20-Heart Flashcards
Layers of heart tissue - 3
Epicardium - fibroelastic tissue, adipose, blood vessels, lymph
Myocardium - cardiac muscle, 95%
Endocardium - inner, slippery to reduce friction, contiguous with large vessels (vena cava, aorta)
pericardium layers 1+2
Fibrous pericardium - anchors to mediastinum, dense irregular connective
Serous pericardium - parietal layer to Fibrous, visceral layer to heart, pericardial fluid
sulci - 3 + what in sulcus
Deep Coronary sulcus - divides atria from ventricles
Anterior interventricular sulcus - divides ventricles on front
Posterior interventricular sulcus - divides ventricles on back
contains fat and blood vessels
right atrium - blood from 3, anterior wall ridges, between atria, hole, valve to ventricle
blood from superior/inferior vena cava, coronary sinus
anterior wall muscle ridges pectinate muscles
separation is interatrial septum, fossa ovalis from foramen ovale
blood passes through tricuspid valve to get to right ventricle
circle is fossa ovalis adult, hole in fetus foramen ovale
Right Ventricle - valve attachments - 2, where blood goes and valve
tricuspid valve attaced to chordae tendineae attached to cone shaped papillary muscles. Tightens to prevent prolapse.
Blood goes through pulmonary valve (semilunar) to pulmonary trunk
trabeculae carneae ridged muscle fibers involved in conduction system
Left Atrium - blood from, valve
Blood from 4 pulmonary veins
valve to ventricle - bicuspid/mitral/left atrioventricular
Left Ventricle what valve to where - 2, shunt in infant
Aortic valve to aorta
Aorta to coronary arteries
Thickest muscular walls, forms apex of heart
ligamentum arteriosum adult, ductus arteriosus embryo
Coronary Arteries - 6
Right Coronary Artery Aorta to right atrium, divides into posterior interventricular and marginal branches
Posterior interventricular follows posterior interventricular sulcus, supplies ventricles
Marginal runs along right margin, supplies right ventricle
Left Coronary Artery to anterior interventricular and circumflex
Anterior interventricular supplies both ventricles
Circumflex in coronary sulcus supplies left ventricle, left atrium
Coronary Veins - 3
Coronary sinus - posterior, drains most of blood
Great Cardiac vein - anterior interventricular sulcus, drains areas supplied by left coronary
Middle Cardiac vein - posterior interventricular sulcus, drains areas supplied by posterior interventricular
Heart location - 3
Mediastinum
Apex rests on diaphragm
posterior flat surface is base
auricles
aside atrium
increase blood carrying capacity
pectinate muscles in both, right mostly
collateral circulation
multiple arteries can feed an area
Anastamesis
conduction system - 5 + rate
SA beats 100 per minute
AP goes down interatrial septum to AV node
Delay at AV node to allow blood to move to ventricle
AP to AV bundle (bundle of his), splits to left and right bundles, to apex
Purkinje fibers carry AP out to rest of ventricles
intercalated discs - 2
gap junctions - bridge AP, heart muscles all beat as one
desmosomes - hold fibers together
Action Potentials of heart - 3 parts, types of channels
Depolarization - fast voltage gated Na channel, sarcolemma
Plateau - slow voltage gated Ca channel, sarcolemma
Repolarization - voltage gated K channels
Energy production in Cardiac Muscle+enzyme
Aerobic - fatty acids (60%), glucose (30%), lactic acid, amino acids, ketone bodies (5%) - rest
Exercise - more lactic acid
Creatine Kinase - enzyme for ATP production. In blood means myocardial infarction
EKG - uses - 4
Heart is enlarged
Cause of chest pain
Conduction pathway normal/abnormal
If heart damaged in certain areas
EKG - 3 waves
P wave - Atrial depolarization
QRS complex - Ventricular depolarization
T wave - Ventricular repolarization
EKG - 3 intervals/segments
P-Q interval - Beginning of Atrial excitation to beginning of ventricular excitation
S-T segment - time ventricular fibers are depolarized
Q-T interval - Start Ventricular depolarization to End Repolarization
Preload - 3
Amount of stretch in ventricle before pump.
Like rubber band, more stretch, more forceful contraction. Frank-Starling law.
Also greater the preload, greater the End Diastolic Volume EDV.
Afterload
Pressure to overcome before ejecting blood from ventricles.
Phases of heart contraction/relaxation - 2
Systole - contraction
Diastole - relaxation
Heart Sounds - 4 + name
Auscultation
S1 - lubb - closure of AV valves just after ventricular systole begins
S2 - dubb - closure of SL valves at beginning of ventricular diastole
S3 - blood turbulence, rapid ventricular filling
S4 - turbulence during atrial systole
Cardiac output / reserve
output - volume of blood pumped per minute, either ventricle
reserve - diff between resting output and max output. typically 4x to 5x resting.
