Cardiovascular System
Cardiovascular System
• Two divisions
Cardiovascular System
• Two divisions: pulmonary
Cardiovascular System
• Two divisions: pulmonary &
systemic
Cardiovascular System
• Pulmonary Division
–Blood flows from heart
Cardiovascular System
• Pulmonary Division
–Blood flows from heart to
alveolar capillaries
Cardiovascular System
• Pulmonary Division
–Blood flows from heart to
alveolar capillaries and back
to heart
Cardiovascular System
• Systemic Division
Cardiovascular System
• Systemic Division
– Blood flows from heart
Cardiovascular System
• Systemic Division
– Blood flows from heart to all
tissue capillaries
Cardiovascular System
• Systemic Division
– Blood flows from heart to all
tissue capillaries (except
alveolar capillaries)
Cardiovascular System
• Systemic Division
– Blood flows from heart to all
tissue capillaries (except
alveolar capillaries) and back
to heart
• Pulmonary arteries carry blood:
• Pulmonary arteries carry blood:
High in O2, low in CO2
• Pulmonary arteries carry blood:
High in O2, low in CO2
Low in O2 high in CO2
• Heart
• Heart
– Location
• Heart
– Location: mediastinum
• Heart
– Location: mediastinum
• Heart
– Location: mediastinum
– Size?
• Pericardium
• Pericardium: protective sac
surrounding the heart
• Pericardium: protective sac
surrounding the heart
• Pericardium: protective sac
surrounding the heart
–Visceral
pericardium
• Pericardium: protective sac
surrounding the heart
–Visceral
pericardium
– Parietal
pericardium
• Pericardium: protective sac
surrounding the heart
–Visceral
pericardium
– Parietal
pericardium
• Layers of the heart wall
• Layers of the heart wall
– endocardium
• Layers of the heart wall
– endocardium
– myocardium
• Layers of the heart wall
– endocardium
– myocardium
• Layers of the heart wall
– endocardium
– myocardium
– epicardium
• Layers of the heart wall
– endocardium
– myocardium
– epicardium (same as the
visceral pericardium)
• Chambers of the heart
• Chambers of the heart
– Receiving chambers:
• Chambers of the heart
– Receiving chambers: atria
• Chambers of the heart
– Receiving chambers: atria
(singular:
• Chambers of the heart
– Receiving chambers: atria
(singular: atrium)
• Chambers of the heart
– Receiving chambers: atria
(singular: atrium)
• Chambers of the heart
– Receiving chambers: atria
(singular: atrium)
–Pumping chambers:
ventricles
• Right ventricle
• Right ventricle: pump for
the pulmonary circulation
• Right ventricle: pump for
the pulmonary circulation
• Left ventricle
• Right ventricle: pump for
the pulmonary circulation
• Left ventricle: pump for
the systemic circulation
• “Great Vessels” of the Heart
– Aorta
– Pulmonary Trunk
Aorta Pulmonary veins
LPA
Superior
RPA
vena cava Pulmonary
trunk
Inferior
vena cava
• Heart valves
• Heart valves
• Heart valves: ensure one-way
flow of blood through heart
– Semilunar valves
– Semilunar valves
• pulmonary semilunar
– Semilunar valves
• pulmonary semilunar
• aortic semilunar
• Atrio-ventricular (AV) valves
• Atrio-ventricular (AV) valves
• tricuspid
• Atrio-ventricular (AV) valves
• tricuspid
• bicuspid
• Atrio-ventricular (AV) valves
• tricuspid
• bicuspid (mitral)
• Atrio-ventricular (AV) valves
• tricuspid
• bicuspid (mitral)
Associated with papillary
muscles
• Atrio-ventricular (AV) valves
• tricuspid
• bicuspid (mitral)
Associated with papillary
muscles and chordae
tendinae
• Skeleton of the heart
– set of 4 fibrous rings near base
of heart
• Skeleton of the heart, con’t.
– provides rigidity to prevent the
dilation of valves
– provides a point of attachment
for valves
• Skeleton of the heart, con’t.
– electrically isolates the atria
from the ventricles.
•The A-V bundle (“bundle of
His”) is the only electrical
connection between the atria
and the ventricles
• Path of Blood Flow Through
the Heart
http://www.innerbody.com/ani
m/heart.html
• Heart Sounds
–1st sound (“lub”)
• closing of the AV valves
– 2nd sound (“dup”)
• closing of the semilunar
valves
• Heart Sounds
–1st sound (“lub”)
• closing of the AV valves
– 2nd sound (“dup”)
• closing of the semilunar
valves
Conduction System of the Heart
Sinoatrial node
Atrioventricular node
AV bundle
Bundle branches
Purkinje fibers
• Blood Vessels
1. Arteries
2. Arterioles
3. Capillaries
4. Venules
5. Veins
• All blood vessels are lined with
endothelium
1. Arteries
• Carry blood away from
the heart
• Subject to the highest
blood pressure
1. Arteries
• Carry blood away from
the heart
• Subject to the highest
blood pressure
1. Arteries
• Carry blood away from
the heart
• Subject to the highest
blood pressure
• Located deep
– Structure of
Arteries
• Tunica interna
• Tunica media
• Tunica externa
• Types of arteries
– Elastic arteries
• Contain elastic fibers in the
tunica media and interna
•Largest arteries
• Types of arteries
– Muscular arteries
• Little elasticity
• Abundant smooth
muscle in tunica
media
2. Arterioles
• < 1mm in diameter
• Endothelium and smooth
muscle
2. Arterioles
• < 1mm in diameter
• Endothelium and smooth
muscle
2. Arterioles
• < 1mm in diameter
• Endothelium and smooth
muscle
• Metarterioles regulate flow
of blood into capillaries
2. Arterioles
• < 1mm in diameter
• Endothelium and smooth
muscle
• Metarterioles regulate flow
of blood into capillaries
• Help regulate blood
pressure
3. Capillaries
• Sites of exchange
exchange between blood
and tissue cells in
systemic caps
exchange between blood
and air in pulmonary caps
• Very permeable
4. Veins
• Return blood back
towards heart
• Smallest veins: venules
• Veins have 3 layers like
arteries
• Differences between arteries
and veins
– thinner
– larger diameter
– located both deep and
superficial
– veins have valves
Distribution of Blood
• Coronary Circulation
– Blood flow to and from the
myocardial capillaries
• Some vessels of the coronary
circuit
– Right coronary artery
– Left coronary artery
• circumflex
• anterior interventricular
(also: LAD)
– Coronary sinus
• Hepatic Portal Circulation
• Features of fetal heart
– Foramen ovale
– Ductus arteriosus
• Other features of fetal
circulation
– Umbilical arteries and veins
– Ductus venosus
• Changes in fetal circulation
after birth
– foramen ovale closes
– ductus arteriosus closes
Coronary Artery Disease
• Degenerative changes in
coronary arteries
• Often associated with arterial
plaques
•