Lymphatics and Nerves on the posterior abdominal wall pdf - Abdomen

222

CHAPTER 5

together.

tally arranged ganglia, the 1st and 2nd often being fused

The sympathetic trunk possesses four or five segmen

the left border of the aorta.

lies close to

left sympathetic trunk

inferior vena cava; the

lies behind the right border of the

right sympathetic trunk

vis below by passing behind the common iliac vessels. The

the medial arcuate ligament and gains entrance to the pel

vertebrae (Fig. 5.78). It enters the abdomen from behind

border of the psoas muscle on the bodies of the lumbar

the sympathetic trunk. It runs downward along the medial

above with the thoracic and below with the pelvic parts of

The abdominal part of the sympathetic trunk is continuous

Sympathetic Trunk (Abdominal Part)

tion are summarized in Table 5.1.

The branches of the lumbar plexus and their distribu

within the scrotum.

cremaster muscle and the drawing upward of the testis

of the thigh in the male results in reflex contraction of the

in which stimulation of the skin

cremasteric reflex,

the thigh (see page 450). It is the nervous pathway involved

which supplies a small area of the skin of

femoral branch,

the spermatic cord and supplies the cremaster muscle, and

which enters

genital branch,

the muscle and divides into a

anterior surface of the psoas. It runs downward in front of

(L1 and 2) emerges on the

genitofemoral nerve

The

sacrum and joins the 1st sacral nerve.

plexus (see page 255). It descends anterior to the ala of the

takes part in the formation of the sacral

lumbosacral trunk

4th lumbar root of the

and in the thigh see page 465.) The

(For a description of its course in the pelvis see page 455

by passing through the obturator foramen into the thigh.

and behind the common iliac vessels. It leaves the pelvis

and 4) crosses the pelvic brim in front of the sacroiliac joint

(L2, 3,

obturator nerve

psoas at the brim of the pelvis. The

lumbosacral trunk emerge from the medial border of the

The obturator nerve and the 4th lumbar root of the

men, it supplies the iliacus muscle.

to the femoral vessels and the femoral sheath. In the abdo

enters the thigh behind the inguinal ligament and lateral

and laterally between the psoas and the iliacus muscles and

the largest branch of the lumbar plexus. It runs downward

(L2, 3, and 4) is

femoral nerve

surface of the thigh. The

ment (see page 450). It supplies the skin over the lateral

enters the thigh behind the lateral end of the inguinal liga

crosses the iliac fossa in front of the iliacus muscle and

The Abdomen: Part II—The Abdominal Cavity

in the

inferior vena cava

cisterna chyli

right lumbar trunk

inferior mesenteric nodes

rectum

bladder

internal iliac nodes

external iliac nodes

common iliac nodes

lateral aortic
(para-aortic) nodes

left lumbar trunk

superior mesenteric nodes

celiac nodes

intestinal trunk

FIGURE 5.76

Lymph vessels and nodes on the posterior abdominal wall.

Basic Anatomy

223

subcostal nerve

iliohypogastric nerve

ilioinguinal nerve

genitofemoral nerve

lateral cutaneous

nerve of the thigh

femoral nerve

obturator nerve

to lumbosacral trunk

T12

FIGURE 5.77

Lumbar plexus of nerves.

of the medial side of the leg and foot; articular branches to hip and knee joints

Iliacus, pectineus, sartorius, quadriceps femoris muscles, and intermediate cutaneous

Cremaster muscle in scrotum in male; skin over anterior surface of thigh; nervous pathway for

skin of upper medial aspect of thigh; root of penis and scrotum in the male; mons pubis and

External oblique, internal oblique, transversus abdominis muscles of anterior abdominal wall;

Branches

Distribution

Iliohypogastric nerve

skin over lower anterior abdominal wall and buttock

Ilioinguinal nerve

labia majora in the female

Lateral cutaneous nerve of the thigh

Skin of anterior and lateral surfaces of the thigh

Genitofemoral nerve (L1, 2)

cremasteric reflex

Femoral nerve (L2, 3, 4)

branches to the skin of the anterior surface of the thigh and by saphenous branch to the skin

Obturator nerve (L2, 3, 4)

Gracilis, adductor brevis, adductor longus, obturator externus, pectineus, adductor magnus

(adductor portion), and skin on medial surface of thigh; articular branches to hip and knee

joints

Segmental branches

Quadratus lumborum and psoas muscles

Branches of the Lumbar Plexus and their Distribution

T A B L E 5 . 1

responding lumbar spinal nerve. A gray ramus contains

join each ganglion to a cor

Gray rami communicantes

nerve fibers.

contains preganglionic nerve fibers and afferent sensory

to the first two lumbar spinal nerves. A white ramus

join the first two ganglia

White rami communicantes

Branches

■

medial arcuate
ligament

sympathetic
trunk

aorta

aortic opening in
diaphragm

celiac plexus

superior mesenteric
plexus

renal plexus

aortic plexus

inferior mesenteric
plexus

hypogastric plexus

FIGURE 5.78

Aorta and related sympathetic plexuses.

receive fibers from splanchnic nerves and the vagus.)

abdominal aorta and its branches. (These plexuses also

Fibers pass medially to the sympathetic plexuses on the

cles of the skin (see Fig. 1.4).

to the blood vessels, sweat glands, and arrector pili mus

are distributed through the branches of the spinal nerves

postganglionic nerve fibers. The postganglionic fibers

■

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CHAPTER 5

from the sacral parasympathetic.

enteric plexus is similar but receives parasympathetic fibers

branches of the corresponding arteries. The inferior mes

than the celiac plexus. They are distributed along the

The renal and superior mesenteric plexuses are smaller

the branches of the artery.

distribution. Parasympathetic vagal fibers also accompany

the branches of the celiac artery and follow them to their

sympathetic fibers). Postganglionic branches accompany

the greater and lesser splanchnic nerves (preganglionic

rounds the origin of the celiac artery. The ganglia receive

connected together by a large network of fibers that sur

celiac ganglia

The celiac plexus consists mainly of two

respectively.

inferior mesenteric

superior mesenteric plexus,

celiac plexus, renal plexus,

mesenteric arteries form the

gins of the celiac, renal, superior mesenteric, and inferior

Regional concentrations of this plexus around the ori

around the abdominal part of the aorta (Fig. 5.78).

aortic plexus,

ent fibers form a plexus of nerves, the

preganglionic parasympathetic fibers, and visceral affer

Preganglionic and postganglionic sympathetic fibers,

(Fig. 5.78).

hypogastric plexus

superior

they form a large bundle of fibers called the

branches from sympathetic nerves in front of the aorta,

mon iliac vessels into the pelvis, where, together with

Fibers pass downward and medially in front of the com

The Abdomen: Part II—The Abdominal Cavity

■

Aortic Plexuses

and

plexus,

Lumbar Sympathectomy

ticipate in reflex activity. Reflex sweating, salivation, nausea,

nal obstruction as in intestinal obstruction, in the passage of a

cera later move laterally as development proceeds, taking their

line structures and receive a bilateral nerve supply; many vis

probably because the viscera develop embryologically as mid

neum is chemically irritated, produces the same symptoms and

is inflamed. Any movement of that inflamed peritoneum, even

by the same nerves, it is not surprising to find cutaneous

Intercostal nerves

from the abdomen reach the central nervous system in the fol

skin, fascia, muscles, and parietal peritoneum. It can be severe

physician. This section provides an anatomic basis for the differ

the limb as branches of these nerves. Additional postganglionic

supply the vessels of the lower limb leave the spinal cord from

Lumbar sympathectomy is performed mainly to produce a vaso-

dilatation of the arteries of the lower limb in patients with vaso-

spastic disorders. The preganglionic sympathetic fibers that

segments T11 to L2. They synapse in the lumbar and sacral gan-

glia of the sympathetic trunks. The postganglionic fibers join the

lumbar and sacral nerves and are distributed to the vessels of

fibers pass directly from the lumbar ganglia to the common and

external iliac arteries, but they follow the latter artery only down

as far as the inguinal ligament. In the male, a bilateral lumbar

sympathectomy may be followed by loss of ejaculatory power,

but erection is not impaired.

Abdominal Pain

Abdominal pain is one of the most important problems facing the

ent forms of abdominal pain found in clinical practice.

Three distinct forms of pain exist: somatic, visceral, and

referred pain.

Somatic Abdominal Pain

Somatic abdominal pain in the abdominal wall can arise from the

and precisely localized. When the origin is on one side of the

midline, the pain is also lateralized. The somatic pain impulses

lowing segmental spinal nerves:

■

Central part of the diaphragm: Phrenic nerve (C3, 4, and 5)

■

Peripheral part of the diaphragm:

(T7 to 11)

■

Anterior abdominal wall: Thoracic nerves (T7 to 12) and the

1st lumbar nerve

■

Pelvic wall: Obturator nerve (L2, 3, and 4)

The inflamed parietal peritoneum is extremely sensitive, and

because the full thickness of the abdominal wall is innervated

hypersensitivity (hyperesthesia) and tenderness. Local reflexes

involving the same nerves bring about a protective phenomenon

in which the abdominal muscles increase in tone. This increased

tone or rigidity, sometimes called guarding, is an attempt to rest

and localize the inflammatory process.

Rebound tenderness occurs when the parietal peritoneum

when that movement is elicited by removing the examining hand

from a site distant from the inflamed peritoneum, brings about

tenderness.

Examples of acute, severe, localized pain originating in the

parietal peritoneum are seen in the later stages of appendicitis.

Cutaneous hyperesthesia, tenderness, and muscular spasm or

rigidity occur in the lower right quadrant of the anterior abdomi-

nal wall. A perforated peptic ulcer, in which the parietal perito-

signs but involves the right upper and lower quadrants.

Visceral Abdominal Pain

Visceral abdominal pain arises in abdominal organs, visceral

peritoneum, and the mesenteries. The causes of visceral pain

include stretching of a viscus or mesentery, distention of a hol-

low viscus, impaired blood supply (ischemia) to a viscus, and

chemical damage (e.g., acid gastric juice) to a viscus or its cov-

ering peritoneum. Pain arising from an abdominal viscus is dull

and poorly localized. Visceral pain is referred to the midline,

nerve supply with them.

Colic is a form of visceral pain produced by the violent

contraction of smooth muscle; it is commonly caused by lumi-

gallstone in the biliary ducts, or in the passage of a stone in the

ureters.

Many visceral afferent fibers that enter the spinal cord par-

vomiting, and increased heart rate may accompany visceral

pain.

C L I N I C A L N O T E S

(continued)