Gut Book 1: Abdominal Wall & Inguinal Region

Question 1

Abdominopelvic cavity

Answer 1

extends from the thoracoabdominal diaphragm above to the pelvic diaphragm below

Question 2

Abdominal wall

Answer 2

bones, fascia and muscles which enclose the cylinder-like abdominal cavity and serve to mobilize the abdomen during trunk rotation and compression of contents during defecation and parturition while at the same time protect the abdominal contents.

Question 3

Abdominal wall components (osseous, fascial and muscular)

Answer 3

Osseous: ribs 7-12, lumbar vertebrae 1-5, pelvis

Fascia: anterior- rectus sheath. Posterior- thoracolumbar fascia

Muscular: external and internal abdominal obliques, transversus abdominis, rectus abdominis, pyramidalis, quadratus lumborum, psoas major and minor

Question 4

Superficial landmarks of the abdominal wall and inguinal region

Answer 4

xiphoid process (TV 10)
costal margin
linea alba
umbilicus (LV 3-4 interspace)
linea transversae (tendinous intersections)
linea semilunaris
pubic symphysis
pubic tubercle
inguinal ligament
anterior superior iliac spine (ASIS)
crest of ilium

Question 5

Superficial fascia of abdomen

Answer 5

Fatty layer (camper's)
Membranous layer (Scarpa's)-- best differentiated below the level of the navel, it has definite attachments to the iliac crest, fascia lata below the inguinal ligament, pubic tubercle, pubic symphysis, perineal boundaries of the urogenital triangle

Question 6

Clinical correlation of the abdominal scrotal opening

Answer 6

formed by the weak attachment of the membranous layer to the pubic bone between the tubercle and symphysis, represents a potential path for extravasated fluid in the scrotum to ascend into the abdominal wall. However, due to the previously mentioned attachments, fluid remains in the flanks but does not progress into the lower limbs.

Question 7

Specializations of the membranous layer (scarpa’s) of the superfiscial fascia

Answer 7

Fundiform ligament

Tunica dartos scroti

Question 8

Fundiform ligament

Answer 8

robust development of membranous connective tissue which extends from the lower linea alba and passes lateral to the penis to end in the scrotal septum; provides support for the scrotum and testes

Question 9

Tunica dartos scroti

Answer 9

continuation of the fatty and membranous layers of superficial fascia into the scrotum as a single layer containing areolar tissue and SMOOTH MUSCLE, responsible for wrinkling of the scrotal skin

Question 10

Muscles of the abdominal wall, organized into 3 groups

Answer 10

Anterior: rectus abdominis, pyramidalis
Anterolateral: external and internal obliques, transversus abdominis
Posterior: psoas major and minor, quadratus lumborum

Question 11

clinical correlation: surgery and the fiber directions of abdominal wall musculature

Answer 11

The fiber direction of the anterolateral and anterior abdominal wall musculature is arranged so that successive layers assume a noncongruent orientation, viz., vertical, horizontal and oblique directions. During surgery this arrangement is preserved by splitting muscles parallel to their fiber direction on a per layer basis. Muscular fibers are never cut perpendicular to their fiber direction because they will scar, not only across the muscle fibers, but successive layers will adhere to one another impairing normal movements, making them painful. Whenever possible, abdominal incisions are placed on the mid-line (linea alba) where only fascial/ tendinous tissue will be incised.

Question 12

External abdominal oblique (O, I, A, N)

Answer 12

O: Outer surface of lower eight ribs interdigitating with serratus anterior and latissimus dorsi muscles.

I: Anterior 1/2 of the iliac crest (vertical fibers from last two ribs); remaining fibers descend obliquely downward toward the midline and via the external abdominal oblique aponeurosis attach to the linea alba from xiphoid process to pubic symphysis.

A: Both sides acting cause flexion of the vertebral column and pelvis as well as abdominal compression in defecation, parturition and forced expiration; one side acting causes lateral flexion of the trunk with rotation to the OPPOSITE side.

N: intercostal nerves 7-11, subcostal n., iliohypogastric n.

Question 13

external abdominal oblique aponeurosis

Answer 13

= the modified tendon of insertion of the external oblique muscle. It forms the inguinal ligament, the outermost layer of the rectus sheath and with its opposite counterpart participates in forming the linea alba.

Question 14

Internal abdominal oblique (O, I, A, N)

Answer 14

O: posterior layer of thoracolumbar fascia, anterior 2/3 of iliac crest, lateral 2/3 of inguinal ligament

I: inferior borders of the lower four or five ribs, linea alba from xiphoid to pubic symphysis via the internal oblique aponeurosis

A: both sides acting cause flexion of the vertebral column and pelvis as well as abdominal compression in defecation, parturition and forced expiration; one side acting causes lateral flexion of the trunk with rotation to the SAME side.

N: intercostal nerves 8-11, subcostal n., iliohypogastric n., ilioinguinal n.

Question 15

Specializations of the internal abdominal oblique

Answer 15

Cremaster muscle- muscular layer of the spermatic cord derived from the internal abdominal oblique

conjoint tendon (falx inguinalis)- the combined fascias of the IAO and transversus abdominis

Question 16

Transversus abdominis (O, I, A, N)

Answer 16

O: undersurface of the lower six ribs (interdigitated with the muscular slips of the diaphragm), thoracolumbar fascia, anterior 3/4 of iliac crest, lateral portion of inguinal ligament

I: linea alba from xiphoid to symphysis pubis via transversus abdominis aponeurosis

A: contraction causes compression of the abdomen and its contents

N: intercostal nerves 8-11, subcostal n., iliohypogastric n., ilioinguinal n.

Question 17

Rectus abdominis (O, I, A, N)

Answer 17

O: anterior surface of the pubis

I: cartilages of the 5th, 6th and 7th ribs; fibers may attach to the lateral anterior surface of the xiphoid process

A: flexes the vertebral column and pelvis, assists in compression of the abdomen

N: intercostal nerves 7-11, subcostal n.

Question 18

Tendinous Intersections

Answer 18

The rectus abdominis muscle is broader and thinner above, narrow and thicker below. Its course is interrupted at 3 of 4 levels by superficial tendinous intersections (forms 6&8 packs). These intersections are fused to the anterior rectus sheath.

Question 19

Pyramidalis (O, I, A, N)

Answer 19

O: anterior surface of pubis ventral to the rectus abdominis

I: linea alba a short distance above its origin

A: tenses the linea alba

N: subcostal n.

Question 20

Rectus sheath: composition

Answer 20

composed of the combined aponeurosis of the external oblique, internal oblique, and transversus abdominis muscles

Question 21

Linea semilunaris

Answer 21

of rectus sheath: marks the transition of the muscular portions of the three anterolateral abdominal wall muscles to aponeurosis. The three layers are fused along this line and denote the beginning of the rectus sheath.

Question 22

Splitting of rectus sheath

Answer 22

Upper 3/4 of the sheath is divided into anterior and posterior laminae due to splitting of the internal oblique aponeurosis around the rectus abdominis muscle.

Question 23

Anterior rectus sheath

Answer 23

The anterior sheath is composed of the fused aponeuroses of the external and internal oblique muscles, while the posterior sheath is composed of the fused aponeuroses of the internal oblique and transversus abdominis muscles.

Question 24

linea alba

Answer 24

The fascias of the three anterolateral abdominal muscles, after enveloping the rectus abdominis, meet their counterparts from the opposite side at the midline thereby forming the linea alba.

Question 25

extent of the posterior rectus sheath

Answer 25

approximately midway between the umbilicus and the pubic symphysis the posterior sheath is lacking since all three aponeurotic layers now fuse and pass anterior to the rectus abdominis.

Question 26

Arcuate line

Answer 26

The point at which the posterior rectus sheath ends. It can be viewed either by looking at the abdominal wall from inside the abdominal cavity or by elevating the rectus abdominis anteriorly.

Question 27

Order of layers of the abdominal wall (superficial to deep) at approximate level of the umbilicus just off the midline

Answer 27

1. skin
2. superficial fascia (fatty layer, membranous layer)
3. anterior rectus sheath
4. rectus abdominis muscle
5. posterior rectus sheath
6. transversalis fascia
7. extraperitoneal connective tissue
8. peritoneum

Question 28

three connective tissue layers internal to the posterior rectus sheath, from superficial to deep

Answer 28

transversalis fascia, extra-peritoneal connective tissue (= subserous fascia), parietal peritoneum

Question 29

fold or ligament

Answer 29

when peritoneum overlays a structure embedded in the extraperitoneal connective tissue it is referred to as a fold or ligament. Depressions between these peritoneal folds are referred to as FOSSAE.

Question 30

Umbilical folds

Answer 30

median umbilical fold- formed by the median umbilical ligament, the remnant of the urachus (allantois)

medial umbilical folds- formed by the medial umbilical ligaments (obliterated umbilical arteries)

lateral umbilical folds- formed by the inferior epigastric vessels.

Question 31

Inguinal fossae

Answer 31

supravesical fossa- fossae above the bladder between the median and medial umbilical folds

medial inguinal fossa- fossa between the medial and lateral umbilical folds (site of direct inguinal HERNIAS)

Lateral inguinal fossa- fossa lateral to the lateral umbilical fold (site of INdirect inguinal HERNIAS)

Question 32

Vascular beds of anterior and lateral abdominal wall

Answer 32

The arterial suply to the anterior and lateral abdominal wall forms 2 separate vascular beds:

a- a superficial vascular bed coursing in the subcutaneous connective tissue layer originating above from PERFORATING branches of deeper vessels found within the muscular layer and below from branches of the FEMORAL artery

b- a deep vascular bed coursing within the muscular layer originating above from the SUBCLAVIAN artery, in mid-abdomen from the AORTA, and below from the EXTERNAL ILIAC ARTERY.

Question 33

Superficial (subcutaneous) circulation of superior abdomen (above the umbilicus)

Answer 33

accomplished by perforating branches of arteries located in the muscular layer:
1- superior epigastric aa
2- musculophrenic aa
3- intercostal aa
4- subcostal aa
5- lumbar aa

Question 34

Superficial (subcutaneous) circulation of inferior abdomen (below umbilicus)

Answer 34

accomplished by branches of the femoral artery. These branches, after traversing the saphenous opening of the groin, course within the membranous layer of the subcutaneous connective tissue to their respective destinations.
1- superficial epigastric a (umbilical region)
2- superficial circumflex iliac a. (iliac region
3- superficial external pudendal a. (suprapubic, pubic and genital regions)

Question 35

Deep (muscular) circulation is accomplished by which arteries?

Answer 35

Musculophrenic a.
Superior epigastric a.
Posterior intercostal arteries (10&11) and the subcostal a.
Lumbar aa.
Inferior epigastric a.
Deep circumflex iliac a.

Question 36

Musculophrenic artery

Answer 36

• one of the terminal branches of the internal thoracic a.
• courses deep to the costal cartilages of ribs 7-11
• provides anterior intercostal aa 7-11
• passes into the anterolateral abdominal wall between the internal oblique and transversus abdominis muscles
• anastomoses with 10th & 11th posterior intercostal & subcostal aa. and ascending branch of the deep circumflex iliac a. and lumbar aa.

Question 37

Superior epigastric a.

Answer 37

• one of the terminal branches of the internal thoracic a.
• pierces the posterior rectus sheath
• courses between the sheath and the rectus abdominis muscle
• ansastomoses with the inferior epigastric a. near the umbilicus

Question 38

Posterior intercostal aa (10 & 11) and the subcostal a.

Answer 38

• direct paired branches of the aorta above and below the diaphragm, respectively
• pass laterally and forward between the transversus abdominis and internal oblique muscles
• anastomose within the muscle layer with branches of the musculophrenic, superior epigastric, lumbar and deep circumflex iliac arteries

Question 39

lumbar arteries

Answer 39

• abdominal counterpart of thoracic intercostal arteries
• four paired branches arise from the abdominal aorta at the upper level of the first four lumbar vertebrae
• pass laterally for a short distance to provide branches mainly to the posterior and posterolateral abdominal wall musculature

Question 40

inferior epigastric a.

Answer 40

• arises from the external iliac a. prior to its passing beneath the inguinal ligament.
• passing medial to the deep inguinal ring, it angles toward the umbilicus within in the extraperitoneal connective tissue layer raising the lateral umbilical fold
• ascending the anterior abdominal wall internally, it enters the posterior rectus sheath where it will anastomose with the superior epigastric a. above the level of the umbilicus
• near its origin it provides branches to the spermatic cord, round ligament of the uterus, and dorsum of the pubis; along its course it anastomoses with branches of the lower six posterior intercostal aa. close to the lateral border of the posterior rectus sheath.

Question 41

deep circumflex iliac a.

Answer 41

• arises from the external iliac a. distal and lateral to the origin of the inferior epigastric a.
• courses lateralward toward the ASIS to perforate the transversus abdominis muscle to run between it and the internal oblique along the iliac crest
• provides an ascending branch which anastomoses with the last two posterior intercostal, subcostal, musculophrenic and lumbar aa.
• the direct continuation of the deep circumflex iliac a. anastomoses with the iliolumbar a.

Question 42

Venous drainage of abdomen– cutaneous and subcutaneous regions

Answer 42

accomplished by venae comitantes of the arteries which supply this region, such that tributaries drain:

• superiorly to the AXILLARY vein
• inferiorly to the GREATER SAPHENOUS vein

Question 43

venous drainage of musculature of the abdominal wall

Answer 43

also accomplished by venae comitantes of the arterial supply, such that tributaries drain:

• superiorly to the SUBCLAVIAN vein
• laterally and posteriorly to the SVC and IVC
• inferiorly to the EXTERNAL ILIAC vein

Question 44

Tributaries to the axillary vein (superficial drainage)

Answer 44

thoracoacromial v, lateral thoracic v.

Question 45

Tributaries to the greater saphenous vein (superficial drainage)

Answer 45

superficial epigastric v., superficial circumflex iliac v., superficial external pudendal v.

Question 46

Important example of anastomotic channels above and below the umbilicus

Answer 46

Although the venous drainage of the superficial abdominal wall is accomplished by venae comitantes of the arterial supply, the drainage pattern consists of highly anastomotic channels above and below the umbilicus. An important example of this anastomosis occurs between superficial veins of the thorax and abdomen in the form of thoraco-epigastric veins, veins which connect lateral thoracic veins above with superficial epigastric veins below.

Question 47

Tributaries to the subclavian vein (muscular wall drainage)

Answer 47

superior epigastric v.

musculophrenic v.

Question 48

Tributaries to the external iliac vein (muscular wall drainage)

Answer 48

inferior epigastric v.

deep circumflex iliac v.

Question 49

Tributaries to the IVC (muscular wall drainage)

Answer 49

lumbar vv.

Question 50

tributaries to the SVC via the azygous system (muscular wall drainage)

Answer 50

Posterior intercostal vv. 10 & 11

subcostal v.

Question 51

Cutaneous lymphatics

Answer 51

an anastamosing plexus of lymphatics exits in the subcutaneous connective tissue of the thorax, abdomen, perineum and genitalia, and drains by the following scheme:

• above the transumbilical plane, lymph drains toward the thorax (parasternal nodes) and axilla (lateral pectoral nodes)
• below the transumbilical plane, lymphatic channels following subcutaneous blood vessels drain to superficial inguinal lymph nodes

Question 52

Superficial inguinal lymph nodes

Answer 52

represented by as many as 20 lymph nodes arranged in a “T” shaped mass located just inferior to the inguinal ligament. Generally, they receive drainage from the lower abdomen, perineum and genitalia, and lower limb.

Question 53

Lymphatics of the muscular wall

Answer 53

Lymphatic drainage of the muscular abdominal wall parallels its major vascular supply and therefore follows this scheme:

• along the path of the inferior epigastric vessels to EXTERNAL ILIAC NODES
• along the path of the deep circumflex iliac vessels to EXTERNAL ILIAC NODES
• along the path of lumbar vessels to LUMBAR NODES (nodes along the lumbar portion of the aorta and IVC)
• along the path of the superior epigastric vessels to PARASTERNAL NODES (nodes along the path of internal thoracic vessels on the internal surface of the sternum.

Question 54

Comparing subcutaneous lymphatic drainage of the abdominal wall with the lymphatic drainage of the muscular abdominal wall

Answer 54

Subcutaneous lymphatics generally drain to lymph nodes located SUPERFICIALLY in the subcutaneous tissue of the thigh and thorax (axilla) while the lymphatics of the muscular abdominal wall and testes drain to nodes located INTERNALLY in the abdominopelvic cavity and thorax.

Question 55

Dermatomes of the abdomen

Answer 55

represented by cutaneous branches of ventral rami of spinal nerves T7-T11 (referred to as thoracoabdominal intercostal nn.)

Question 56

Innervation to the muscles of the abdominal wall is accomplished by…

Answer 56

ventral rami of spinal nerves T7-L4. Branches of ventral rami T7-T11 and T12 originate as intercostal and subcostal nerves, respectively. Branches of ventral rami L1-L4 originate within the LUMBAR PLEXUS.

Question 57

Thoracoabdominal intercostal nn. (T7-T11)

Answer 57

Pass from intercostal spaces to course between the transversus abdominis and the internal oblique muscles.

As they pass medially they are directed inferiorward such that:

1. the 7th thoracoabdominal intercostal nn. terminate in the region just inferior to the xiphoid process
2. the 10th thoracoabdominal intercostal nn. terminate in the region of the umbilicus
3. they provide lateral cutaneous branches, muscular branches to ALL anterolateral and anterior abdominal muscles (except pyramidalis) and terminate as anterior cutaneous nerves.

Question 58

What nerves pierce the transversus abdominis muscle at its posteromedial most extent and run forward between this muscle and the internal oblique for varying distances?

Answer 58

Subcostal n. (T12)
Iliohypogastric n.
Ilioinguinal n.

Question 59

Subcostal n. (T12)

Answer 59

has a course and distribution similar to the thoracoabdominal intercostal nn., however, its lateral cutaneous branch distributes to the upper gluteal area. Muscularly, it provides innervation to the EAO, IAO, TA and the SOLE innervation to the pyramidalis muscle.

Question 60

Iliohypogastric n.

Answer 60

(L1; 50% T12-L1)

1. Pierces the internal oblique muscle medial and superior to the ASIS and runs inferiorly and medially between the internal and external oblique muscles.
2. Provides a lateral branch to the gluteal area, innervates the EAO, IAO, TA and communicates with the ilioinguinal nerve and terminates as anterior cutaneous branches to the SUPRAPUBIC REGION.

Question 61

Ilioinguinal n.

Answer 61

(L1)

1. Pierces the internal oblique near the deep inguinal ring
2. Parallels the course of the iliohypogastric n. on a slightly inferior plane
3. Courses through the inguinal canal where it runs on the surface of the spermatic cord and follows it through the superficial inguinal ring.
4. Provides muscular branches to the IAO and TA
5. Provides cutaneous branches to the upper medial thigh and terminates as the ANTERIOR SCROTAL/ LABIAL BRANCH supplying cutaneous innervation to the root of the penis and scrotum in the male and to the mons pubis and labia majora in the female.

Question 62

Inguinal ligament

Answer 62

inferior rolled-under border of the external abdominal oblique aponeurosis extending from the ASIS to the pubic tubercle. It forms a “shelving border” which attaches to the fascia lata of the thigh and, with the iliopubic tract of transversalis fascia, participates in forming the floor of the inguinal canal. Together the inguinal ligament and iliopubic tract form a “flexor retinaculum” which spans the subinguinal space containing the iliopsoas, pectineus, and the femoral sheath and its contents.

Question 63

parts of the inguinal ligament

Answer 63

superficial inguinal ring
lateral (inferior) crus
medial (superior) crus
intercrural fibers

Question 64

superficial inguinal ring

Answer 64

medial opening of the inguinal canal through the inguinal ligament. It passes the spermatic cord of the male, the round ligament of the uterus of the female. Triangular in shape, its apex is directed laterally toward the ASIS, while its base is located at the pubic crest. Superior and inferior margins are referred to as crura.

Question 65

Lateral (inferior) crus of the inguinal ligament

Answer 65

formed by the thick portion of the inguinal ligament which attaches to the pubic tubercle

Question 66

Medial (superior) crus of the inguinal ligament

Answer 66

formed by the portion of the inguinal ligament which attaches to the pubic symphysis. It is thinner than its lateral counterpart.

Question 67

Intercrural fibers

Answer 67

reinforcing fibers located perpendicular to the crura lateral to the superficial inguinal ring.

Question 68

Lacunar ligament

Answer 68

medial rolled-under portion of the inguinal ligament which, after being crossed by the spermatic cord, attaches to the pectineal line lateral to the pubic tubercle. When viewed laterally it presents a crescentic free border, hence the name “lacunar” ligament.

Question 69

pectineal ligament

Answer 69

the continuation of the lacunar ligament laterally along the pectineal line of the superior ramus of the pubic bone. Important as an anchoring point for sutures during inguinal hernia repair.

Question 70

Reflected inguinal ligament

Answer 70

fibers continued from the pubic tubercle medially and superiorly toward the linea alba which intersect with the contralateral external oblique aponeurosis.

Question 71

external spermatic fascia

Answer 71

outermost fascial layer of the spermatic cord derived from the external abdominal oblique aponeurotic layer.

Question 72

conjoined tendon

Answer 72

the most medial and inferior common fused aponeuroses of the internal abdominal oblique and transversus abdominis muscles. The fibers of these two muscles arch from the inguinal lligament where they originate to the pubis where they terminate immediately deep to the superficial inguinal ring. The fusion of these two layers helps strengthen a potentially weak area of the anterior abdominal wall.

Question 73

Inguinal Canal Boundaries

Answer 73

floor: inguinal ligament and iliopubic tract of transversalis fascia
Anterior wall: external oblique aponeurosis with lowest fibers of internal oblique
Roof: arching fibers of the internal oblique and transversus abdominis which originate from the inguinal ligament and attach medially to the superior pubic ramus
Posterior wall: transversalis fascia laterally; conjoined tendon medially

Question 74

The internal oblique’s special relationship to the inguinal canal

Answer 74

The lowest fibers of the internal oblique muscle arise from the inguinal ligament lateral and anterior of the deep inguinal ring. They arch over the canal and insert with the fibers of the transversus abdominis as the conjoined tendon posterior to the superficial ring. The internal oblique therefore participates in forming a portion of the anterior wall, roof, and a portion of the posterior wall of the inguinal canal.

Question 75

Entrance to the inguinal canal

Answer 75

via the superficial inguinal ring

Question 76

Contents of the inguinal canal

Answer 76

Male: spermatic cord, ilioinguinal n., genital branch of the genitofemoral n.

Female: round ligament of the uterus, artery and vein of the round ligament, ilioinguinal n.

Question 77

Testes embryonic development

Answer 77

testes develop from coelomic epithelial cells which develop in the extraperitoneal connective tissue layer of the posterior abdominal wall at the upper lumbar level in an area known as the urogenital ridge.

Question 78

Descent of the testes

Answer 78

As a testis is formed it bulges into the future abdominal cavity raising the peritoneum as it grows.

At its superior and inferior poles, the testis has attached to it peritoneal folds. The superior fold contains the future testicular vessels, nerves and lymphatics. The inferior fold will eventually form the gubernaculum testis.

At the distal site of attachment of the gubernaculum testis, the anterior abdominal wall will evaginate (pouch outward). The peritoneal contribution (innermost layer) of this evagination is called the processus vaginalis. As the processus vaginalis pushes into the scrotal swelling (future scrotum) it carries with it contributions of the muscular and fascial abdominal layers it traverses.

Due to differential growth rates of the embryo, the testis is drawn by its scrotal attachment, the gubernaculum, into the scrotum. As the testis traverses the inguinal canal following the path of the processus vaginalis, the layers of the abominal wall are also applied to it as well as to its trailing future spermatic cord.

After the testis has fully descended, the processus vaginalis is applied to the testis forming an incomplete serous sac, the tunica vaginalis testis.

More proximally, the processus vaginalis atrophies and becomes a fibrous cord thereby closing the deep inguinal ring leaving only a dimple marking its former existence in the anterior abdominal wall.

Question 79

gubernaculum testis

Answer 79

a fibrous connective tissue cord which attaches the inferior pole of the testis to the site of the future deep inguinal ring on the anterior inferior abdominal wall.

Question 80

Clinical note: processus vaginalis relationship to indirect inguinal hernia

Answer 80

it is thought that the processus vaginalis is open in 50% of infants until one month after birth; this may lead to weakness of the anterior abdominal wall in the inguinal region contributing to indirect inguinal hernia.

Question 81

Cryptorchidism

Answer 81

undescended or incompletely descended testes.

Question 82

Spermatic cord coverings

Answer 82

1. External spermatic fascia - from external abdominal oblique; applied as cord penetrates the superficial inguinal ring
2. Cremaster muscle and associated fascia- from internal abdominal oblique; applied midway through the inguinal canal
3. Internal spermatic fascia- from transversalis fascia, covers entire extent of cord
   Tunica vaginalis testis- peritoneum via processus vaginalis testis
   Tunica albuginea- outermost connective tissue capsule of testis

Question 83

Contents of the spermatic cord

Answer 83

1-5 embedded in extraperitoneal connective tissue and surrounded by internal spermatic fascia. 6 courses between the cremaster and the internal spermatic fascia.

1- ductus deferens- efferent duct from epididymis
2- testicular artery- branches directly from the abdominal aorta (TV2)
3- deferential artery and vein- branch of the umbilical a. from internal iliac a.
4.- pampiniform plexus of veins - will form testicular vein; on the right will drain to the IVC, on the left will drain to the left renal vein
5- lymphatics draining testis- drain to lumbar nodes
6- genitofemoral nerve (genital branch L1-L2)- innervation of cremaster muscle

Question 84

Autonomic nerve fibers to the testes course…

Answer 84

on the surface of the testicular artery and ductus deferens

Question 85

Abdominal wall hernias (general concept)

Answer 85

are protrusions of ANY portion of the abdominal contents beyond the confines of the abdominal cavity.

Question 86

Types of adominal wall hernias

Answer 86

epigastric, umbilical, spigelian, incisional, inguinal

Question 87

Epigastric hernias

Answer 87

a- occur along the linea alba between the xiphoid process and umbilicus
b- can be due to gaps of CT fibers between the linea alba and rectus sheath, stresses of obesity and aging, consequence of surgical intervention

Question 88

Umbilical hernias

Answer 88

occur through umbilical ring
most common in neonates
due to weakness at site from incomplete closure of umbilical cord ligation and increased intra-abdominal pressure
associated with low birth weight

Question 89

Spigelian hernias

Answer 89

occur along the semilunar lines

associated with obesity and in ages over 40 years

Question 90

Incisional hernias

Answer 90

occur at site of previously healed surgical scar

Question 91

Direct inguinal hernia: definition

Answer 91

protrusion of abdominal contents through the posterior wall of the inguinal canal MEDIAL to the inferior epigastric vessels

Question 92

Direct inguinal hernia: rationale

Answer 92

transversalis fascia located between the inferior epigastric vessels and the conjoined tendon is termed “weak” fascia due to the occurrence of hernias in this area.

Question 93

Inguinal triangle

Answer 93

= Hesselbach's triangle
boundaries:
lateral and superior: inferior epigastric vessels
medial: lateral border rectus abdominis
base: inguinal ligament

Question 94

Direct inguinal hernia: course

Answer 94

herniated material first passes through the weak fascia of the posterior wall of the inguinal canal (located directly behind the superficial inguinal ring, lateral to the conjoined tendon, and medial to the inferior epigastric vessels), crosses the canal but does not traverse its lenth, and passes out through the superficial inguinal ring. Direct inguinal hernias very seldom extend into the scrotum.

Question 95

Direct inguinal hernia: occurrence

Answer 95

15-25% of inguinal hernias
majority occur bilaterally; rare in women
medial to inferior epigastric vessels
through “weak fascia’ of Hesselbach’s triangle
bulge in anterior wall does NOT extend into scrotum or labium

Question 96

Indirect inguinal hernia: definition

Answer 96

Protrusion of abdominal contents through the deep inguinal ring LATERAL to the inferior epigastric vessels.

Question 97

Indirect inguinal hernia: rationale

Answer 97

weakness at the deep inguinal ring is due to:

• passage of the spermatic cord/ round ligament of uterus
• failure of the processus vaginalis to completely close

Question 98

indirect inguinal hernia: course

Answer 98

herniated material passes through the deep inguinal ring, traverses the entire length of the inguinal canal, protrudes through the superficial inguinal ring and extends into the scrotum or labia majora.

Question 99

Indirect inguinal hernia: occurrence

Answer 99

75-85% of inguinal hernias
usually occur on the right; 20x greater in males
lateral to inferior epigastric vessels
follow path of inguinal canal
extends into scrotum or labium

Question 100

Determining the origin (direct or indirect) of herniated material which has protruded through the superficial inguinal ring…

Answer 100

by the covering of the hernia sac. Both direct and indirect hernias can possess a hernia sac which is covered by the fascial layers which cover the spermatic cord. However, the hernia sac of a direct inguinal hernia should have only a covering of peritoneum and transversalis fascia, while an INDIRECT hernia can be covered first with the constituents of the spermatic cord, i.e. ductus deferens, testicular a., pampiniform plexus, etc., then all of the fascial coverings located in the cord.

Question 101

Natural protection against inguinal hernias is afforded by the…

Answer 101

internal abdominal oblique and transversus abdominis muscles as they form MUSCULO-APONEUROTIC ARCADES which clamp down or otherwise cause the area of the posterior wall of the inguinal canal to become narrower during standing, straining or coughing. Therefore, surgeons performing appendectomies are careful to NOT cut the iliohypogastric nerve which provides innervation to these muscles in the inguinal region.