Surface anatomy pdf - Abdomen

Surface Anatomy

151

natomy

aphic

adiog

For a detailed discussion, see page 226.

natomy

face

Surface Landmarks of the Abdominal

The xiphoid process is the thin cartilaginous lower part

Wall

Xiphoid Process

of the sternum. It is easily palpated in the depression where

of the umbilical cord in the fetus.

position. It is a puckered scar and is the site of attachment

The umbilicus lies in the linea alba and is inconstant in

median groove (see Figs. 4.11 and 4.12).

abdominal wall and is represented on the surface by a slight

fusion of the aponeuroses of the muscles of the anterior

and lies in the midline (see Fig. 4.3). It is formed by the

extends from the symphysis pubis to the xiphoid process

The linea alba is a vertically running fibrous band that

to enter the spermatic cord at the upper end of the scrotum.

emerges from the tail and ascends medial to the epididymis

The vas deferens

and a narrow lower end, the

body,

head,

(see Fig. 4.21). It has an enlarged upper end called the

epididymis

rior to the testis is an elongated structure, the

and not tethered to the skin or subcutaneous tissue. Poste

(see Fig. 4.21). The testis should therefore lie free

vaginalis

anterior, and medial surfaces by the two layers of the

on each side is a firm ovoid body surrounded on its lateral,

testis

along the line of fusion. The

scrotal raphe,

called the

is indicated by the presence of a dark line in the midline,

ered with sparse hairs. The bilateral origin of the scrotum

matic cords. The skin of the scrotum is wrinkled and is cov

testes, the epididymides, and the lower ends of the sper

The scrotum is a pouch of skin and fascia containing the

uterus.

difficult to palpate; it transmits the round ligament of the

In the female, the superficial inguinal ring is smaller and

(see Figs. 4.5 and 4.21).

vas deferens

terior part called the

and note the presence of a firm cordlike structure in its pos

upper part of the scrotum between the finger and thumb

scrotum (see Fig. 4.8). Palpate the spermatic cord in the

descending over or medial to the pubic tubercle into the

can be felt emerging from the ring and

spermatic cord

the scrotum with the tip of the little finger. The soft tubu

can be felt by invaginating the skin of the upper part of

4.8, and 4.12). In the adult male, the margins of the ring

above and medial to the pubic tubercle (see Figs. 4.2, 4.3,

aponeurosis of the external oblique muscle and is situated

The superficial inguinal ring is a triangular aperture in the

the pubic tubercle.

spine and curves downward and medially, to be attached to

4.11). It is attached laterally to the anterior superior iliac

rosis of the external oblique muscle (see Figs. 4.2, 4.6, and

groin. It is the rolled-under inferior margin of the aponeu

The inguinal ligament lies beneath a skin crease in the

tubercle (see Fig. 4.32).

superior surface of the pubic bones medial to the pubic

is the name given to the ridge on the

pubic crest

wall. The

midline at the lower extremity of the anterior abdominal

4.11). It is felt as a solid structure beneath the skin in the

the midline between the bodies of the pubic bones (see Fig.

The symphysis pubis is the cartilaginous joint that lies in

rior surface of the pubis (see Figs. 4.3, 4.12, and 4.32).

may be identified as a small protuberance along the supe

The pubic tubercle is an important surface landmark. It

Pubic Tubercle

the body of the 5th lumbar vertebra.

of the crest (see Fig. 4.12). The tubercle lies at the level of

iliac spine, the outer margin projects to form the tubercle

About 2 in. (5 cm) posterior to the anterior superior

4th lumbar vertebra.

(Fig. 4.49). Its highest point lies opposite the body of the

posterior superior iliac spine

and 4.12) and behind at the

(see Figs. 4.11

anterior superior iliac spine

in front at the

The iliac crest can be felt along its entire length and ends

rib may be short and difficult to palpate.

lies opposite the body of the 3rd lumbar vertebra. The 12th

gin reaches its lowest level at the 10th costal cartilage, which

by the cartilages of the 11th and 12th ribs. The costal mar

8th, 9th, and 10th ribs (see Figs. 4.11 and 4.12) and behind

racic wall and is formed in front by the cartilages of the 7th,

The costal margin is the curved lower margin of the tho

thoracic vertebra.

of the sternum, and it lies opposite the body of the ninth

is identified by feeling the lower edge of the body

junction

xiphisternal

abdominal wall (see Figs. 4.11 and 4.12). The

the costal margins meet in the upper part of the anterior

Costal Margin

Iliac Crest

Symphysis Pubis

Inguinal Ligament

Superficial Inguinal Ring

lar

Scrotum

-
-

tunica

tail.

Linea Alba

Umbilicus

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CHAPTeR 4

4th lumbar vertebra. This is commonly used as a sur

on the iliac crests and lies on the level of the body of the

The intercristal plane passes across the highest points

vertebra.

(see Fig. 4.12). This plane lies at the level of the 3rd lumbar

costal margin on each side—that is, the 10th costal cartilage

The horizontal subcostal plane joins the lowest point of the

hila of the kidneys.

duodenojejunal junction, the neck of the pancreas, and the

This plane passes through the pylorus of the stomach, the

It lies at the level of the body of the 1st lumbar vertebra.

(linea semilunaris) crosses the costal margin (see Fig. 4.12).

point where the lateral margin of the rectus abdominis

of the ninth costal cartilages on the two sides—that is, the

The horizontal transpyloric plane passes through the tips

Transpyloric Plane

symphysis pubis.

point between the anterior superior iliac spine and the

Each vertical line (right and left) passes through the mid

Vertical Lines

cedures.

diseased structures or the performing of abdominal pro

monly used to facilitate the description of the location of

Vertical lines and horizontal planes (see Fig. 4.12) are com

stand out.

the rectus abdominis muscles so that their lateral edges

using the arms. To accomplish this, the patient contracts

on the back and raise the shoulders off the couch without

accentuate the semilunar lines, the patient is asked to lie

of the ninth costal cartilage (see Figs. 4.11 and 4.12). To

abdominis muscle and crosses the costal margin at the tip

The linea semilunaris is the lateral edge of the rectus

halfway between the two (see Fig. 4.11).

level of the tip of the xiphoid process, at the umbilicus, and

als, they can be palpated as transverse depressions at the

across the rectus abdominis muscle. In muscular individu

The tendinous intersections are three in number and run

Tendinous Intersections of the Rectus

the arms.

the shoulders while in the supine position without using

they can be made prominent by asking the patient to raise

alba (see Fig. 4.11) and run vertically in the abdominal wall;

The rectus abdominis muscles lie on either side of the linea

The Abdomen: Part I—The Abdominal Wall

Rectus Abdominis

Abdominis

Linea Semilunaris

Abdominal Lines and Planes

Subcostal Plane

Intercristal Plane

face

erforming a lumbar spinal tap (see

landmark when p

may just be felt (see Fig. 4.48).

midaxillary line. In infants, the lower pole of the spleen

adult it does not normally project forward in front of the

Its long axis corresponds to that of the 10th rib, and in the

under cover of the 9th, 10th, and 11th ribs (see Fig. 4.48).

The spleen is situated in the left upper quadrant and lies

margin (see Fig. 4.48).

of the right rectus abdominis muscle crosses the costal

right ninth costal cartilage—that is, where the lateral edge

The fundus of the gallbladder lies opposite the tip of the

contracts and pushes down the liver.

ily felt when the patient inspires deeply and the diaphragm

felt a fingerbreadth below the costal margin. It is most eas

palpable. In a thin adult, the lower edge of the liver may be

developed right rectus abdominis muscle, the liver is not

gin (see Fig. 4.48). In the adult who is obese or has a well-

extends one or two fingerbreadths below the costal mar

about the end of the third year, the lower margin of the liver

its bulk lies on the right side (Fig. 4.48). In infants, until

The liver lies under cover of the lower ribs, and most of

surface markings are of clinical value.

The following organs are more or less fixed, and their

of viscera.

and respiration have a profound influence on the position

variations in the same person at different times. Posture

abdominal viscera show individual variations as well as

It must be emphasized that the positions of most of the

Viscera

umbilicus and the area around the umbilicus, respectively.

indicate the area below the xiphoid process and above the

are loosely used to

periumbilical

epigastrium

terms

upper right, upper left, lower right, and lower left. The

sect at the umbilicus (see Fig. 4.12). The quadrants are the

rants by using a vertical and a horizontal line that inter

It is common practice to divide the abdomen into quad

lumbar vertebra.

the iliac crests (see Fig. 4.12) and lies at the level of the 5th

The horizontal intertubercular plane joins the tubercles on

page 704).

Intertubercular Plane

Abdominal Quadrants

-
-

and

Surface Landmarks of the Abdominal

Liver

Gallbladder

Spleen

Surface Anatomy

kidneys extend from the 12th thoracic spine to the 3rd lum

breadths from the midline (see Fig. 4.49). On the back, the

kidney lies on the transpyloric plane, about three finger

On the anterior abdominal wall, the hilum of each

ney, which is higher than the right kidney, is not palpable.

piratory movement of the diaphragm. The normal left kid

about 1 in. (2.5 cm) in a vertical direction during full res

poorly developed abdominal muscles. Each kidney moves

region at the end of deep inspiration in a person with

and the lower pole can be palpated in the right lumbar

kidney (because of the bulk of the right lobe of the liver),

The right kidney lies at a slightly lower level than the left

the body and tail lie above and to the left.

lies below and to the right, the neck lies on the plane, and

The pancreas lies across the transpyloric plane. The head

153

Pancreas

Kidneys

-
-

bar spine, and the hili are opposite the 1st lumbar

ebra

vert

(see Fig. 4.49).

tip of 9th

costal cartilage

liver

fundus of
gallbladder

linea semilunaris

margin of liver

lower pole of spleen

liver

ribs

FIGURE 4.48

Surface markings of the fundus of the gallbladder, spleen, and liver. In a young child, the lower margin of the

may just be felt at the end of deep inspiration.

normal liver and the lower pole of the normal spleen can be palpated. In a thin adult, the lower margin of the normal liver

154

CHAPTeR 4

fingerbreadths to the right of the midline.

The duodenum lies on the transpyloric plane about four

in the umbilical region or below.

has an extremely variable position

greater curvature

The

line joining the cardioesophageal junction and the pylorus.

lies on a curved

lesser curvature

right of the midline. The

lies on the transpyloric plane just to the

pylorus

The

10th thoracic vertebra).

(the esophagus pierces the diaphragm at the level of the

breadths below and to the left of the xiphisternal junction

lies about three finger

cardioesophageal junction

The

The Abdomen: Part I—The Abdominal Wall

Stomach

Duodenum (First Part)

transpyloric
plane

posterior supe rior

T12

lateral margin of
erector spinae muscle

iliac crest

iliac spine

12th rib

FIGURE 4.49

Surface anatomy of the kidneys on the posterior abdominal wall.

hilum of each kidney to the transpyloric plane.

Surface anatomy of the kidneys and ureters on the anterior abdominal wall. Note the relationship of the

Surface Anatomy

anterior superior iliac spine and the symphysis pubis.

oral artery. It can be located at a point halfway between the

the inguinal ligament to become continuous with the fem

The pulsations of this artery can be felt as it passes under

of the midline.

the upper part of the anterior abdominal wall just to the left

The pulsations of the aorta can be easily palpated through

the 4th lumbar vertebra—that is, on the intercristal plane.

below into the right and left common iliac arteries opposite

The aorta lies in the midline of the abdomen and bifurcates

above the symphysis pubis (see page 260).

through the lower part of the anterior abdominal wall

The full bladder and pregnant uterus can be palpated

and can be palpated through the anterior abdominal wall.

ing colon has a smaller diameter than the ascending colon

become continuous with the sigmoid colon. The descend

left lower quadrant, it curves medially and downward to

tal margin on the lateral side of the left vertical line. In the

The descending colon extends downward from the left cos

position is variable.

concavity directed upward. Because it has a mesentery, its

pying the umbilical region. It arches downward with its

The transverse colon extends across the abdomen, occu

Transverse Colon

the anterior abdominal wall.

under the right costal margin. It can be palpated through

the lateral side of the right vertical line and disappears

The ascending colon extends upward from the cecum on

appendix is variable.

(McBurney’s point). The position of the free end of the

joining the anterior superior iliac spine to the umbilicus

the appendix is situated one third of the way up the line,

The appendix lies in the right lower quadrant. The base of

nal wall.

percussed. It can be palpated through the anterior abdomi

often distended with gas and gives a resonant sound when

The cecum is situated in the right lower quadrant. It is

155

Cecum

Appendix

Ascending Colon

Descending Colon

Urinary Bladder and Pregnant Uterus

Aorta

External Iliac Artery

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