30mm Hg Differences in ventricle wall thickness allows heart to push the same amount of blood with more force from the left ventricle The volume of blood ejected from each ventricle is 70ml (stroke volume) |
|
|
Why is it important to move the same volume of blood from each ventricle?
|
See/read pg. 683
|
|
|
What is cardiac output? Cardiac reserve?
|
Cardiac output (CO) is the volume of blood ejected from the ventricles into the arteries each minute.
CO = SV X HR Cardiac reserve is the ratio between the maximum cardiac output a person can achieve and the cardiac output at rest. |
|
|
Name 4 things that regulate cardiac output?
|
Preload-affect of stretching
Contractility- contractile strength at any given muscle length; Inotropy-chemical influences Afterload-The pressure that must be overcome before a semilunar valve can open Hear Rate- |
|
|
Heart Beat regulation to regulate Cardiac Output
|
A. Autonomic Regulation; Sympathetic vs. parasympathetic
B. Chemical Regulation; Hormones and Ions C. Other factors; Age, gender, exercise, body temp |
|
|
What are the risk factors for CO homeostatic imbalances?
|
Risk factors associated with CO:
High blood cholesterol, high blood pressure, cigarette smoking, obesity & lack of regular exercise. Other factors include: diabetes mellitus, genetic predisposition, male gender, high blood levels of fibrinogen, left ventricular hypertrophy |
|
|
What is congestive heart failure? Causes? Left side failure is also known as? Right side?
|
Congestive heart failure is a chronic or acute state that results when the heart is not capable of supplying the oxygen demands of the body. Causes by
coronary atherosclerosis, hypertension, MI, valve disorders, congenital defects, dilated cardiomyopathy Left side heart failure-less effective pump so more blood remains in ventricle, heart is overstretched & even more blood remains, blood backs up into lungs as pulmonary edema, suffocation & lack of oxygen to the tissues Right side failure -fluid builds up in tissues as peripheral edema |
|
|
What is coronary artery disease? How may it be caused?
|
Heart muscle receiving insufficient blood supply
narrowing of vessels---atherosclerosis, artery spasm or clot atherosclerosis--smooth muscle & fatty deposits in walls of arteries Treatment drugs, bypass graft, angioplasty, stent |
|
|
From what embryonic germ layer does heart derive? When does it start beating?
|
The heart develops from mesoderm before the end of the third week of gestation. Heart starts pumping at Day 22.
|
|
|
What is a congenital heart defect? Know three and how they affect the heart.
|
A congenital defect is a defect that exists at birth, and usually before birth.
Some congenital defects are not serious or remain asymptomatic; others heal themselves. Ventricular septal defect- septum fails to form causes blood mixture between two ventricles. Coarctation of aorta- narrowing of aorta Tetralogy of Fallot- Multiple defects |
