Abdomen Week 1 (B) Flashcards
What is the arterial supply of the abdomen? (9)
STUDY
Arterial supply on a cadaver:
What is the venous drainage in the abdomen?
▪ Intricate subcutaneous venous plexus
What are the main veins? (2)
▪Para-umbilical veins→hepatic portal vein laterally:thorax tabdom en
▪Thoraco-epigastric vein (not always present)
Venous drainage
Superiorly: (2)
Venous drainage
Inferiorly: (2)
Venous drainage
▪Deep veins follow _____
▪Deeper _______ may exist
arteries
anastomoses
Nervous supply of the abdomen: (5)
Lymphatics:
▪Superficial lymphatic vessels→ superficial veins
▪NB! Transumbilical line
▪ Superior :
▪ Inferior :
axillary nodes (parasternal
nodes)
superficial inguinal nodes
▪Deep lymphatic vessels→ deep veins
▪ Drain into….
external iliac, common iliac,
right and left lumbar nodes.
Clinical Significance: Fascia and Spaces
▪ Membranous layer of fascia:
▪ Included in suturing below umbilicus (therefore tough layer of fascia; keeps wound closed + attached)
Clinical Significance: Fascia and Spaces
▪ Between membranous and deep fascia: (2)
▪ Fluid can accumulate
▪ Cannot spread into thigh (Scarpa’s terminates above thigh - continuous in perineum but not thigh)
Clinical Significance: Fascia and Spaces
▪ Between membranous and deep fascia:
▪ Fluid can accumulate
▪ Cannot spread into thigh
Clinical Significance: Fascia and Spaces
▪ Endoabdominal fascia
▪ Surgical plane of opening ≠ abdominal cavity
- For incisions
Clinical Significance: Abdomen Protrusion
Common causes: (6)
▪Food
▪ Fluid
▪ Flatus ~gas build up in GIT
▪ Faeces
▪Fat
▪ Foetus
Clinical Significance: Abdomen Protrusion
▪Umbilicus eversion→ ______ or large mass
▪ In underdeveloped or weak muscles→
abdomen can become _______ (abdomen wall can’t maintain viscera posteriorly)
ascites
protruded
Neurovasculature
Dermatomes:
- Anterior rami of T7-T12 and L1
Thoraco-abdominal
Dermatomes:
Origin:
T7-T11
Continuation of 7th – 11th intercostal nerves distal to the costal margin
7th – 9th lateral cutaneous br.
Dermatomes:
Origin:
T7-T9
Anterior divisions of 7th - 9th intercostal nerves
Subcostal nerve
Dermatomes:
Origin:
T12
Anterior ramus of T12
Iliohypogastric nerve
Dermatomes:
Origin:
L1
Superior terminal branch of anterior ramus of L1
Ilio-inguinal nerve
Dermatomes:
Origin:
L1
Inferior terminal branch of anterior ramus of L1
Superficial veins:
T7 - T9:
skin superior to umbilicus
T10:
skin around umbilicus
T11-L1:
skin inferior to umbilicus
L1:
inguinal fold
Referred pain:
T10 from appendix
Which veins make up the subcutaneous venous plexus?
Lymph drainage
* Superficial vessels above transumbilical plane: (2)
o Axillary lymph nodes
o Parasternal lymph nodes
Lymph drainage:
* Superficial vessels below transumbilical plane
o Superficial inguinal lymph nodes
Lymph drainage:
Deep vessels (4)
Lymph drainage:
Deep vessels (4)
Musculophrenic
Origin:
Course:
Supply:
Internal thoracic
Descends along costal margin
Hypochondrium
Anterolateral diaphragm
Superior epigastric
Origin:
Course:
Supply:
Internal thoracic
Descends in rectus sheath deep to rectus abdominis
Rectus abdominis m.
Epigastric and upper umbilical regions
10th & 11th posterior intercostal
Origin:
Course:
Supply:
Aorta
Descends between internal oblique and transversus abdominis
Lateral (lumbar) region
Subcostal
Origin:
Course:
Supply:
Aorta
Descends between internal oblique and transversus abdominis
Lateral (lumbar) region
Inferior epigastric
Origin:
Course:
Supply:
External iliac
Ascends in rectus sheath deep to rectus abdominis
Rectus abdominis m.
Deep pubic & lower umbilical regions
Deep circumflex iliac
Origin:
Course:
Supply:
External iliac
Runs parallel to inguinal ligament deep in anterior abdominal wall
Iliacus m.
Deep inguinal region & iliac fossa
Superficial circumflex iliac
Origin:
Course:
Supply:
Femoral
Runs in subcutaneous tissue along the inguinal ligament
Superficial inguinal region
Adjacent anterior thigh
Superficial epigastric
Origin:
Course:
Supply:
Femoral
Runs in subcutaneous tissue toward umbilicus
Superficial pubic & lower umbilical regions
What is the Internal Anterolateral Abdominal Wall?
- Covered with transversalis fascia, extraperitoneal fat and parietal peritoneum
What are * Umbilical peritoneal folds? (2)
o Folds on the infra-umbilical part of the internal surface of the anterolateral abdominal wall
o 2 on each side and 1 in the median plane
What is the o Median umbilical fold? (2)
- Apex of bladder to umbilicus
- Covers median umbilical ligament
- Remnant of urachus
What are the o Medial umbilical folds? (2)
- Lateral to the median umbilical fold
- Cover medial umbilical ligaments
- Obliterated umbilical aa.
What are the o Lateral umbilical folds? (2)
- Lateral to the medial umbilical folds
- Cover the inferior epigastric vessels
What are the * peritoneal fossae? (2)
o Depressions lateral to umbilical folds
o Potential sites for hernia
o Supravesical fossa- (2)
- Between median and medial umbilical folds
- Level rises and falls with filling of bladder
o Medial inguinal fossa- (3)
- Between medial and lateral
umbilical folds - AKA inguinal triangle
- Potential site for direct
inguinal hernias
o Lateral inguinal fossa- (3)
- Lateral to the lateral umbilical folds
- Include the deep inguinal ring
- Potential sites for indirect
inguinal hernia
What is the inguinal region?
From anterior superior iliac spine to pubic tubercle
What is the anatomical importance of the inguinal region?
Many structures enter/exit abdominal cavity through this area
What is the clinical importance of the inguinal region?
Hernias
Inguinal region
- Inguinal canal
Pathway for testes _____
descent
What is the iliopubic tract?
Thickened tranverse fascia
What is the inguinal ligament?
Originates from thickened external oblique aponeurosis.
Where is the iliopubic tract located?
▪From anterior superior iliac spine
to pubic tubercle
How is the flexor retinaculum formed?
Formed by 2x structures
What is the function of the flexor retinaculum?
Maintains structure against skeleton while joints move
What is contained in the subinguinal space? (2)
- Flexors of the hip
- Neurovasculature
What are the flexors of the hip? (3)
- iliacus
- psoas major
- pectineus
Neurovasculature in the subinguinal space: (2)
- femoral n.a.v
- lat cut n. of thigh
Neurovasculature in the subinguinal space: (2)
- femoral n.a.v
- lat cut n. of thigh
Where does the inguinal ligament attach?
▪Attach on pubic tubercle mostly
Inguinal ligament:
Deep fibres –> ____ ligament = medial boundary of _____ space
lacunar
subinguinal
Inguinal ligament
Superior fibres –> ______ inguinal ligament
reflected
What is the iliopubic tract? (3)
▪Fibrous band parallel to inguinal ligament
▪Posterior to inguinal ligament
▪Thickened transversalis fascia
Where can the iliopubic tract be seen?
▪ Can be seen following inguinal ligament internally
What is the function of the iliopubic tract?
▪Reinforce posterior wall and floor of inguinal canal
▪ With the inguinal ligament protect myopectinal orifice→
site for hernias
When does the inguinal canal form?
▪ Forms during development for the descent of the testis
How long is the inguinal canal?
▪Oblique passage ≈ 4cm long
What does the inguinal canal lie parallel to?
▪ Parallel to inguinal ligament
What are the main contents of the inguinal canal? (2)
▪ Spermatic cord (males)
▪ Round ligament of the uterus (females)
Inguinal canal
▪ Also contains ________
▪ Delimited by _____ and deep inguinal rings
neurovasculature
superficial
What are inguinal rings? (2)
▪ Deep inguinal ring
▪ Superficial inguinal ring
What is the deep inguinal ring?
Entrance into canal
What is the location of the deep inguinal ring? (2)
▪ Superior to inguinal ligament midpoint
▪ Lateral to inferior epigastric artery
▪ Deep inguinal ring:
▪ Evagination of the transversalis fascia →
inner covering of canal
▪ Deep inguinal ring:
▪ Passage of _____ cord contents or round ligament of uterus
spermatic
What is the superficial inguinal ring? (2)
▪ Exit for canal contents
▪ Separation of parallel fibres of external oblique aponeurosis
Where is the superficial inguinal ring located?
▪ Superolateral to pubic tubercle
Inguinal ring
▪ Aponeurosis parts form the crura
▪ Lateral crus →
▪ Medial crus →
pubic tubercle
pubic crest
Pubic crest + pubic tubercle =
Intercrural fibres
What are the boundaries of the inguinal canal? (4)
- Anterior wall
- Posterior wall
- Roof
- Floor
Inguinal canal
Anterior wall: (2)
▪ External oblique aponeurosis
▪ Internal oblique muscle fibres (lateral)
Inguinal canal
Posterior wall: (3)
▪ Transversalis fascia
▪ Pubic attachment of internal oblique and transversus abdominis aponeuroses = inguinal falx (medial)
▪ Inguinal ligament (reflection)
Inguinal canal
Roof: (3)
▪ Transversalis fascia (lateral)
▪ Transversus abdominis and internal oblique (central)
▪ Medial crus of external oblique (medial)
Inguinal canal:
Floor (3)
▪ Iliopubic tract (lateral)
▪ Inguinal ligament (central)
▪ Lacunar ligament (medial)
READ
Inguinal canal: Contents
Male (9)
Inguinal canal: Contents
Female (2)
Inguinal canal: Contents
Female (2)
Inguinal canal: Contents
All sexes (2)
▪ Blood and lymphatic vessels
▪ Ilio-inguinal nerve
How does the inguinal canal develop in males? (2)
▪ Testes on posterior abdominal wall week 28 embryo (7th month) inwayof peitanium
▪ Processus vaginalis of peritoneum passes through transversalis fascia to form inguinal canal
How does the inguinal canal develop? (2)
▪ Testes on posterior abdominal wall week 28 embryo (7th month) inwayof peitanium
▪ Processus vaginalis of peritoneum passes through transversalis fascia to form inguinal cana
What is
What is the gubernaculum?
▪ Gubernaculum pulls testis inferiorly into scrotum
→ ligament
Inguinal canal: development (male)
- Testis posterior to processus ____
- Processus vaginalis forms ____ vaginalis
vaginalis
tunica
How does the inguinal canal develop in females? (2)
▪ Ovaries on superior ______ region (post
abdominal wall)
▪ Processus vaginalis forms inguinal canal
What is the function of the gubernaculum in females?
▪ Gubernaculum connects ovary to uterus to anterior abdominal wall→ovarian ligament and round ligament of uterus
Male contents:
- Ductus deferens (vas deferens) =
- Testicular artery =
- Artery of ductus deferens =
- Cremasteric artery =
- Pampiniform venous plexus =
- Sympathetic nerve fibres =
- Genital branch of genitofemoral nerve =
- Lymphatic vessels =
- Vestige of processus vaginalis =
What happens to the processus vaginalis at 15 weeks?
At 15 weeks, the ovaries have descended into the greater pelvis. The processus vaginalis (not shown) passes through the abdominal wall, forming the inguinal canal on each side as in the male fetus. The round ligament passes through the canal and attaches to the subcutaneous tissue of the labium majus.
What is the pressure of intrabdominal pressure? (7)
How is the canal constricted?
Contraction of musculature that forms the lateral part
of the arcades of the internal oblique and transversus abdominis muscles makes the roof of the canal descend, constricting the canal.
What are the problems associated with the inguinal canal and intrabdominal pressure? (2)
Where do majority of hernias occur?
The majority of abdominal hernias occur in the inguinal region. Inguinal hernias account for 75% of abdominal hernias. These herniations occur in both sexes, but most inguinal hernias (approximately 86%) occur in males because of the passage of the spermatic cord through the inguinal canal.
What is an inguinal hernia?
An inguinal hernia is a protrusion of parietal peritoneum and viscera, such as the small intestine, through a normal or abnormal opening from the cavity in which they belong. Most hernias are reducible, meaning they can be returned to their normal place in the peritoneal cavity by appropriate manipulation. The two types of inguinal hernia are direct and indirect inguinal hernias. More than two thirds are indirect hernias.
What is the inguinal region? (2)
- AKA groin
- Extends between anterior superior iliac spine and pubic tubercle
Inguinal Region-
* Bilaminar flexor retinaculum of the hip joint: (3)
o Formed by inguinal ligament and iliopubic tract
o Extends from anterior superior iliac spine to pubic tubercle
o Spans the Subinguinal space (lacunar ligament forms medial boundary)
Inguinal Region-
Inguinal ligament:
o Dense band constituting inferior most part of the external oblique aponeurosis
Inguinal ligament
Insertion:
Fibres:
Pubic tubercle
Most fibres
Lacunar ligament
Insertion:
Fibres:
Superior pubic ramus
Deeper fibres passing posteriorly
Lacunar ligament
Insertion:
Fibres:
Superior pubic ramus
Deeper fibres passing posteriorly
Pectineal ligament
Insertion:
Fibres:
Pecten pubis
Lateral deeper fibres
Reflected inguinal ligament
Insertion:
Fibres:
Contralateral external oblique aponeurosis
Superior fibres fanning upward
What is the iliopubic tract? (3)
What is the iliopubic tract? (3)
Where is the inguinal canal located? (2)
- Oblique passage 4cm long directed inferomedially
- Lies parallel and superior to the medial half of the inguinal ligament
What are the openings of the inguinal canal? (2)
- Deep (internal) inguinal ring
- Superficial (external) inguinal ring
What are the features of the * Deep (internal) inguinal ring? (4)
What are the features of the superficial (external) inguinal ring? (3)
Lateral crus attaches to…
Medial crus attaches to…
§ Lateral crus- attaches to the pubic tubercle
§ Medial crus- attaches to the pubic crest
Inguinal canal boundaries
Posterior wall
Lateral third/deep ring:
Middle third:
Medial third/superficial ring:
Transversalis fascia
Transversalis fascia
Conjoint tendon and reflected inguinal ligament
Inguinal canal boundaries
Anterior wall
Lateral third/deep ring:
Middle third:
Medial third/superficial ring:
Internal oblique & lateral crus
Lateral crus and intercrural fibres
Intercrural fibres and external spermatic fascia
Inguinal canal boundaries
Roof
Lateral third/deep ring:
Middle third:
Medial third/superficial ring:
Transversalis fascia
Musculo-aponeurotic arches of internal oblique and transversus abdominis
Medial crus
Inguinal canal boundaries
Floor
Lateral third/deep ring:
Middle third:
Medial third/superficial ring:
Iliopubic tract
Inguinal ligament
Lacunar ligament
Inguinal canal boundaries
Floor
Lateral third/deep ring:
Middle third:
Medial third/superficial ring:
Iliopubic tract
Inguinal ligament
Lacunar ligament
Inguinal canal contents
Male AND female (3)
In both male and female
* Ilioinguinal n.
* Sympathetic nn.
* Lymphatics
Inguinal canal contents
Female
- Round ligament of
uterus
Inguinal canal contents
Male (4)
Inguinal canal contents
Male (4)
What is a hernia?
Infolding of small/large intestine; forms pouch of peritoneum that pushes through ant. abdomen wall.
Direct vs indirect inguinal hernia:
A direct inguinal hernia shows a bulge from the posterior wall of the inguinal canal, whereas an indirect inguinal hernia passes through the inguinal canal or the groin. In the indirect inguinal canal, it is difficult to feel the defect as it occurs behind the external oblique muscle fibres.
What are the features of an indirect inguinal hernia? (3)
What are the features of a direct inguinal hernia? (2)
What are the features of a femoral hernia? (2)
What are abnormal hernias? (2)
- Abnormal protrusion of a structure through tissues which normally contain it
- Most commonly in the inguinal, femoral, umbilical and epigastric regions.
Indirect vs Direct inguinal hernias: (6)
What is a femoral hernia? (5)
Anatomical features of inguinal canal that minimize herniation: (5)
Anatomical features of inguinal canal that minimize herniation: (5)
