5. Abdominal Wall + Inguinal Region

Two main issues for development of the abdominal wall

1. Early in development the right + left sides of the flat multilayered embryonic disc fold ventrally and fuse - essential step for forming embryo 2. Migration of the testis from location near kidney to the scrotum (one of last major changes in embryology - after all major organs have formed and in locations)

List + Describe Functions of Abdominal Wall

1. Form a physical barrier that protects abdominal viscera (and when appropriate, a fetus or two or more) 2. Produce movements of the trunk + provide stability 3. Generate heat by muscle contraction and retain heat with insulating layers of muscle + adipose tissue 4. Store energy in the form of lipids

Two Kinds of Inguinal Hernias

1. Indirect Inguinal Hernia (L): through deep inguinal ring, inguinal canal + superifical inguinal ring - typically congenital (male child) - Lateral to inferior epigastric a., along the path of testis descent 2. Direct Inguinal Hernia (R): through or around weakened conjoint tendon then through superficial inguinal ring (no deep inguinal ring) - Typically older adult (years of accumulated microtrauma from elevated intra-abdominal pressure) - More common in males - Medial to inferior epigastric a. Often a part of intestine

List all of the tissue layers from skin to the abdominopelvic cavity, inferior to the arcuate line.

1. Skin, Camper's fatty layer of superficial fascia, Scarpa's membranous layer of superficial fascia, 2. deep fascia of external oblique aponeurosis, external oblique aponeurosis, all of internal oblique aponeurosis, transversus abdominis aponeurosis 3. rectus abdominis, transversalis fascia, peritoneum

List all of the tissue layers from skin to the abdominopelvic cavity, superior to the arcuate line.

1. Skin, Camper's fatty layer of superficial fascia, Scarpa's membranous layer of superficial fascia. 2. Deep fascia of external oblique aponeurosis, external oblique aponeurosis, half of internal oblique aponeurosis 3. rectus abdominis, half of internal oblique aponeurosis, transversus abdominis aponeurosis, transversalis fascia, peritoneum.

Preperitoneal vs. retroperitoneal

140-141

Creamsteric reflex, Masses, Inguinal hernias, Indirect inguinal hernias, direct inguinal hernias, femoral hernias, potential problems

147 - 150

9 Regions of Anterolateral abdominal Wall

9 Regions of Anterolateral abdominal Wall - centered around umbilical - More specific but harder to map L. Hypochondriac describes spleen location very well

Public Symphysis

A hard, bony, and cartilaginous prominence found at the midline in the lowermost portion of the abdomen where the two halves of the pelvic ring are joined by cartilage at a joint with minimal motion. allows some movement to facilitate childbirth

Epididymis

A long, coiled duct on the outside of the testis in which sperm mature.

Pubic Tubercle

An attachment point for the inguinal ligament.

What is the superolateral attachment point of the inguinal ligament? What is the inferomedial attachment point of the inguinal ligament?

Anterior Superior Iliac Spine Pubic Tubercle

Layers + contents of spermatic cord

As testis goes through abdominal wall it gathers layers that follow behind it to form spermatic cord Superficial fascia >> tunica dartos (wall of scrotum fascia w/ smooth muscle) >> External oblique fascia >> external spermatic fascia (outer most layer of spermatic cord) Internal oblique fascia >> cremasteric fascia (internal oblique m. goes along - cremaster muscle (striated)) Transversalis fascia >>internal spermatic fascia Processus vaginalis >>tunica vaginalis Tunica Vaginalis = favorite for exams!

Fatty layer of superficial Fascia

Camper's Fascia Superficial to membranous layer - very thick in some people

Inguinal Ligament + external oblique m.

Connects: Anterior Superior Iliac Spine to Pubic Tubercle Inguinal ligament is not distinct from the external oblique aponeurosis, but it is called a ligament because it goes from bone to bone with little or no muscle. The superifical inguinal ring is a triangular hole in the inguinal ligament

The anatomical actions of external oblique muscle and internal oblique muscle cannot be the same. The angles of their fiber angles and attachments give them different actions. Which one of them flexes the trunk and rotates it contralaterally? Ipsilaterally?

Contralateral - External oblique m. Ipsilateral - Internal oblique m.

Cremaster Muscle

Cremaster M. Innervation: genital branch of genitofemoral nerve Pulls the scrotum closer to the body in cold temperatures and relaxes to let the testicles be farther away from the body in warmer weather term-70 Deep to Cremasteric Fascia Superficial to Internal Spermatic Fascia Made from internal oblique muscle - Fascia from internal oblique fascia

What pair of components do the internal oblique muscle and its fascia contribute to the spermatic cord?

Cremasteric muscle + cremasteric fascia.

Coming from inside the pelvic cavity, what opening or space do the ductus deferens, testicular artery and pampiniform plexus of testicular veins pass through to enter the inguinal canal?

Deep Inguinal Ring

Coming from inside the pelvic cavity, what opening or space does the round ligament pass through to enter the inguinal canal?

Deep Inguinal Ring

In terms of surface anatomy, where is the deep inguinal ring located? In terms of surface anatomy, where is the superficial inguinal ring located? How deep is the superficial inguinal ring? (Name the muscle layer.)

Deep Iring: Halfway bw the ASIS + pubic tubercle Superficial Iring: Immediately lateral to pubic tubercle - at the depth of the inguinal ligament or external oblique muscle

Deep Inguinal Ring

Defect in inferior oblique muscle Located 1cm above lingual ligament (halfway between anterior superior iliac spine + pubic tuberacle) Ductus Deferens + testicular a. pass through Internal Seprmatic Fascia begins here Entrance of Inguinal canal

Internal Spermatic Fascia

Derived from transversalis fascia Deep to Cremaster m., cremasteric fascia, External spermatic fascia

In what type of groin area hernia do the herniated contents pass through the deeper layers of the abdominal wall by opening a space medial to the deep inguinal ring? In the type of hernia described above, what is the relationship of the hernia sac to the inferior epigastric artery?

Direct inguinal hernia. Medial to the artery. Happens to Adults

External Oblique m.

External Oblique M. Innervation: Anterior Rami Flexes, laterally flexes and rotates trunk contralaterally Origin: Ribs Insertion: Illiac Spine

What muscle layer has the inguinal ligament as its inferior edge? In addition to that, the next muscle deeper has part of its origin from the lateral part of the inguinal ligament. Name that muscle.

External Oblique Muscle Internal Oblique Muscle

From what artery does the inferior epigastric artery branch? In relation to the rectus sheath and rectus abdominis muscle, where is the distal (superior) part of the inferior epigastric artery located?

External iliac artery. In the sheath, posterior to the rectus abdominus muscle. Anterior to transverse abdominis

What aponeurotic layers form the rectus sheath?

External oblique aponeurosis Internal oblique aponeurosis Transversus abdominis aponeurosis. Aponeurosis: strong sheet of tissue that acts as a tendon to attach muscles to bone

What layer does the external oblique aponeurosis (or its fascia) contribute to the spermatic cord?

External spermatic fascia

What are the three fascial layers and the muscular layer of the spermatic cord?

External spermatic fascia cremasteric fascia and cremaster muscle internal spermatic fascia.

Inguinal Ligament

Floor of the Inguinal Canal - ligament extending from pubic bone to anterior superior iliac spine, forming lower border of abdomen

Conjoint Tendon

Fusion of the aponeurosis of the transverse abdominis and internal abdominal oblique - Attach to pubic Bone Direct Inguinal Hernia: through or around weakened conjoint tendon through superficial inguinal ring

Contrasting Indirect + Direct Inguinal Hernias

Indirect Hernia: in processus vaginalis - Through deep inguinal ring - Lateral to inferior epigastric a. Direct Hernia: ignores fetal migration pathway - Medial to inferior epigastric *Both approach or go through Superficial Inguinal Ring

In what type of groin area hernia do the herniated contents pass through the deep inguinal ring? what is the relationship of the hernia sac to the inferior epigastric artery? Is this type of hernia commonly a pediatric condition or a condition with causes that arise in adult life?

Indirect inguinal hernia. Lateral to the inferior epigastric artery Pediatric Condition

Inferior Epigastric Artery

Inferior Epigastric Artery (Right + Left) Branches from: External Iliac artery distal end Supplies: abdominal wall and external genitalia Ascends posteriorly to transverse abdominis until it passes through the arcuate line then ascends anteriorly to transverse abdominis m. and inferiorly to rectus abdominus until it reaches arcuate line

What feature of the internal surface of the abdominal wall is found medial to the deep inguinal ring?

Inferior epigastric artery

Inguinal Regions of Abdomen

Inferior to Iliac Tuberacles Lateral to clavicular lines Right Inguinal Region: the appendix, cecum, and the right iliac fossa Left Inguinal Region: part of the descending colon, the sigmoid colon, and the left illiac fossa

Hypogastric Region of Abdomen

Inferior to Iliac Tuberacles Medial to clavicular lines Contains: bladder, part of the sigmoid colon, the anus, and many organs of the reproductive system, such as the uterus and ovaries in females and the prostate in males.

Lumbar Regions of Abdomen

Inferior to Subcostal Line Superior to Iliac Tuberacles Lateral to clavicular lines Right Lumbar Region: The right lumbar region consists of the gallbladder, the left kidney, part of the liver, and the ascending colon. Left Lumbar Region: consists of the descending colon, the left kidney, and part of the spleen.

Umbilical region of Abdomen

Inferior to Subcostal Line Superior to Iliac Tuberacles Medial to clavicular lines Contains: small intestine, transverse colon of large intestine

The fascicles of the external oblique muscle have approximately the same direction across the entire muscle. Where on the surface of the anterolateral abdominal wall are the fascicles of the other two muscle layers approximately parallel to the fascicles of the external oblique muscle?

Inferior to the anterior superior iliac spine, all three muscles run more or less from superior and lateral to inferior and medial. (V)

Purpose of Inguinal Canal?

Inguinal Canal Closes like a valve to prevent hernia - offset of two holes (deep + superficial inguinal rings) Deep inguinal ring: midway b/w anterior superior illiac spine + pubic tubercle Offset b/w the deep + superficial inguinal rings is functionally similar to the anatomy of the foramen ovale of the fetal heart

Inguinal Ligament Incision - Female

Inguinal Ligament (anterior wall) reveals inguinal canal - Internal oblique muscle and conjoint tendon as posterior wall as canal This shows the superficial inguinal ring cut open - Round ligament as lump of adipose tissue running through Canal is not a tube it is more a gap between muscle layers

Internal Oblique m.

Internal Oblique M. Innervation: Anterior rami of T7-T12 Flexes, laterally flexes and rotates trunk ipsilaterally Origin: Iliac Crest Insertion: Ribs

Which two of the three muscles of the anterolateral abdominal wall have tendons that fuse to form the conjoint tendon?

Internal oblique muscle + transversus abdominis muscle.

What "layer" does the transversalis fascia of the abdominal wall (fascia on the deep side of the transversus abdominis muscle) contribute to the spermatic cord?

Internal spermatic fascia

From what artery does the superior epigastric artery branch? (Actually, it continues in a straight line.) In relation to the rectus sheath and rectus abdominis muscle, at what depth is the superior epigastric artery located?

Internal thoracic artery. In the sheath, posterior to the rectus abdominus muscle.

Anterior Superior Iliac Spine

Lateral end attachment of inguinal ligament Subcutaneous and can be palpated

Lower part of Rectus Sheath

Lower part of Rectus Sheath is thin posteriorly - Anterior shift of the transversus abdominins aponeurosis From sternum to pubic bone: External oblique aponeurosis is anterior to the rectus abdominus m. Superior to arcuate line: Internal oblique aponeurosis divides contributing to anterior + posterior layer of rectus sheath - Posterior covers posterior of rectus abdominis (above arcuate line) - Anterior is everything else on top Inferior to arcuate line: all of internal oblique + transversus abdominus aponeurosis pass anterior to rectus abdominus m.

Name the three regions that are medial to the two midclavicular lines. Name the three regions that are lateral to the two midclavicular lines.

Medial: Epigastric region, umbilical region, hypogastric region Lateral: Right or left hypochondriac region, right or left lumbar region, right or left inguinal region

In normal male development, does the testis migrate into the scrotum in embryonic life, early fetal life, mid-to-late fetal life or post-natally?

Mid-to-late fetal life.

Migration of Testis + Kidney

Migration: Kidney Up, Testis Down! In embryo gonads begin development in location that becomes posterior abdominal wall - development of testis or ovary as organ is completed anatomically there Gubernaculum: Pulls testis towards deep inguinal ring, then into inguinal canal - Females round ligament is homologous to the male's gubernaculum (because in canal) Fetal ovary also descends just not out through the abdominal wall

How to distinguish types of inguinal hernias

Only reliable way to distinguish the two types of inguinal hernias is the relationship to epigastric a. - Surgeon will not know what type of hernia a pt has until surgery is performed Must exit the superficial inguinal ring Indirect: Lateral Direct: Medial

Pubic Crest

Origin: Rectus abdominus

Pampiniform venous plexus

Pampiniform Venous Plexus Drains: Testes + epididymis (and proximal end of ductus deferens) network of veins that surround testicular arteries to absorb heat cools arterial blood to keep the testes below core temperature Follows same path as testicular a. + ductus deferen distal to the deep inguinal ring

What tissue layer of the adult abdominal wall shares a developmental source with the epithelial lining of the tunica vaginalis of the testis?

Peritoneum.

Round Ligament of Uterus

Prevents posterior Movement by pulling from the front of the uterus. Goes from the fundus of the uterus through the INGUINAL CANAL and attaches to the labia majora

Quadrant System of Dividing Abdominal Wall

RU, LU, RL, LL Quadrants - based on umbilicus

Rectus Abdominis m.

Rectus Abdominis m.: runs vertically from costal cartilages + sternum to the pubic bone Innervation: Anterior rami of T6-T12 Produces: Flexion of trunk Stretched by: Extension of trunk Origin: pubic crest Insertion: xiphoid process + costal cartilages

Rectus Sheath

Rectus Sheath: fibrous covering that the aponeuroses of the three lateral muscles form around the rectus abdominus m. - aponeuroses: Fibrous or membranous sheet connecting a muscle and the part it moves that cross over or under rectus abdominus muscle - Rectus abdominus is encased posteriorly + anteriorly Arcuate Line of Posterior Rectus Sheath: transition between thick + thin tissue - line is inferior to the umbilicus on the deep side of the abdominal wall

What muscle is encased in the rectus sheath?

Rectus abdominis.

Round Ligament of Uterus emerges from...

Round Ligament of Uterus emerges from Superficial Inguinal Ring "ligamentum teres uteri" Connects Uterus to Subcutaneous Tissue: round ligament passes through the deep inguinal ring, into the inguinal canal, and then out through the superficial inguinal ring Most of ligaments length is inside of the pelvis

Membranous Layer of Superficial Fascia

Scarpa's Fascia Deeper membranous layer - lies below the superficial fatty layer (campers fascia) and anterior to abdominal muscles The deeper membranous layer of superficial fascia can be very obvious or rather subtle. Sometimes the surgeon finds that it is thick and sturdy enough to hold a suture. - The membranous layer of superficial fascia might be hard to distinguish from the deep fascia layer that is more closely adherent to the muscles and the connective tissues of the wall.

Superior Epigastric artery

Superior Epigastric Artery (Right + Left) Branches: continuation of the internal thoracic artery (R + L) - Branches at the Costal Margin Supplies: diaphragm + anterior abdominal wall Descends anteriorly to transverse abdominis m. and inferiorly to rectus abdominus

Hypochondriac Region of Abdomen

Superior to Subcostal Line Lateral to Midclavicular Lines Right hypochondriac region contains the right portion of the liver, the gallbladder, the right kidney, and parts of the small intestine Left hypochondriac region contains part of the spleen, the left kidney, part of the stomach, the pancreas, and parts of the colon

Epigastric Region of Abdomen

Superior to Subcostal Line Medial to Midclavicular Lines - It is located between the costal margins and the subcostal plane. Contains esophagus, stomach, liver, spleen

Testicular Artery

Testicular Artery Branches from: branch of the abdominal aorta Supplies: blood supply to testes Passes through deep + superficial inguinal rings Deep to cremaster m.

Be sure to inform yourself of the nature and appearance of the vessels inside the spermatic cord: the testicular artery, pampiniform venous plexus and ductus deferens. Of those three structures, which two look similar to each other?

Testicular artery and ductus deferens.

The inguinal canal closes like a valve to prevent hernia

The inguinal canal closes like a valve to prevent hernia Superior View Deep inguinal ring: hole in transversalis fascia (deep to transversus m.) - Lateral to inferior epigastic a. Blue: External oblique layer (inguinal lig) Green: Transversalis fascia deep to transversus abdominis m. Red dot: inferior epigastic a

Parietal Peritoneum

The outer layer of the peritoneum that lines the interior of the abdominal wall Layers: Skin Subcutaneous tissues (further divided into the more superficial Camper's fascia and the deeper Scarpa's fascia) External oblique muscle Internal oblique muscle Transversus abdominis muscle Transversalis fascia Parietal peritoneum

The posterior layer of the rectus sheath is ___ above the arcuate line and ___ below the line.

The posterior layer of the rectus sheath is thick above the arcuate line and thin below the line. Below Arcuate Line (Posterior): rectus sheath is made only of transversalis fascia located between rectus abdominis muscle and peritoneum Internal oblique aponeurosis is split around the rectus muscle above the line. Below the line all of the internal oblique aponeurosis and the transversus aponeurosis are anterior to the rectus muscle.

What is the linea alba of the anterior abdominal wall?

Thick line of dense connective tissue making the full thickness of the anterior abdominal wall between the right and left rectus sheathes.

Tendinous Intersections

Three transverse bands of collagen fibers that divide the rectus abdominis into segments - sheath and the rectus abdominis muscle are connected to each other Those lines are present even in people with thin, weak rectus muscles, but they are obvious only on people who have some bulk in the muscle and relatively little superficial adipose.

Transverse Abdominus m.

Transverse Abdominus m. Innervation: Anterior Rami of T7-T12 Compresses and provides structural support to adjacent abdominal muscles -No flexion or trunk rotation action Origin: Costal cartialges of 7-12 Insertion: Linea alba, pubic crest - Wraps all the way around almost to end of illiac crest

External Oblique Internal Oblique Transversus Abdominis

Transversus Abdominis: Deepest - Transverse in orientation almost Internal Oblique: fanning fibers - Perpendicular to external oblique. - Ascends as it wraps around body wall - inferior to illiac spine internal oblique fans downwards (w/ fasicles there nearly parrelle to external oblique m.) External Oblique: forms inguinal ligament - Fascicles are parallel to external intercostal m. - wraps around body toward midline - Most Inferior part: Anterior superior illiac spine to pubic tuberacle (2 points on one bone) **All 3 muscles run parallel in inguinal area Direction of fasciles: Ext obique: greasy hands in front pockets Int Oblique: wiping hands on scrubs Transversus Abdominus: satisfied with clean hands

Between what layers is the transversalis fascia of the abdominal wall located?

Transversus abdominis and parietal peritoneum. Skin Subcutaneous tissues (further divided into the more superficial Camper's fascia and the deeper Scarpa's fascia) External oblique muscle Internal oblique muscle Transversus abdominis muscle Transversalis fascia Parietal peritoneum

What muscle is deep to the internal oblique muscle, and what is its fiber direction?

Transversus abdominis muscle. Most of its fascicles are transversely oriented, although the more inferior fibers are angled from superior and lateral to inferior and medial. (V) - Inferiorly the same as external oblique

Tunica Dartos

Tunica Dartos - made from superficial fascia - has some muscle to pull scrotum in to keep warm in cold Fascia - the structure that separates the scrotum into two separate compartments internally

Iliac Crest

Upper margin of iliac bones Origin: Internal Oblique m.

Iliac Tubercle

Used to separate lumbar from inguinal The anterior portion of outer lip - landmark

Inguinal Canal

a short canal passing through the abdominal wall in the region of the groin in males Superificial Inguinal Ring (entrance) + Deep inguinal ring (exit) of canal

Ductus Deferens

carries sperm from epididymis to urethra

Subcostal line

connects the inferior borders of the lowest costal cartilages

Spermatic Cord

contains vas deferens, pampiniform plexus, and external cremaster muscle nerves

External Spermatic Fascia

derived from external oblique aponeurosis - surrounds tests + spermatic cord Superficial to cremasteric fascia + cremaster muscle

What is the direction of the fascicles of most of the internal oblique muscle? (We refer here to the more superior part of the muscle.)

from inferior and lateral to superior and medial. Like an n from the midline - same as internal intercostal m.

What is the direction of the fascicles of the external abdominal oblique muscle on the anterior abdominal wall?

from superior and lateral to inferior and medial. Looks like a V into the center - same as external intercostal muscles

Midclavicular Line

imaginary vertical line bisecting the middle of the clavicle in each hemithorax

Tunica Vaginalis of Testis

is the serous membrane that surrounds the front and sides of the testicle. Parietal layer: far more extensive than the visceral, extending upward for some distance in front and on the medial side of the cord, and reaching below the testis. Visceral layer: covers the greater part of the testis and epididymis, connecting the latter to the testis by means of a distinct fold. made from peritoneum

Costal Margin

lower border of rib margin formed by the medial edges of the 8th, 9th, and 10th ribs

xiphoid process

lower, narrow portion of the sternum

Testis

male reproductive organ that produces sperm and hormones Includes Tunica Vaginalis + distal sperm cord Deep to internal spermatic fascia, cremaster m., cremasteric fascia + external spermatic fascia

Linea Alba

midline tendinous seam joining the abdominal muscles Formed where anterior + posterior layers of rectus sheath blend with each other and with fibers of contralateral rectus sheath Deep to umbilicus (contains umbilical ring)

Surface Anatomy

p 135

Aponeurosis

strong sheet of tissue that acts as a tendon to attach muscles to bone Thin, Flat tendon

Superficial Inguinal Ring

triangular opening in the inguinal ligament (external oblique aponeurosis) - Defect in inguinal ligament Above and Lateral to Pubic tubercle Cremaster originates here Ductus Deferens + testicular a. pass through Exits of Inguinal canal