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Side ASide B
The study of the heart
The heart beats about
100,000 times a day or 35 milion beats a year
Porpels blood through appr.
120,00 km of vessels
Two- thirds of the heart lies to the
left of the midline
Where does the heart lie
Shape and size of heart
Holoow, cone-shaped, about the size of a closed fist
the pointed end on the diaphragm that is directed anterior, inferior, and to the left
broader, superior, and directed posterior and to the right
Surface projection is the outlined shape of an organ on the surface of the body Anterior...
Seperates the two ventricles
Pericadium- Two layers
membrane (sac) that surrounds and protects the heart, it has two layersFibrous pericadriumSerous...
superficial layer, tough, inelastic, prevents overstretching, provides protection, and...
deeper layer, thin; (i) parietal layer - fused to the fibrous pericardium (ii) visceral...
external layer, composed of mesothelium and connective tissue
between the two layers) is filled with pericardial fluid which reduces friction
middle layer, muscular pumping layer, 95% of the heart wall
inner layer, consists of a layer of endothelium covering connective tissue, continuous with...
inflammation of the endocardium
Cardiac Muscle Characteristics
Intercalated discs Desmosomes Gap junctions Sarcoplasmic reticulum
4 chambers of the heart
Two superior Chambers- right and left artiaTwo inferior chambers right and left ventricles...
right atrium and right ventricle, moves deoxygenated blood through the lungs
left atrium and left ventricle, pumps oxygenated blood to all systems of the body
Three major grooves Sulci
Coronay SulcusAnterior Interventricular SuclusPosterior Interventricular suclus
- encircles most of heart, demarcates the atria from the ventricles
Anterior Interventricular Suclus
marks the external boundary between right and left ventricles
Posterior Interventricular suclus
marks the external boundary between ventricles on the posterior surface
Right Atrium- Receives deoxygenated blood from three veins
Superior Vena CavaInferoir Vena CavaCoronary SInus
Superior Vena Cava (SVC)
- drains blood from parts of the body superior to the heart
Inferior Vena Cava (IVC)
brings blood from all parts of the body inferior to the diaphragm
receives blood from most of the vessels draining the wall of the heart
Anteroir wall that has interal muscular ridges
Interatrial septum (wall)
Seperates the atria
oval depression on the septum, remnant of the foramen ovale, a hole between the chambers...
Blood flows from the right atrium into the right ventricle through
the tricuspid valve (or right atrioventricular valve)
Forms most of the anterior surface of the heart
Inner surface lined with ridges
Chordae tenineae attach the
Tricuspid valve cusps to the papillary muscles
The blood passes through the ____ on its way to the lungs
The blood continues through the _____ which divides into the right and left ___...
pulmonary trunk, pulmonary arteries
Forms most of the base of the heart Pulmonary veins carry oxygenated blood (two from...
Bicuspid valve also called
mitral valve or the left atrioventricular valve
Thickest part of the heart Contains trabeculae carneae as well as papillary muscles...
The __ and ______ arteries branch from the _____ to supply the walls of the...
Right, left coronary artieries, ascenfing aorta
The rest of the blood passes into the arch of the aorta and ____ (consisting of ___ aorta...
Descending aorta, thoracic aorta and abdimonal aorta
The ____ , during fetal life, shunted blood from the pulmonary trunk into the aorta...
ductus arteriosus, ligamentum
Myocardial Thickness and Function The atria
thin-walled as they deliver blood under less pressure
Myocardial Thickness and Function- The ventricles
have thick walls since they pump blood at a higher pressure and over greater distances The...
Myocardial Thickness and Function
The left ventricle is thicker because it pumps under higher pressure and over a greater...
Fibrous Skeleton of the Heart
Dense connective tissue (NOT BONE) embedded in the walls of the heart Consists primarily...
Prevents overstretching of the valves as blood passes through them
1. right atrioventricular fibrous ring 2. left atrioventricular fibrous ring 3....
The four heart valves prevent
blackflow of blood in the heart ater blood passes through them
Atrioventricular (AV) valves
tricuspid valve between the right atrium and the right ventricle bicuspid (mitral)...
Two Semilunar (SL) vavles each having three cusps
Allow ejection of blood from the ventricles into aorta and pulmonary trunk Prevent...
Pulmonary valve between
right ventricle and pulmonary trunk
Aortic valve between
left ventricle and aorta
The hear pumps blood into two circuits arranged in series
Systematic circulationPulmonary Circulation
left side of heart receives oxygenated blood from the lungs Pumps this blood into the...
the right ventricle pumps blood into the pulmonary trunk which branches into the pulmonary...
Two Coronary artieries
Left and Right coronary artery
Left coronary artery
Anterior interventricular Circumflex branch
Right coronary artery
Posterior interventricular Marginal branch
Three coronary veins
Great cardica veinAnterior cardiac veinMiddle cardiac vein
Great cardiac vein
follows the course of the anterior interventricular artery and then the circumflex artery...
Anterior Cardiac vein
joins with the small cardiac vein to empty into the coronary sinus
Middle Cardiac Vein
empties into the coronary sinus
Anastomoses are connections between parallel arteries or veins Coronary sinus is a...
Cardiac Conduction System
Autorhythmic cells Pacemaker Conduction system
AS nodes fires
spontaneoulsy 90-100 times per minute
AV node firs
at 4-50 times per minute
If both AV and SA nodes are suppressed fibers in verntricles by themselves fire
only 20-40 times per minute
Artificial pacemakers needed
if pace is too slow
Extra beats forming at other sites caffine and nicotine increases activity
Electrocardiogram-ECG or EKG
Action potentials of all active cells can be detected and recorded
P to Q interval
Conduction time from atrial to ventricular excitation
Cardiac Cycle (Heartbeat
Consists of all the events associated with one heartbeat Normally the atria contract...
the contraction phase of a heart chamber
the relaxation phase of a heart chamber
Cardiac Cycle-major phases
At 75 beats/min, one cycle requires 0.8 sec. systole (contraction) and diastole (relaxation)...
End diastolic volume (EDV
volume in ventricle at end of diastole, about 130ml
End systolic volume (ESV)
volume in ventricle at end of systole, about 60ml
Stroke volume (SV)
the volume ejected per beat from each ventricle, about 70ml SV = EDV - ESV
Blood pressure in aorta is
122 mm Hg
Blood pressue in pulmonary trunk is
30 mm Hg
Differences in ventricle wall thickness allows heart to push the same amount of blood...
Amount of blood pushed into aorta or pulmonary trunk by ventricle Determined by stroke...
CO = SV x HR
at 70ml stroke volume & 75 beat/min----5 and 1/4 liters/min entire blood supply...
Cardiac reserve is maximum output/output at rest
average is 4-5 while athlete is 7-8
due to blood turbulence caused by closing of the AV valves
Second sound dupp S2
due to blood turbulence cause by closing of the semilunar valves
The sounds are best heard over
the chest at areas slightly away from the actual location of the valves
Risk factors for heart disease
Risk factors in heart disease: high blood cholesterol level high blood pressure cigarette...
Plasma Lipids and Heart Disease
Risk factor for developing heart disease is high blood cholesterol level. promotes...
Most lipids are transported as lipoproteins
low-density lipoproteins (LDLs) high-density lipoproteins (HDLs) very low-density...
remove excess cholesterol from circulation
are associated with the formation of fatty plaques
contribute to increased fatty plaque formation
There are two sources of cholesterol in the body:
in foods we ingest formed by liver (genetic predisposition)
Desirable Levels of Blood Cholesterol for Adults
TC (total cholesterol) under 200 mg/dl LDL under 130 mg/dl HDL over 40 mg/dl Normally,...
Coronary Artery disease
Heart muscle receiving insufficient blood supply narrowing of vessels---atherosclerosis,...