The heart is protected by rib cage locate between two lungs made of cardiac muscle protected by...
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Transcript of The heart is protected by rib cage locate between two lungs made of cardiac muscle protected by...
The heart is protected by rib cageThe heart is protected by rib cage
• locate between two lungs
• made of cardiac muscle
• protected by pericardium and rib cage
contracts and relaxes continuously to
provide (pumping force)
The mammalian heartThe mammalian heartHeartHeart
Heart – External View
Blood vessel
CardiacMuscle
Coronary artery and
vein
Vertical section of the HeartVertical section of the Heart
Left auricle
Left ventricle
Right auricle
Right ventricle
bicuspidvalve
Valve – prevent back flow of blood from
……………… to ……………..
Arteries
VeinsVeins
To lungsTo body
deoxygenated blood oxygenated blood
Pulmonary arteryAorta
Pulmonary veinsVena
cava
septumtricuspid valve
Semi-lunar valves
Oxygenated blood
Higher oxygen concentration
Lower carbon dioxide
concentration
Deoxygenated blood
Lower oxygen
concentration
Higher carbon dioxide
concentration
Full of Oxygen
Full of carbon dioxide
The cardiac cycleThe cardiac cycle (the sequence of events that takes place in one heart beat)
Auricle
Ventricle
0 0.2 0.4 0.6 0.8s
The heart beats as the cardiac muscles in its wall contracts (systole) and relaxes (diastole).
Auricle
Ventricle
0 0.2 0.4 0.6 0.8s
Auricular systole (0 –0.1s)
contraction of the two auricles, squeezing blood into the ventriclesAV valves (open), semi-lunar valves (close)
Auricle
Ventricle
0 0.2 0.4 0.6 0.8s
Ventricular systole (0.1 –0.4s)
contraction of the two ventricles, forcing blood out of the ventricles into the arteries AV valves (close), semi-lunar valves (open)
Auricle
Ventricle
0 0.2 0.4 0.6 0.8s
Diastole ( 0.4 - 0.8s )
all four chambers relax, allowing blood to flow into the auricles again.AV valves (open), semi-lunar valves (close)
Changes in blood pressure in the heart during one cardiac cycle.
bicuspid valve close
P(V) < P (A)P(V) > P (A)
bicuspid valve open
Heart beat rate = 60 / 0.8 = 75 beats / min
1st heat sound
Heart attackHeart attack
Fatty substances in blood
cover the inner wall of arteries
Plaque is formed and the
arteries become narrower
This reduce the amount of
blood flowing
Normal arteryNormal arteryArtery with fatty depositsArtery with fatty deposits
Formation of blood clotFormation of blood clot
fatty substances
blood flow restricted
(artery blocked by blood clot)
heartheart
Heart attackHeart attack
Same parts of heart muscle get
too little nutrients and oxygen
Heart beat is upset
HEART ATTACK
if coronary artery is blocked
damaged heart muscle