The Cardiovascular
System
The
cardiovascular system
consists
of two components
which
are the heart and the
blood
vessels.
The
heart pumps blood
so
that it flows to tissue
capillaries
and lung capillaries.
The
blood vessels are what
the
blood flows through.
The Heart
The heart is
located in the thoracic cavity
between the
lungs within the mediastinum.
It is a hollow,
cone-shaped, muscular organ
about the size
of a fist. As the heart pumps the
blood through
the pulmonary and systematic
vessels, it
performs these functions:
- keeps oxygen-poor blood separate
from oxygen-rich blood
- keeps the blood flowing in one
direction
- creates blood pressure, which moves
the blood through the circuits
- regulates the blood supply based on
the current needs of the body
The Wall Coverings of the Heart
Pericardium: two-layered serous membrane which
encloses the heart
Epicardium: outer surface of the heart
Myocardium: thickest part of the heart wall and is
made up of cardiac muscle
Parietal
Pericardium: serious layer
that acts as a wall
Fibrous
Pericardium: a layer of
fibrous connective tissue
Chambers of the Heart
Right Atrium
Recieves oxygen-poor blood from three veins: the
superior vena cava, the coronary sinus, and the
inferior vena cavity
Left Atrium
Receives oxygen-rich blood from four
pulmonary veins
Right Ventricle
The cusps of the tricuspid valve are connected
to fibrous cords,called the chordae tendineae
Left Ventricle
Forms the apex of the heart
Coronary Circuit
Two coronary arteries,
termed the left and right coronary arteries, branch
from the aorta just
beyond the
aortic semilunar valve.
Each
of these arteries
branches and
then rebranches, until
the heart
is encircled by small arterial
blood vessels. Some of
these
join so that there are
several
routes to reach any
particular capillary bed
in
the heart. Alternate
routes are
helpful if an
obstruction should
occur along the path of blood
reaching cardiac muscle cells.
Arteries and
Arterioles
Arteries transport
blood away from the heart. They have thick strong walls composed of three
layers: The tunica interna is
an endothelium layer with a basement membrane. The tunica media is a thick middle layer of smooth muscle
and elastic fibers. The tunica externa is an outer connective tissue layer composed principally of
elastic and collagen fibers.
á Secondhand smoke can damage your
cardiovascular system. It can damage it buy only being around smoke for a short
time.
á There are many diseases that you can get
if your system is not taken care of such as: Tricuspid atresia, Rheumatic
fever, Myocarditis, high blood pressure, low blood pressure, etc.
á You cannot take some medications because
they could damage your cardiovascular system, and cause a heart attack.
á You need to take care of your heart, and
your cholesterol. If your cholesterol is not taken care of properly, then it
puts you at risk for many infections, and maybe even a heart attack.
á You can get heart attacks if you do not
take care of your cardiovascular system properly.