The heart is a muscular organ roughly the size of a fist located behind the breastbone. It pumps blood through the cardiovascular system. The heart has four chambers - two upper atria and two lower ventricles. The right side receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it back out to the body. Valves between the chambers prevent backflow of blood. When the heart contracts, these valves open and close in sequence to ensure blood flows in one direction through the entire circulatory system.
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The Human Heart
2. BASICALLY
The heart is a muscular organ about the size of a fist, located
just behind and slightly left of the breastbone. The heart
pumps blood through the network of arteries and veins called
the cardiovascular system
ascular system.
expectation
Reality!!!
4. The apex (pointed end) points down and to the left. It is 5
inches (12 cm) long, 3.5 inches (8-9 cm) wide and 2.5
inches (6 cm) from front to back, and is roughly the size of
your fist.
The average weight of a female human heart is 9 ounces
and a male's heart is 10.5 ounces.
The heart comprises less than 0.5 percent of the total body
weight.
5. The heart has
Endocardium; 3 layers:
smooth inner lining.
Myocardium; middle
layer of the muscle.
Pericardium; fluid sac
call surrounding it.
6. 1) The right
atrium pumps the
blood to the right
ventricle from the
veins.
2) The right ventricle receives
blood from the right atrium and
pumps it to the lungs where it is
loaded with oxygen.
3) The left atrium
receives blood
from the lungs
and pumps it to
the left ventricle.
5) The blood is
collected from the
body and sent
back to the heart!
4) The left
ventricle pumps
oxygen rich blood
to the rest of the
body, the vigorous
contractions
create blood
pressure
8. Tricuspid
valve (exit
of right
atrium)
Aortic
Valve (exit
of left
ventricle)
Each
chamber has
a valve
preventing
backflow of
blood.
Mitral
Valve (exit
of left
atrium)
1) When each chamber
contracts, valve at its
exit opens!
2) When it is
finished
contracting, the
valve closes
preventing backflow
Pulmonary of blood
Valve (exit
of right
ventricle)
3) When the heart
muscle contracts,
blood is pumped
out of the heart.
4) Heart contracts in 2 stages;
1) Both atria contract at same
time pumping blood to
ventricle.
2) The ventricles contract
together to propel blood out of
heart, so the muscle relaxes
before the next beat and refills
10. PULMONARY ARTERY;
CARRY DEOXYGENATED
BLOOD FROM HEART TO THE
LUNGS.
BEGINS AT THE BASE OF THE
RIGHT VENTRICLE.
BRANCHES INTO RIGHT AND
LEFT ARTERY WHICH DELIVER
BLOOD TO THE
CORRESPONDING LUNG.
11. THE AORTA IS THE LARGEST
ARTERY IN THE HUMAN
BODY, IT ORIGIATES FROM
THE LEFT VENTRICLE AND
EXTENDS DOWN TO TE
ABDOMEN.
HERE IT BIFURCATES INTO
SMALLER ILLIAC
ARTERIES.
12. THE SUPERIOR VENA
CAVA IS LARGE IN
DIAMETER YET A
SHORTER VEIN THAT
CARRIES
DEOXYGENATED
BLOOD FROM THE
UPPER HALF OF THE
BODY TO THE RIGHT
ATRIUM OF THE
HEART
13. ALSO KNOWN AS
THE POSTERIOR
VENA CAVA.
LARGE VEIN
INFERIOR
VENA
CAVA
CARRIES DE
OXYGENATED BLOOD
FROM LOWER HALF
OF THE BODY TO THE
RIGHT ATRIUM