Download Heart - Dr Magrann

Heart
STRUCTURES TO KNOW ON THE HEART
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1. apex and base
2. right and left atrium
3. right and left ventricle
4. interventricular septum
5. mitral valve (bicuspid valve)
6. tricuspid valve
7. pulmonary semilunar valve
8. aortic semilunar valve
9. papillary muscles
10. chordae tendinae
11. SA node
12. AV node
13. superior vena cava
14. inferior vena cava
15. pulmonary trunk (branches into the right and left pulmonary arteries)
16. pulmonary arteries (right and left)
17. pulmonary vein
18. aorta
19. right and left coronary artery
20. coronary sinus
21. ductus arteriosis
22. foramen ovale  fossa ovale
23. ligamentum arteriosum
Layers of the Heart

Epicardium (outer layer of heart)




AKA visceral layer of serous pericardium
It’s the shiny surface on outside of heart
Myocardium (contains cardiac muscle)
Endocardium (lines the inside of heart)
Arteries and Veins

ARTERY


Carries blood AWAY from the heart.
VEIN

Carries blood TO the heart.
Base
Atrial
septum
Right atrium
Right
ventricle
Apex
Ventricular
septum
Left atrium
Left
ventricle
Apex
Blood Flow



Deoxygenated blood goes to the heart
via the superior and inferior vena cavae,
which empty into the right atria.
Blood goes from the right atria into the
right ventricle by going through the
tricuspid valve.
It then goes into the lungs to get
oxygen.
Blood Flow



Oxygenated blood returns to the heart via the
pulmonary veins and enters into the left atria.
It goes into the left ventricle by passing
through the bicuspid (mitral) valve. If this
valve is blocked, blood will get backed up into
the pulmonary circulation.
Blood goes from the left ventricle into the
aorta, where it is sent to the body.
Blood Flow


Because there is high pressure in the
ventricles, there are semilunar valves
between the ventricles and the great
arteries (pulmonary artery and aorta).
The heart sounds (lub-dub) are caused
from the vibrations that result from the
semilunar valves slamming shut.
Heart Valves

Bicuspid (Mitral) valve


Tricuspid valve


Between right atrium and right ventricle
Aortic semilunar valve


between left atrium and left ventricle
Between left ventricle and aorta
Pulmonary semilunar valve


Between right ventricle and pulmonary artery
NOTE: The semilunar valves are between the
ventricles and the great arteries
Heart Valves


To keep the valves from prolapsing
(turning inside out), they are tied down
by cords, called cordae tendonae.
The cordae tendonae are anchored to
papillary muscles embedded in the
myocardium.
Right atrium
Tricuspid
valve
Right
ventricle
Apex
Left atrium
Mitral
(bicuspid)
valve
Left
ventricle
Aortic
semilunar
valve
Mitral
(bicuspid)
valve
Trabeculae
carnae
Pectinate
muscles
Cordae
tendonae
Coronary Arteries



The heart itself needs oxygen, too.
Right and left coronary arteries come off the
aorta and circle the outside of the heart to
supply the heart tissue.
When they are clogged, they may need a
coronary bypass surgery.

The saphenous vein (from the leg) is the vessel
most often used to replaced the damaged
coronary artery.
Coronary Sinus

This is the largest of the coronary veins
that carry deoxygenated blood from the
heart tissue back to the right atrium.
Left coronary
artery
Heart Beat



The heart contracts because of
electrical impulses from the sinoatrial
node (SA node) and the atrioventricular
node (AV node).
The SA node is the pacemaker. It
signals the atria to contract.
The AV node causes the ventricles to
contract.
SA node
Right atrium
AV node
Bundle of His
Bundle branches
Purkinje fibers
Superior
vena
cavae
Aorta
Pulmonary
trunk
SA Node
AV Node
Right
Atrium
Left
Atrium
Cordae
tendonae
Interventricular
septum
Right
Ventricle
Left
Ventricle
Papillary
muscles
Trabeculae
carnae
Superior
vena
cavae
Aorta
Pulmonary
trunk
Tricuspid
valve
Right
Atrium
Left
Atrium
Bicuspid
(Mitral)
valve
Cordae
tendonae
Papillary
muscles
Aortic
semilunar
valve
Right
Ventricle
Left
Ventricle
Superior
vena
cavae
Pulmonary
trunk
Aorta
Right
coronary
artery
Right
Atrium
Left
Atrium
Left
coronary
artery
Posterior
view of heart
Trachea
Superior
vena
cavae
Aorta
Pulmonary
veins
Coronary
sinus
Left
Atrium
Right
Atrium
Inferior
vena
cavae
Left
Atrium
Right
Atrium
Pulmonary
semilunar
valve
Left
ventricle
(the wall is
thicker)
Right
ventricle
Fetal Heart


The fetus has no need to use its
pulmonary circulation since it gets
oxygen from the placenta.
Therefore, blood flows from the
pulmonary artery right back into the
aorta.
Fetal Heart

The fetus also has an opening between
the right and left atria so blood can be
sent to the body faster.
Fetal Heart

Foramen Ovale


An opening between the right and left atrium in a
fetus, allows fetal blood to bypass the lungs. At
birth, it should close, leaving a bit of fibrous tissue
there called the Fossa Ovalis.
Ductus Arteriosis

A connection in the fetus between the pulmonary
artery and the aorta. At birth, it should close,
leaving a bit of fibrous tissue there called the
Ligamentum arteriosum.
Heart problems in newborn
Fetal Circulation

Umbilical Vein


This is an example where a vein carries
oxygenated blood (in the fetus).
Umbilical Artery

This artery has a mixture of oxygenated
and deoxygenated blood (in the fetus).
Umbilical
cord
Placenta
Umbilical artery
(blue; carries
mixed blood)
Umbilical vein
(red; carries
oxygenated blood)
Arteries and Veins

ARTERY



Carries blood AWAY from the heart.
They USUALLY carry oxygen, but not
always.
VEIN


Carries blood TO the heart.
They USUALLY are not oxygenated, but
sometimes they are.
Blood Vessels



Arterial walls are thicker than venous
walls because they are under higher
pressure.
Arteries have more elastin than veins.
The saphenous vein is often used to
bypass a damaged coronary artery
during a coronary bypass surgery.
ARTERY
MEDIUM POWER
ARTERIOLE
HIGH POWER
VEIN
VENUOLE
CAPILLARY
HIGH POWER