of the lungs, with as much precision as their expansion and contraction
in breathing permit. (See the cut.)
45. The apex of each lung rises into the neck behind the sternal end of
the clavicle and sterno-mastoid muscle as much as an inch and a half:
in females rather higher than in males (30). From the sternal ends of
the clavicles the lungs converge, so that their thin edges almost meet
in the mesial line on a level with the second costal cartilage. Thus
there is little or no lung behind the first bone of the sternum. From
the level of the second costal cartilage to the level of the fourth,
the margins of the lungs run parallel, or nearly so, close behind the
middle of the sternum: consequently their thin edges overlap the great
vessels and valves at the base of the heart.
Below the level of the fourth costal cartilage the margins of the
lungs diverge, but not in an equal degree. The margin of the right
corresponds with the direction of the cartilage of the sixth rib:
the margin of the left, being notched for the heart, runs behind the
cartilage of the fourth. A line drawn perpendicularly from the nipple
would find the lung margin about the lowest part of the sixth rib.
Laterally, _i.e._ in the axillary line, the lung margin comes down as
low as the eighth rib: posteriorly, _i.e._ in the dorsal or scapular
line, it descends as low as the tenth.
It should be remembered that, in a deep inspiration, the lung margins
descend about one inch and a half.
In children the lungs are separated in front by the thymus gland.
Allowance should be made for this. About the approach of puberty the
thymus disappears.
46. =Anterior mediastinum.=--The direction of the anterior mediastinum
is not straight down the middle of the sternum, but slants a little to
the left, owing to the position of the heart. The right pleural sac
generally encroaches a little upon the left, behind the middle of the
sternum. A needle introduced through the middle of the sternum opposite
the third or the fourth rib would go through the right pleura.
47. =Reflection of pleura.=--The reflection of the pleura from the wall
of the chest on to the diaphragm corresponds with a sloping line drawn
from the bottom of the sternum over the cartilages of the ribs down to
the lower border of the last rib.
Since the pleura lines the inside of the last rib, a musket ball or
other foreign body, loose in the pleural sac, and rolling on the
diaphragm, might fall to the lowest part of the sac, which would be
between the eleventh and twelfth ribs. The ball might be extracted
here. The chest might also be tapped here, but not with a trochar,
since a trochar would penetrate both layers of pleura, and go through
the diaphragm into the abdomen.
The operation should be done cautiously, by an incision beginning about
two inches from the spine, on the outer border of the ‘erector spinæ,’
on a level between the spines of the eleventh and twelfth dorsal
vertebræ. The intercostal artery will not be injured if the opening be
made below the middle of the space, which is very wide.[3]
_THE BACK._
48. =Median furrow.=--In a muscular man, a furrow, caused by the
prominence of the erector spinæ on each side, runs down the middle of
the back. The lower end of the furrow corresponds with the interval
between the spine of the last lumbar and that of the first sacral
vertebra.
49. =Spines of vertebræ.=--A little friction with the fingers down the
backbone will cause the spines of the vertebræ to be tipped with red,
so that they can be easily counted, and any deviation from the straight
line detected. Still it is worth remembering that the spine of the
third dorsal is on a level with the commencement of the spine of the
scapula--that the spine of the seventh dorsal is on a level with the
inferior angle of the scapula--that the spine of the last dorsal is on
a level with the head of the last rib.
=Division of the trachea.=--The division of the trachea is opposite the
spine of the third, in some cases the fourth, dorsal vertebra. In front
this division is on the level of the junction of the first with the
second bone of the sternum.
The root of the spine of the scapula is marked by a slight dimple
in the skin. This is on a level with the third intercostal space. A
stethoscope placed on the inner side of this dimple would cover the
bronchus, more especially the right, since it is nearer to the chest
wall.
Make a man lean forwards, with his arms folded across the chest; this
will make prominent the spines of the vertebræ. The lower border of the
trapezius will guide you to the spine of the twelfth dorsal vertebra.
50. The place where the kidney is most accessible to pressure is below
the last rib, on the outer edge of the erector spinæ.
51. The highest part of the ilium is about the level of the fourth
lumbar spine. The best incision for opening the descending colon is
in a slightly sloping line beginning at the outer edge of the erector
spinæ, midway between the crest of the ilium and the last rib, and
continued across the flank for three inches or more, according to the
amount of subcutaneous fat.
52. In the pit of the neck we can feel the trapezius and the ligamentum
nuchæ. By pressing deeply we detect the forked and prominent spine of
the second cervical vertebra.
53. The spines of the third, fourth, and fifth cervical vertebræ recede
from the surface to permit free extension of the neck, and cannot often
be felt. But the spines of the sixth and seventh (v. prominens) stand
out well.
54. Notice that most of the spines of the dorsal vertebræ, owing to
their obliquity, do not tally with the heads of their corresponding
ribs. Thus, the spine of the second dorsal corresponds with the head
of the third rib; the spine of the third dorsal with the head of the
fourth rib, and so on till we come to the eleventh and twelfth dorsal
vertebræ, which do tally with their corresponding ribs. All this,
however, is best seen in the skeleton.
55. The spines of the vertebræ may be useful as landmarks indicative
of the levels of important organs. I have therefore arranged them in a
tabular form, thus:--
TABULAR PLAN OF PARTS OPPOSITE THE SPINES OF THE VERTEBRÆ.
{ 5th. Cricoid cartilage. Œsophagus begins.
CERVICAL. { 7th. Apex of lung: higher in the female than in the
{ male. (30)
{ 1st.
{ 2nd.
{ 3rd. Aorta reaches spine. Apex of lower lobe of lung.
{ Angle of bifurcation of trachea. (49)
{ 4th. Aortic arch ends. Upper level of heart.
{ 5th.
{ 6th.
DORSAL. { 7th.
{ 8th. Lower level of heart. Central tendon of diaphragm.
{ 9th. Œsophagus and vena cava through diaphragm. Upper edge
of spleen.
{ 10th. Lower edge of lung. Liver comes to surface
posteriorly. Cardiac orifice of stomach.
{ 11th. Lower border of spleen. Renal capsule.
{ 12th. Lowest part of pleura. Aorta through diaphragm.
Pylorus.
{ 1st. Renal arteries. Pelvis of kidney. (83)
{ 2nd. Termination of spinal cord. Pancreas. Duodenum just
below. Receptaculum chyli.
LUMBAR. { 3rd. Umbilicus. Lower border of kidney.
{ 4th. Division of aorta. (65) Highest part of ilium.
{ 5th.
56. =Origins of the spinal nerves.=--It is useful to know opposite what
vertebræ the spinal nerves in the different regions arise from the
spinal cord. They arise as follows:--
The origins of the eight cervical nerves correspond to the interval
between the occiput and the sixth cervical spine.
The origins of the first six dorsal nerves correspond to the interval
between the sixth cervical and the fourth dorsal spines.
The origins of the six lower dorsal nerves correspond to the interval
between the fourth and the eleventh dorsal spines.
The origins of the five lumbar nerves correspond to the interval
between the eleventh and twelfth dorsal spines.
The origins of the five sacral nerves correspond to the spines of the
last dorsal and the first lumbar vertebræ.
57. =Movements of the spine.=--The movements of which the spine
is capable are threefold: 1. Flexion and extension; 2. Lateral
inclination; 3. Torsion. Flexion and extension are freest between the
third and the sixth cervical vertebræ, between the eleventh dorsal
and the second lumbar, and between the last lumbar and the sacrum.
This is well marked in severe cases of opisthotonos, where the body is
supported on the back of the head and heels.[4]
Still better may it be observed when a mountebank bends backwards, and
touches the ground with his head.
The lateral movement is freest in the neck and the loins.
The movement of torsion or rotation round its own axis may be proved by
the following experiment:--Seated upright, with the back and shoulders
well applied against the back of a chair, we can turn the head and neck
as far as 70°. Leaning forwards so as to let the dorsal and lumbar
vertebræ come into play, we can turn 30° more.
58. =Position and motions of scapula.=--There are a few points worthy
of observation about the scapula. It covers the ribs from the second to
the seventh inclusive. We can feel its superior angle covered by the
trapezius. The inferior angle is covered by the latissimus dorsi, which
keeps it well applied against the ribs in the strong and athletic; but
in weak and consumptive persons the lower angles of the scapulæ project
like wings--hence the term ‘scapulæ alatæ.’
A line drawn horizontally from the spine of the sixth dorsal vertebra
over the inferior angle of the scapula gives the upper border of the
latissimus dorsi. Another line drawn from the root of the spine of the
scapula to the spine of the last dorsal vertebra gives the lower border
of the trapezius, which stands a little in relief.
59. The sliding movement of the scapula on the chest can be properly
understood only on the living subject. It can move not only upwards
and downwards as in shrugging the shoulders--backwards and forwards
as in throwing back the shoulders--but it has a rotatory movement
round a movable centre. This rotation is seen while the arm is being
raised from the horizontal to the vertical position, and is effected
by the co-operation of the trapezius with the serratus magnus. The
glenoid cavity is thus made to look upwards, the inferior angle slides
forwards, and is well held under the latissimus dorsi.
60. For the medical examination of the back, the patient should sit
with the arms hanging between his thighs, to lower the scapulæ as much
as possible. In this position the spine of the scapula corresponds
(nearly) with the fissure between the upper and lower lobes of the
lung; the apex of the lower lobe being about the level of the third rib.
_THE ABDOMEN._
The student is assumed to be familiar with the conventional lines
dividing the abdomen into regions.
61. =Abdominal lines.=--The linea alba, or central line of the abdomen,
marks the union of the aponeuroses of the abdominal muscles. It runs
from the apex of the ensiform cartilage to the symphysis pubis. As this
line is the thinnest and least vascular part of the abdominal wall, we
make our incision along it in ovariotomy, and in the high operation
of lithotomy; in it, we tap the abdomen in ascites, and the distended
bladder in retention of urine.
The so-called ‘linea semilunaris,’ at the outer border of the sheath of
the rectus, corresponds with a line, drawn slightly curved (with the
concavity towards the linea alba), from the lowest part of the seventh
rib to the spine of the pubes. This line would be in an adult about
three inches from the umbilicus; but in an abdomen distended by dropsy
or other cause, the distance is increased in proportion.
It is important to know the position of the ‘lineæ transversæ,’ or
tendinous intersections across the rectus abdominis. There are rarely
any below the umbilicus, and generally three above it. The first is
about the level of the umbilicus. The second is about four inches
higher--that is, about the level of the lowest part of the tenth rib.
These are the principal lines, and they divide the upper part of each
rectus into two nearly quadrilateral portions, an upper and a lower:
of these, those on the right side are a trifle larger than on the
left. We see these muscular squares pretty plainly in some athletic
subjects. Much more frequently we see them, too much exaggerated, on
canvas and in marble. Artists are apt to exaggerate them, and make the
front of the belly too much like a chess-board. It is lucky for them
that all the world do not see with anatomical eyes.
A familiarity with the shape and position of these divisions of the
rectus is of importance, lest we should, in ignorance, make a mistake
in our diagnosis. A spasmodic contraction of one of these divisions,
particularly the upper, or a collection of matter within its sheath,
has been frequently mistaken for deep-seated abdominal disease.
In the erect position, the anterior superior spines of the ilia are a
little below the level of the promontory of the sacrum. The bifurcation
of the aorta is on about the level of the highest part of the crest of
the ilium.
62. =Umbilicus.=--The umbilicus is not midway between the ensiform
cartilage and the pubes, but rather nearer to the pubes. In all cases
it is situated above the centre of a man’s height. It is a vulgar error
to say that when a man lies with legs and arms outstretched, and a
circle is drawn round him, the umbilicus lies in the centre of it. This
central point is in most persons just above the pubes.
In very corpulent persons two deep transverse furrows run across the
abdomen. One runs across the navel and completely conceals it. The
other is lower down, just above the fat of the pubes. In tapping
the bladder above the pubes in such a case, the trochar should be
introduced where this line intersects the linea alba.
Although the position of the umbilicus varies a little in different
persons, as the abdomen is unusually protuberant or the reverse, still,
as a general rule, it is placed about the level of the body of the
third lumbar vertebra. Now, since the aorta divides a little below the
middle of the fourth lumbar, it follows that the best place to apply
pressure on this great vessel is one inch below the umbilicus, and
slightly to the left of it (65). That the aorta can, under favourable
circumstances, be compressed under chloroform sufficiently to cure
an aneurysm below it, is proved by recorded cases, and by none more
effectually than by a case related in the second volume of the ‘Reports
of St. Bartholomew’s Hospital.’
It may be asked, why not apply pressure on the aorta above the
umbilicus? The answer is, that the aorta above the umbilicus is farther
from the surface, and is, moreover, covered by important structures
upon which pressure would be dangerous.
63. =Parts behind linea alba.=--Let us next consider what viscera lie
immediately behind the linea alba. For two or three fingers’ breadth
below the ensiform cartilage there is the left lobe of the liver,
which here crosses the middle line. Below the edge of the liver comes
the stomach, more or less in contact with the linea alba, according
to its degree of distension. In extreme distension the stomach
pushes everything out of the way, and occupies all the room between
the liver and the umbilicus. When empty and contracted, it retreats
behind the liver, and lies flat in front of the pancreas at the back
of the abdomen; thus giving rise to the hollow termed the ‘pit of
the stomach.’ But as the stomach distends, it makes a considerable
fulness where there was a pit. The middle of the transverse colon lies
above the umbilicus, occupying space (vertically two or three inches)
according to its distension. Behind and below the umbilicus, supposing
the bladder contracted, are the small intestines, covered by the great
omentum.
64. =Peritoneum.=--The peritoneum is in contact with the linea alba
all the way down to the pubes, when the bladder is empty. But when
the bladder distends, it raises the peritoneum from the middle
line above the pubes; so that with a bladder distended half-way up
to the umbilicus, there is a space of nearly two inches above the
symphysis where the bladder may be tapped without risk of injury to
the peritoneum. For the same reason, we have space sufficient for the
successful performance of the high operation for stone. This fact in
anatomy must have been well understood by Jean de Dot, the smith at
Amsterdam, who, in the seventeenth century, cut himself in the linea
alba above the pubes, and took out of his bladder a stone as large as
a hen’s egg. The stone, the knife, and the portrait of the operator,
may be seen to this day in the museum at Leyden.
65. =Division of Aorta.=--The aorta generally divides at a point one
inch and a half below the umbilicus. A more reliable guide to this
division than the umbilicus, is a point (a very little to the left) of
the middle line about the level of the highest part of the crest of the
ilium. A line drawn with a slight curve outwards from this point to the
groin, where the pulsation of the common femoral can be distinctly felt
(rather nearer to the pubes than the ilium), gives the direction of the
common iliac and external iliac arteries. About the first two inches of
this line belong to the common iliac, the remainder to the external.
Slight pressure readily detects the pulsation of the external iliac
above ‘Poupart’s ligament.’
As a rule, the length of the common iliac is about two inches, but it
should be remembered there are frequent deviations. It may be between
three-quarters of an inch and three inches and a half long. These
varieties may arise either from a high division of the aorta, or a low
division of the common iliac, or both. It is impossible to ascertain
during life what is its length in a given instance, for there is no
necessary relation between its length and the height of the stature.
It is often short in tall men, and _vice versâ_. Anatomists generally
describe the right as a trifle longer than the left; but their average
length is pretty nearly the same.
66. Mr. Abernethy, who in the year 1796 first put a ligature round
the external iliac, made his incision in the line of the artery. But
the easiest and safest way to reach the vessel is by an incision
(recommended in the first instance by Sir Astley Cooper, and now
generally adopted), beginning just on the inner side of the artery, a
little above Poupart’s ligament, and continued upwards and outwards
a little beyond the spine of the ilium. The same incision extended
farther in the same direction would reach the common iliac.
67. =Bony prominences.=--The anterior superior spine of the ilium, the
spine of the pubes, and the line of Poupart’s ligament, are landmarks
with which every surgeon should be thoroughly familiar.
68. =Spine of ilium.=--The spine of the ilium is the spot from which we
measure the length of the lower extremity. It is a valuable landmark in
determining the nature of injuries to the pelvis and the hip. The thumb
easily feels the spine, even in fat persons. Its position with regard
to the trochanter major should be carefully examined. The best way to
do this is to place the thumbs firmly on the opposite spines, and to
grasp the trochanters with the fingers. Any abnormal position on one
side is thus easily ascertained with the sound side as a guide.
69. =Spine of pubes.=--The spine of the pubes is the best guide to the
external abdominal ring. It cannot easily be felt by placing the finger
directly over it, since it is generally covered by fat. To feel it
distinctly, we should push up the skin of the scrotum and get beneath
the subcutaneous fat. If there be any difficulty in finding it, abduct
the thigh, and the tense tendon of the adductor longus will lead up to
it.
The position of the spine of the pubes is appealed to as a means of
diagnosis in doubt between inguinal and femoral hernia. The spine lies
on the outer side of the neck of an inguinal hernia, on the inner side
of the neck of a femoral.
The spine of the pubes is nearly on the same horizontal line as the
upper part of the trochanter major. In this line, about one full
inch external to the spine, is the femoral ring. Here is the seat of
stricture in a femoral hernia.
70. =Poupart’s ligament, or crural arch.=--The line of Poupart’s
ligament (crural arch) is in most persons indicated by a slight
crescent-like furrow along the skin. It corresponds with a line drawn
not straight, but with a gentle curve downwards from the spine of
the ilium to the spine of the pubes. With the help of the preceding
landmarks it is easy to find the exact position of the external and
internal abdominal rings, and the direction of the inguinal canal.
71. =Abdominal rings.=--The external abdominal ring is situated
immediately above the spine of the pubes. It is an oval opening with
the long axis directed obliquely downwards and inwards. Though its size
varies a little in different persons, yet as a rule it will admit the
end of the little finger, so that we can tell by examination whether
it be free or otherwise. To ascertain this, the best way is to push up
the thin skin of the scrotum before the finger; then, by tracking the
spermatic cord, the finger readily glides over the crest of the pubes
and feels the sharp margins of the ring.
The position of the internal ring is about midway between the spine of
the ilium and the symphysis of the pubes, and about two-thirds of an
inch above Poupart’s ligament.
72. =Inguinal canal.=--The position of the external and internal
abdominal rings being ascertained, it is plain that the direction of
the inguinal canal must be obliquely downwards and inwards, and that
its length in a well-formed adult male is from one and a half to two
inches, according as we include the openings or not. In very young
children the canal is much shorter and less oblique, the inner ring
being behind the outer. With the growth of the pelvis in its transverse
direction, the anterior spines of the ilia become farther apart, and
thus draw the internal ring more and more away from (_i.e._ to the
outer side of) the external.
73. =Spermatic cord.=--The spermatic cord can be felt as it emerges
through the external ring, and its course can be tracked into the
scrotum. The vas deferens can be distinctly felt at the back of the
cord, and separated from its other component parts.
74. =Epigastric artery.=--The direction of the deep epigastric artery
corresponds with a line drawn from the inner border of the internal
ring up the middle of the rectus muscle, towards the chest.
In thin persons the absorbent glands which lie along Poupart’s ligament
can be distinctly felt. They are usually oval, with their long axes
parallel to the line of the ligament.
75. =Abdominal viscera.=--Now let us see how far we can make out
externally the position and size of the abdominal viscera.
To make this examination with anything like success, it is desirable to
relax the abdominal muscles. The man should be on his back, the head,
shoulders and thorax being well raised, to relax the recti muscles; and
the thighs bent on the abdomen, to relax the several fasciæ attached to
the crural arch. To induce complete relaxation, where a very careful
examination is desired, chloroform should be given.
In manipulating the abdomen we should not use the tips of the fingers.
This is sure to excite the contraction of the muscles. The flat hand
should be gently pressed upon it, and with an undulating movement.
76. It is well to bear in mind that the central tendon of the diaphragm
is about the level of the lower end of the sternum at its junction with
the seventh costal cartilage; that the right half of the diaphragm
rises to about the level of the fifth rib--that is, about an inch below
the nipple; that the left half does not rise quite so high. In tranquil
breathing the diaphragm descends about half an inch.
The position of the abdominal viscera varies, to a certain extent,
in different persons. In some of them, especially the stomach, their
position varies in the same person at different times.
Let us take, first, the largest of the abdominal viscera--the liver.