Lincoln telegraph. [volume] (Bath, Me.) 1836-1846, 1841-05-27
ORIGINAL.
Organization and Formation Of the Human
Heart. Circulation and Composition of the



Organization aud Formation of the Human
EHo6o, &c.
Next to the brain and nervous system, there is
| no organ or class of organs which plays a more
important part in the manifestations of human
life, than the heart and blood-vessels. As the
heart is the first point in which vitality is eyin-
ced in the formation of a new being, so it is the
very last in which life is seen to exist. Perform
ing of the highest offices in the animal econ
omy, it is not strange that this organ is viewed
with stndious concern by those who seek infor-
nation in relation to the structure of the human
species; and from the influence which it posses
SEES in the phenomena of human life,-its organi-
cation and mechanism, we'll that of the en-
tire animal machine throughout man de-
sign in his creation, and acknowledges with trem-
bling nsignificance in the presence Of an All
wise Designer, thai he is indeed fearfllly and
wonderfully made.
The heart is hollow muscle, ofan irregular,
pyramidal shape, situate obliquely, and little
to the left side, IN the chest resting on the mid
ffby of its surfaces; suspended by its base
from the gre vessels; free and movable, in the
rest of its extent and surrounded by a membra-
nous bag, which is called by Anatomsts, the per-
icardium. The right side of the body of the heart
is thin and sharp; the left side is thick and
round. 1t is hollow within, and contains four
cavities two of which, with thinner and less
heshy walls receive the blood from the lungs and
the rest of the body, and pour it into two others,
n IL, 4o
the lungs and every part of the body. OF these
cavities, the former are called quricles, the latter
reahicles. The right auricle and right ventrcle
form the PWmonic, or right, or anterior heart j;
and the left auricle and ventrcle, the systemic,
left, or postcrior heart. In the adult, these are
totally distinct from each other, being separated
by partition tie Septun, Cords Into the right
aurcle, the venm cavm,-ascendlng and de-
scending,-and the coronary vein, open,-the
pulmonary artery arises from the right ventrlcle,
and carries the venous blood, which has been re-
turned to the right side of the heart from all parts
of the body, to the lungs,-there to undergo the
viyifying process or Decentralization consequent
upon its contact with atmospheric air, inspired
into the lungs during the act of respiration
This constitutes the pulmonc Giro! or the venous
circulation. From the lungs, the blood, which is
now arteria in its properties, passes through four
pulmonary veins which open into the left aur-
Gle, thence into the left ventrice, passes into the
aorta, or the parent trunk of the arerial system,
which arises from the left ventrcle, and thence
courses to every part OF the body for its growth
and pourshmept, constituting the systemic or ar
teriai circulation.
The mean weight Of the heart, in the adult,
from the twenty-ffth TO the sixteth year, is, ac-
cording to Bouillaud, from eight to nine ounces.
1t is covered, externally, by very thin, membra-
nous reflection from the pericardium. The mus
cular structure of which it is constituted is much
thicker in the walls of the venricles than in those
of the auricles. Its cavities lined by very
delicate membrane, which is continuous with the
inner membrane of the arteries regards the left
cavities and with that of the veins, regards
the right. The arteries for their subsistence,
arise from the commencement of the parent trunk
of the arteral system. 1t is plentltuly supplied
with nerves, through which it sympathizes with
every organ and part contained in the living bo-
80
less extent by various emotions of the mind
d" Good tidings maketh the heart leap with Joy
=" sorrow depresseth it, are old sayings; but
nevertheless true, we believe, as every one must
confess who has noticed the influence of the mind
upon the body.
When the ear is applied to the chest of healthy
individual, dull heightened sound is heard,
which is synonymous with the arterial pulse
This is instantly succeeded by a sharp, quick
sound, like that of the valve of bellows, or the
tapping of dog. There is then period of re-
pose. The first sound appears to be produced by
the contraction of the yentricles the second by
the rehux of the blood against the semlunar
valves, situate at the commencement of the pa
rent arterial trunk. These are what we call the
Sounds Of the heart. The Jeating or impulse Of
the heart against the particles of the chest, is main
ly caused, perhaps, by the expansive force of the
heart WHICH tends to project it forwards. 1t is
uncertain, however, whether the impulsion is
produced by the dilataton or the contraction of
the ventrlcle
The heart is the great agent in the circulation