cardiovascular system notes: the heartstaff.katyisd.org/sites/1401055/documents/b - notes - the...
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Cardiovascular System Notes:The Heart
The human heart creates enough pressure to squirt blood 30 feet.
Interesting Cardiovascular System Facts
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?
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)
Tunica externa /connective tissue (elastin) – tunica
media/smooth muscle – tunica intima/endothelium
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
1. Epicardium: outer portion
(visceral pericardium)
• 3 layers
• THE HEART WALL
EPICARDIUM
2. Myocardium: middle layer
consists of twisted cardiac
muscle
• THIS IS THE LAYER THAT
ACTUALLY CONTRACTSMYOCARDIUM
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
• receives blood from
pulmonary veins
• LEFT ATRIA
• 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
4. Aortic Semilunar Valve: between aorta
and left ventricle