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Cardiovascular System Notes: The Heart. Interesting Cardiovascular System Facts. The human heart creates enough pressure to squirt blood 30 feet. Review. What are the 3 parts of the cardiovascular system?. heart – blood – blood vessels. What do arteries do?.
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Cardiovascular System Notes: The Heart
Interesting Cardiovascular System Facts The human heart creates enough pressure to squirt blood 30 feet.
Review What are the 3 parts of the cardiovascular system? heart – blood – blood vessels What do arteries do? Take blood AWAY from the heart What are the 3 layers of an artery? Tunica externa /connective tissue (elastin) – tunica media/smooth muscle – tunica intima/endothelium What do veins do? Bring blood TOWARD the heart What do veins have that arteries don’t? VALVES – (veins & arteries both have the same layers except the muscular layer is smaller)
What exchanges material between blood and the body’s cells? CAPILLARIES How big are they? microscopic in size
NOTES – THE HEART • Location: • cavity between the lungs, 2/3 left of midsagittal • roughly the size of a fist
Heart Anatomy • PERICARDIUM • outer membrane of the heart • 2 layers 1. Parietal pericardium: external (outer) layer 2. Visceral pericardium (epicardium): part of the heart wall
Functions: • protection – physical barrier • anchors heart to other structures • provides lubrication to reduce friction – allows the heart to beat easily
THE HEART WALL • 3 layers 1. Epicardium: outer portion (visceral pericardium) EPICARDIUM
2. Myocardium: middle layer consists of twisted cardiac muscle • THIS IS THE LAYER THAT ACTUALLY CONTRACTS MYOCARDIUM
3. Endocardium: inner layer made of epithelial tissue ENDOCARDIUM
HEART CHAMBERS • 4 chambers • Atrium (left/right atria) • divided by the INTERATRIAL SEPTUM • Function of Atria: receives blood from veins (pig heart)
RIGHT ATRIA • receives blood from superior & inferior vena cava • blood that’s been used • oxygen poor – high in CO2
LEFT ATRIA • receives blood from pulmonary veins • coming from lungs • rich in oxygen
Ventricles (left/right) • muscular pumps – divided by INTERVENTRICULAR SEPTUM (pig heart)
RIGHT VENTRICLE • receives blood from the right atria (O2 poor) • pumps blood to the lungs through the PULMONARY ARTERIES
LEFT VENTRICLE • receives blood (O2 rich) from the left atrium • pumps blood to the body through the AORTA
Systemic Circulation • heart – lungs – heart – body – heart
HEART VALVES (4) • allow for “one way” circulation • 2 Atrioventricular Valves (AV valves) 1. Tricuspid Valve: between right atria and right ventricle
2. Bicuspid or Mitral Valve: between left atria and left ventricle • heavier & stronger of the two
CHORDAE TENDINAE and papillary muscles stop valves from being folded backwards CHORDAE TENDINAE
3. Pulmonary Semilunar Valve: between the pulmonary artery and right ventricle