Ministry of Health of Ukraine
BUKOVINIAN STATE MEDICAL UNIVERSITY
“APPROVED”
on methodical meeting of the Department of
Anatomy, Topographical anatomy and Operative
Surgery
“………”…………………….2008 р. (Protocol №……….)
The chief of department
professor ……………………….……Yu.T.Achtemiichuk
“………”…………………….2008 р.
METHODICAL GUIDELINES
for the 2nd-year foreign students of English-spoken groups of the Medical Faculty
(speciality “General medicine”)
for independent work during the preparation to practical studies
THE THEME OF STUDIES
“Topographical anatomy of inguinal region. Topographical anatomy and
operative surgery of the inguinal hernias”
MODULE I
Topographical Anatomy and Operative Surgery
of the Head, Neck, Thorax and Abdomen
Semantic module 3
“Topographical Anatomy and Operative Surgery of the Abdomen”
Chernivtsi – 2008
1. Actuality of theme:
The topographical anatomy and operative surgery of the abdomen are very
importance, because without the knowledge about peculiarities and variants of
structure, form, location and mutual location of abdominal anatomical structures,
their age-specific it is impossible to diagnose in a proper time and correctly and to
prescribe a necessary treatment to the patient. Surgeons usually pay much attention to
the topographo-anatomic basis of surgical operations on the abdomen.
2. Duration of studies: 2 working hours.
3. Objectives (concrete purposes):
To know the definition of regions of the abdomen.
To know classification of surgical operations on the abdomen.
To know the topographical anatomy and operative surgery of the organs of the
abdomenal cavity.
4. Basic knowledges, abilities, skills, that necessary for the study themes
(interdisciplinary integration):
The names of previous disciplines
1. Normal anatomy
2. Physiology
3. Biophysics
The got skills
To describe the structure and function of the
different organs of the human body, to determine
projectors and landmarks of the anatomical
structures. To understand the basic physical
principles of using medical equipment and
instruments.
5. Advices to the student.
5.1. Table of contents of the theme:
The Inguinal Region
The inguinal region is very important surgically because it is the site of inguinal hernias
("ruptures") in both sexes; however, they are much more common in males. The inguinal region is
an area of weakness in the anterior abdominal wall, especially in males, owing to the prenatal
penetration of the wall by the testis and spermatic cord.
The Inguinal Canal. This is an oblique passage, about 4 cm long in adults, through the
inferior part of the anterior abdominal wall. It runs inferomedially, just superior and parallel to the
medial half of the inguinal ligament. The inguinal canal has two walls (anterior and posterior), two
openings (one at each end called the superficial and deep inguinal rings), a roof (superior wall), and
a floor (inferior wall).
The anterior wall of the inguinal canal is formed mainly by the aponeurosis of the external
oblique muscle. It is reinforced laterally by fibers of the internal oblique muscle; sometimes by
those of the transversus abdominis muscle.
The posterior wall of the inguinal canal is formed throughout by the transversalis fascia,
which is reinforced medially by the conjoint tendon, the common tendon of the internal oblique and
transversus abdominis muscles.
The floor of the inguinal canal is formed by the superior surface of the inguinal ligament
and the lacunar ligament.
The roof of the inguinal canal is formed by arching fibers of the internal oblique and
transversus abdominis muscles. The inferior epigastric artery lies at the medial boundary of the
deep inguinal ring; hence, its pulsations form a useful landmark during surgery for determining the
location of this ring.
Owing to the obliquity of the inguinal canal, the deep and superficial inguinal rings do not
coincide. Consequently, increases in intra-abdominal pressure act on the deep inguinal ring, forcing
the posterior wall of the canal against the anterior wall.
This strengthens this weak part of the anterior abdominal wall. The inguinal canal has been
likened to an arcade of three arches formed by the three flat abdominal muscles. Contraction of the
external oblique muscle approximates the anterior wall of the canal (formed mainly by the
aponeurosis of the external oblique) to the posterior wall (formed mainly by the transversalis
fascia). Contraction of the internal oblique and transversus abdominis muscles makes them taut; as
a result, the roof of the canal descends and the passage is constricted. During standing, these
muscles continuously contract. During coughing and straining, the raised intra-abdominal pressure
threatens to force some of the abdominal contents through the canal, producing a hernia. However,
vigorous contraction of the arched fleshy fibers of the internal oblique and transverses abdominis
muscles "clamp down." The action is like a halfsphincter that helps to prevent herniation.
Immediately posterior to the superficial inguinal ring is the conjoint tendon; the rectus abdominis
muscle is posterior to the conjoint tendon. When intra-abdominal pressure rises, the flat muscles of
the abdomen contract, forcing the external oblique aponeurosis against the conjoint tendon, which
then pushes against the rectus abdominis muscle. Hence, the conjoint tendon and rectus abdominis
muscle reinforce the posterior surface of the superficial inguinal ring, tending to prevent herniation.
The Superficial Ring of the Inguinal Canal. Although it is called a ring, the superficial
(external) inguinal ring is a more or less triangular aperture (deficiency) in the aponeurosis of the
external oblique muscle.
The base of this triangle is formed by the pubic crest and its apex is directed superolaterally.
The sides of the triangle are formed by the medial and lateral crura (L. legs) of the superficial
inguinal ring. Emerging from the superficial inguinal ring is the spermatic cord in the male and the
round ligament of the uterus in the female. In addition, the ilioinguinal nerve makes its exit through
the ring to supply skin on the superomcdial aspect of the thigh. The central point of the superficial
inguinal ring is superior to the pubic tubercle.
The lateral crus of the superficial inguinal ring is formed by the part of the external oblique
aponeurosis that is attached to the pubic tubercle via the inguinal ligament. The spermatic cord rests
on the inferior part of this crus. The medial crus of the superficial inguinal ring is formed by the
part of this aponeurosis that diverges to attach to the pubic bone and pubic crest, medial to the pubic
tubercle. Intercrural fibers from the inguinal ligament arch superomedially across the superficial
inguinal ring. They prevent the crura from spreading apart.
The superficial inguinal ring is palpable just superior and lateral to the pubic tubercle. In
men it can be examined by invaginating the skin of the scrotum with the tip of a digit (often the
index finger), and probing gently superolaterally along the spermatic cord. If the ring is enlarged, it
may admit the digit without causing pain. In women and children, the dimensions of the superficial
inguinal ring are much less than in men and palpation of it is difficult. In male infants the
superficial inguinal ring does not normally admit the tip of a digit.
The Deep Ring of the Inguinal Canal. This slitlike opening in the transversalis fascia is
located just lateral to the inferior epigastric artery. This deep (internal) ring is immediately
superior to the midpoint of the inguinal ligament and medial to the origin of the transverses
abdominis muscle from the inguinal ligament. The deep inguinal ring is the opening of a fingerlike
diverticulum of the transversalis fascia. It formed prenatally when the processus vaginalis
evaginated ("pushed through") the transversalis fascia. The margins of the deep ring are not sharply
defined, as are those of the superficial ring. When the external oblique is reflected and the epigastric
vessels are displaced, it ceases to exist as a ring; however, from the internal aspect, a dimple in the
peritoneum often marks the site of the deep inguinal ring.
Descent of the Testes. To understand the inguinal canal, some knowledge of the migration
and descent of the testes is essential. The testes develop in the lumbar regions deep to the
transversalis fascia, between it and the peritoneum. They normally pass through the inguinal canals
into the scrotum just before birth. The site of the inguinal canal in the fetus is first indicated by the
gubernaculum, a ligament that extends from the testis through the anterior abdominal wall and
inserts into the internal surface of the scrotum. Later, a fingerlike outpouching or diverticulum of
peritoneum, called the processus vaginalis, follows the gubernaculum and evaginates the anterior
abdominal wall to form the inguinal canal. The processus vaginalis pushes extensions of the layers
of the anterior abdominal wall before it. In males these prolongations of the layers of the anterior
abdominal wall become the coverings of the spermatic cord. In both sexes the opening produced by
the processus vaginalis in the external oblique aponeurosis forms the superficial inguinal ring. The
testes usually enter the inguinal canals just before birth and pass inferomedially through them to
enter the scrotum. Normally the stalk of the processus vaginalis obliterates shortly afterbirth,
leaving only the part surrounding the testis, which becomes the tunica vaginalis. The scrotal
ligament is the adult derivative of the gubernaculum.
Maldescent of a testis (undescended testis or cryptorchidism) is a common abnormality. The
testes are undescended in about 3% of full-term and 30% of premature infants. Undescended testes
are usually located somewhere along the inguinal canal. Most undescended testes descend during
the first few weeks after birth.
Descent of the Ovaries. The ovaries also descend from their sites of origin on the posterior
abdominal wall to a point just inferior to the pelvic brim; however, they do not normally enter the
inguinal canals. The processus vaginalis normally obliterates completely and the gubernaculums
attaches to the uterus, where it is divided into the ligament of the ovary and the round ligament of
the uterus. The round ligament of the uterus passes through the inguinal canal and attaches to the
internal surface of the labium majus (homologous to half of the scrotum). Persistence of the
processus vaginalis in a female, called a canal of Nuck clinically, may result in an indirect inguinal
hernia. Cysts in the inguinal canal and labium majus may also develop from remnants of the
processus vaginalis.
Summary of the Inguinal Canal. The inguinal canal is an oblique passage through the
inferior part of the anterior abdominal wall. The chief protection of the inguinal canal is muscular.
Its main constituent is the spermatic cord in males and the round ligament of the uterus in females.
It contains the ilioinguinal nerve in both sexes. It has an opening at each end, the deep and
superficial inguinal rings. The deep ring is a slitlike opening in the transversalis fascia and the
superficial ring is a triangular opening in the aponeurosis of the external oblique. The inguinal canal
has two walls (anterior and posterior), a roof, and a floor. The anterior wall is formed mainly by the
aponeurosis of the external oblique muscle and is reinforced laterally by fibers of the internal
oblique. The posterior wall is formed mainly by the transversalis fascia and is reinforced medially
by the conjoint tendon. The floor is formed by the inguinal and lacunar ligaments. The roof is
composed of the arching fibers of the internal oblique and transversus abdominis muscles.
1.
2.
3.
4.
5.
6.
7.
8.
5.2. Theoretical questions to studies:
The inguinal region.
The layer structure of the inguinal region.
The nerve and blood supplay of the inguinal region.
Fascias of the inguinal region.
Surgical anatomy of the inguinal hernias.
Principles of surgical treatment of the direct inguinal hernias.
Principles of surgical treatment of the indirect inguinal hernias.
Principles of surgical treatment of the congenital inguinal hernias.
9. Principles of surgical treatment of the strangulated hernias.
10.Principles of surgical treatment of the sliding hernias.
5.3. Materials for self-control:
1.
Diffuse pain referred to the epigastric region and radiating circumferentially around the chest
is the result of afferent fibers that travel via which of the following nerves?
A
B
C
D
E
2.
Greater splanchnic
Intercostal
Phrenic
Vagus
None of the above
In the patient described, the subsequent localization of the pain in the right hypochondriac
region is the result of inflammatory stimulation of fibers that are extensions of which of the
following nerves?
A
B
C
D
E
Greater splanchnic
Intercostal
Phrenic
Vagus
None of the above
3.
The patient receives a general anesthetic in preparation for a cholecystectomy. A right
subcostal incision is made, which begins near the xiphoid process, runs along and immediately
beneath the costal margin to the anterior axillary line, and transects the rectus abdominis
muscle and rectus sheath.
At the level of the transpyloric plane, the anterior wall of the sheath of the rectus
abdominis muscle receives contributions from the
A aponeuroses of the internal and external oblique muscles
B aponeuroses of the transversus abdominis and internal oblique muscles
C aponeuroses of the transversus abdominis and internal and external oblique muscles
D transversalis fascia
E transversalis fascia and aponeu-rosis of the transversus abdominis muscle
4.
At this level of incision, liga-tion of the superior epigastric artery probably will result in little,
if any, necrosis of the rectus abdominis muscle because the superior epigastric artery
anastomoses with the
A
B
C
D
E
5.
deep circumflex iliac artery
inferior epigastric artery
intercostal arteries
internal thoracic artery
musculophrenic artery
Exploration of the peritoneal cavity disclosed a distended gallbladder. It is located
A between the left and caudate lobes of the liver
B between the right and quadrate lobes of the liver
C in the falciform ligament
D in the lesser omentum
E in the right anterior leaf of the coronary ligament
6.
Numerous stones could be palpated. A finger was inserted into the omental foramen (of
Winslow), and the common bile duct was palpated for stones. Structures that bound the
omental foramen include all the following EXCEPT the
A
B
C
D
E
7.
caudate lobe of the liver
common bile duct
hepatic vein
inferior vena cava
superior part of the duodenum
Before closure of the incision, it is felt that a drain should be left in place in the abdominal
cavity so that any leakage of bile from the sutured stump or from inadvertent injury to the duct
system can be detected. This drain would most advantageously be located in the
A
B
C
D
E
omental bursa
pelvic cavity
pouch of Morison
right paracolic gutter
right subphrenic recess
Literature
1. Snell R.S. Clinical Anatomy for medical students. – Lippincott Williams &
Wilkins, 2000. – 898 p.
2. Skandalakis J.E., Skandalakis P.N., Skandalakis L.J. Surgical Anatomy and
Technique. – Springer, 1995. – 674 p.
3. Netter F.H. Atlas of human anatomy. – Ciba-Geigy Co., 1994. – 514 p.
4. Ellis H. Clinical Anatomy Arevision and applied anatomy for clinical
students. – Blackwell publishing, 2006. – 439 p.