Exam IV: Abdomen II Flashcards Preview

Anatomy > Exam IV: Abdomen II > Flashcards

Flashcards in Exam IV: Abdomen II Deck (35):

Abdominal Wall: Superficial Fatty Fascia

Superficial Fascia- fatty layer called Camper's fascia with veins that run through it - well vascularized

Male: continuous with dartos fascia of the scrotum.
Female: continuous with superficial fat of the labia majora

As we get closer to the groin region, the fatty layer becomes more membranous
Dartos fascia is a layer under the skin that passes through the scrotum; is another name for superficial fascia
Superficial in abdomen is Camper’s, but groin area is called Dartos


Abdominal Wall: Superficial Membranous Fascia

Superficial fascia: deep layer is membranous that covers the muscles
Thigh: fascia lata
Perineum: superficial perineal fascia
Fundiform ligament

Deep superficial fascia is continuous with the thigh and peritoneum, called fascia lata in the thigh
Coming down from the abdomen to the clitoris or penis = forms the fundiform ligament
For males/females: comes down and splits over the penis/clitoris to support and strengthen both sides


External Oblique

Attachment: outer surface of the lower 8 ribs (ribs V to XII) and lateral iliac crest aponeurosis ending in midline (linea alba)

Innervation: anterior rami of lower 6 thoracic spinal nerve (T7 to T12)

Function: compress abdominal contents
Both muscles- flex trunk
Each side- bend trunk and turn anterior part to opposite side

Orientation of the muscle: lateral superior to medial inferior “hands in pockets”


External Oblique Ligaments: Inguinal and Lacunar

Associated ligaments- External Oblique

Inguinal ligament: inferior border of aponeurosis of external oblique
Lacunar ligament: extension off of inguinal ligament and attaches to the pectin pubis (pubic bone)


External Oblique: Pectin Pubis and Pectineal Ligament

Pectin pubis
Pectineal ligament
Pectineal line with the ligament associated with it to provide support


Internal Oblique

Attachments: thoracolumbar fascia, iliac crests, lateral 2/3 of inguinal ligament, inferior border of lower 3 or 4 ribs, aponeurosis ending in linea alba, pubic crest and pectineal line

Innervation: anterior rami of lower 6 thoracic spinal nerves (T7 to T12) and L1

Function: compression of abdominal contents
Both muscles- flex trunk
Each site- bend trunk and turn anterior part to same side


Transversus Abdominis

Attachment: thoracolumbar fascia, medial lip of iliac crest, lateral 1/3 of inguinal ligament, costal cartilage of lower 6 ribs (ribs VII to XII), aponeurosis ends in linea alba, pubic crest and pectineal line

Innervation: anterior rami of lower 6 thoracic spinal nerves and L1

Function: compresses abdominal contents


Rectus Abdominis

Attachments: pubic crest, pubic tubercle, pubic symphysis, costal cartilage or rib V to VII, xiphoid process

Innervation: anterior rami of lower six or seven throacic spinal nerves (T6~ T7 to T12)

Function: compress abdominal contents, flex vertebral column, tense abdominal wall

Anterior muscle “6 pack"



Attachments: front of the pubis, pubic symphysis, linea alba

Innervation: anterior ramus of T12

Function: tenses the linea alba

Very tiny muscle – 3-3.5 inches


Rectus Sheath

Aponeurotic tendinous sheath formed by a unique layering of the aponeurosis of the external and internal obliques and transversus abdominis muscles

Depending on the location in the abdomen:
The muscles go in different directions
All muscles fuse anteriorly = forms the arcuate line where all of a sudden all the aponeurosis go in front

Aponeurosis went from being behind to being in front= arcuate line and turn into the transversalis fascia instead of rectus sheath


Abdominal Wall Layers

Superficial fascia: fatty layer + deep membranous layer
External oblique
Internal oblique
Transversus abdominis
Transversalis fascia
Extra peritoneal fascia
Parietal peritoneum


Functions of Anterior Abdominal Muscles

1. Curvature of waist: external and internal oblique form a “girdle”

2. Rotation: external oblique vs internal oblique
Mechanical efficiency increased by fiber direction in each layer
Synergistic – e.g. rotation to left contraction of rt. External oblique and left internal oblique

3. Flexion: powerful because of lever action

4. Lumbar curvature: depends on abdominal and paravertebral muscle + lower back muscles
Relaxed muscles accentuates all 3 curvatures, e.g. posture of elderly because they are not counteracting the back muscles if they are relaxed/weakened
Forward tilt of pelvis counteracted by rectus abdominis.


Innervation of the Abdomen: Cutaneous Branches

T6 – xiphoid
T10 – umbilicus
T11, T12, L1 – below umbilicus
L1- scrotum/labia majora and thigh

Spinal nerves are passing cutaneous branches running deep to the skin- run on top of the external oblique muscles
Give us our dermatome pattern


Innervation of the Abdomen: Muscular Branches

T7 to T12 passes between internal oblique and transversus
L1 passes between internal oblique and external oblique (does not innervate rectus abdominis)

Autonomic nerves: T5-L2 is where they originate from; delivering them from skin and muscles via mixed GVA, GVE, GSA, GSE… no parasympathetic, which only innervates blood vessels


Blood Supply

Internal thoracic artery: musculophreic and superior epigastric both following the costal margin

Aorta: lower intercostal and T12/subcostal artery

External iliac artery: inferior epigastric and deep circumflex iliac; supplies abdominal wall and lower limb
Inferior epigastric is the landmark to define hernia types
Deep circumflex artery: deep and runs across the iliac crest and supplies the iliacis muscle as well as muscles attached to iliac crest

Femoral artery: superficial circumflex iliac and superficial epigastric


Superficial Drainage

Superficial veins:
Above umbilicus → axillary v.
Below umbilicus → femoral v.
Paraumbilical vein- get backed up and pressure= capitis medusa formation

Superficial lymph vessels:
Above umbilicus → anterior axillary nodes
Below umbilicus → superficial inguinal nodes


Venous and Lymphatic Drainage

Deep veins: follow the arterial pattern

Deep lymph vessels: follow the deep arteries → parasternal nodes , lumbar nodes, and external iliac nodes


Groin: Descent of Gonads

Processes vaginalis and descent of gonads into scrotum/labrum majora
External oblique, internal oblique, transversus abdominis, transversalis, testes and gubernaculum = layers
When gonads descend, the muscle layers descend with it and contribute to surrounding scrotum musculature
Ovaries to pelvis or testes to scrotum
We don’t want abdominal contents to go into the scrotum so need to close it off after descent or inguinal hernia can occur


Inguinal Canal

Consequences of testes movement outside of the abdominal cavity in scrotum
Position of blood vessels and nerves of testis pass from abdominal cavity, through inguinal canal into scrotum
Ovaries become located in pelvis
Carries layers of anterior abdominal wall forward to form spermatic cord and round ligament
Oblique path remains in anterior abdominal wall through which gubernaculum and testes passed (inguinal canal)


Deep Inguinal Ring

Deep inguinal ring
Transversalis fascia → internal spermatid fascia (male) and Inner layer (female)
Lateral to epigastric vessels
Superficial to connective tissue layer (extra peritoneal fat) and peritoneum

First structure: deep inguinal ring- opening on inside of abdomen where structures that pass through spermatic cord go through and formed via transversalis fascia, which is the innermost layer of spermatid fascia for males and inner layer for females
Deep inguinal ring occurs lateral to the epigastric artery
Peritoneum gets drawn in and remains


Superficial (Exterior) Inguinal Ring

Superficial (external) inguinal ring consists of:
1. External oblique aponeurosis with spermatic cord passing through

2. Crura:
Lateral crus – lateral side of superficial ring
Medial crus – medial side of superficial ring

3. Inguinal ligament – folded inferior border of external oblique

4. Forms external spermatic fascia of spermatic cord/round ligament


Borders of the Inguinal Canal

Anterior Wall: external oblique aponeurosis

Lateral wall: internal oblique muscle, which forms cremaster fascia and muscle / fascia of spermatic cord/round ligament 

Posterior wall: transversalis fascia (full length) and conjoint tendon (medial 1/3)  

Roof: formed by the arching fibers of the transversus abdominis and internal oblique muscles

Floor: inguinal ligament


Spermatic Cord

Ductus/ Vas deferens- passes through spermatic cord
Artery to the ductus deferens (branch from inferior vesical artery)
Testicular artery (from the abdominal aorta)
Pampiniform plexus and veins (testicular vein)
Cremasteric artery and vein (small vesicles associated with cremasteric fascia)
Genital branch of the genitofemoral nerve (innervation to the cremasteric muscle)
Sympathetic and visceral afferent nerve fibers
Remnants of the processus vaginalis


External Oblique Aponeurosis

makes the:
Spermatic Cord/Male: external spermatic fascia

Round Ligament/ Female: outer layer


Internal Oblique Muscle

makes the:
Spermatic Cord/ Male: cremaster fascia and muscle

Round Ligament/ Female: diminishes from proximal to distal


Transversalis Fascia

makes the:
Spermatic Cord/Male: internal spermatic fascia

Round Ligament/Female: inner layer


Superior Vesicle Artery

makes the:
Spermatic Cord/Male: ductus deferens artery



makes the:
Spermatic Cord/Male: testicular artery

Round Ligament/Female: ovarian artery


Right: Inferior Vena Cava
Left: Left Renal Vein

makes the:
Spermatic Cord/Male: pampiniform plexus

Round Ligament/Female: ovarian vein


L1 and L2

makes the:
Spermatic Cord/Male: genitofemoral nerve

Round Ligament/Female: genitofemoral nerve


Genital Branch in Inguinal Canal

makes the:
Spermatic Cord/Male: cremasteric muscle innervation

Round Ligament/Female: supplies round ligament


Femoral Branch

makes the:
Spermatic Cord/Male: sensory medial thigh

Round Ligament/Female: sensory medial thigh


Ilioinguinal Nerve from L1

makes the:
Spermatic Cord/Male: prosimomedial aspect of thigh + perineal region

Round Ligament/Female: prosimomedial aspect of thigh + perineal region


Inguinal/Hasselbach's Triangle

Rectus abdominis, epigastric vessels, inguinal ligament forms the borders
Lateral to that is the deep inguinal ring


Inguinal Hernias

1. Indirect: goes through deep inguinal ring; more common congenital condition; if you have one hernia on one side probably have it on the other side as well and need to fix both
Indirect + elderly = inferior epigastric vessels are the key!
Lateral to epigastric vessels: deep inguinal ring down to spermatic cord

2. Direct: people that have weak abdominal wall muscles, or older men predominantly
Women can get both as well
Medial to epigastric vessels: inguinal/Hassalbach’s triangle (DOES NOT GO THROUGH the deep inguinal ring)