Posterior Abdominal Wall Flashcards
(91 cards)
1
Q
The posterior abdominal wall is mainly composed of:
A
- 5 Lumbar vertebrae + IV discs
- posterior abdominal wall muscles
- diaphragm
- fascia
- lumbar plexus
- fat, nerves, vessels, lymph nodes
2
Q
Posterior abdominal muscles include:
A
- psoas
- quadratus lumborum
- iliacus
- transverse abdominal
- oblique muscles (laterally)
3
Q
What is a marked central prominence in the posterior wall and creates two paravertebral ‘gutters’ on each side of it?
A
lumbar vertebral column
4
Q
The deepest (most posterior) part of the lumbar vertebral ‘gutters’ is occupied by the…?
A
kidneys + their surrounding fat
5
Q
What great vessel lies on the anterior aspect of the anteriorly protruding vertebral column?
A
abdominal aorta
6
Q
In lean individuals, the lower abdominal aorta lies where?
A
close to the anterior abdominal wall
7
Q
Many structures lie anterior to the aorta which may be close to the anterior abdominal wall in thin people. These structures include:
A
- superior mesenteric artery
- parts of the duodenum
- pancreas
- left renal vein
8
Q
The posterior abdominal wall is covered with a continuous layer of _____________? It lies between what two structures/layers?
A
- endoabdominal fascia
parietal peritoneum + the post. ab. muscles
9
Q
The fascia lining the posterior abdominal wall is continuous with what other fascia?
A
transversalis fascia
(lines transverse abdominal muscle)
10
Q
PSOAS FASCIA
A
covers psoas major m. (psoas sheath)
attached medially = lumbar vertebrae + pelvic brim
superiorly = thickened to form medial arcuate ligament
laterally = fuses with quadratus lumborum + thoracolumbar fascias
Inferior (to iliac crest) = continuous with iliac fascia covering iliacus
11
Q
THORACOLUMBAR FASCIA
A
extensive fascial complex
- medially attached to vertebral column
- (lumbar region ) = posterior, middle + anterior layers
(with muscles enclosed between them)
- laterally attached to internal oblique, transverse abdominal, latissimus dorsi
(NOT external obliques)
12
Q
What part of the thoracolumbar fascia is thin + transparent?
What part is thick + strong?
A
thin+transparent = thoracic parts of the deep muscles
thick+strong =** lumbar region**
(lumbar = b/t 12th rib + iliac crest)
13
Q
The anterior layer of the thoracolumbar fascia covers which muscle + is continuous laterally with what structure?
A
COVERS = quadratus lumborum m.
CONTINUOUS W. = aponeurotic origin of transverse abdominal m.
14
Q
ANTERIOR THORACOLUMBAR FASCIA =
A
quadratus lumborum fascia
- thinner, more transparent layer
attachments:
- anterior surfaces of transverse processes of lumbar vertebrae
- iliac crest
- 12th rib
superiorly = thickens to form lateral arcuate ligament
inferiorly = adheres to iliolumbar ligaments
15
Q
The main paired muscles in the posterior abdominal wall (3):
A
- Psoas major (inferolaterally)
- Iliacus (lateral to inferior part of psoas major)
- Quadratus lumborum (lateral to superior part of psoas major)
16
Q
PSOAS MAJOR MUSCLE
(attachment, innervation, action)
A
Attachment:
superior = transverse processes of lumbar vert.; sides of T12-L5 vert. bodies + discs
Inferior = strong tendon to lessor tronchanter of femur
Innervation:
Lumbar Plexus
(anterior L2-L4 spinal n. branches)
Main action:
- acts inferiorly w. iliacus = flexes thigh (standing); flexes trunk (sitting)
- acts superiorly = flexes vertebral column laterally
- balances trunk
17
Q
ILIACUS MUSCLE
(attachment, innervation, action)
A
Attachment:
superior = superior 2/3 of iliac fossa; ala of sacrum; anterior sacroiliac ligaments
Inferior = lesser tronchater of femur + shaft inferior to it; psoas major tendon
Innervation:
Femoral nerve (L2-L4)
Main action:
- flexes thigh
- stabilizes hip joint
- acts w. psoas major
18
Q
QUADRATUS LUMBORUM MUSCLE
(attachments, innervation, actions)
A
Attachment:
superior = medial 1/2 interior border of 12th ribs + tip of lumbar transverse processes
Inferior = iliolumbar ligament + internal lip of iliac crest
Innervation:
anterior branches T12 = L1-L4 spinal n.
Main action:
- extends + laterally flexes vertebral column
- fixes 12th rib (inspiration)
19
Q
The iliopsoas has extensive and clinically important relations to which (8) structures?
When any of these structures is diseased, movement of iliopsoas usually causes pain.
A
- kidneys
- ureters
- cecum
- appendix
- sigmoid colon
- pancreas
- lumbar lymph nodes
- nerves of post. abdominal wall
20
Q
When intra-abdominal inflammation is suspected, what test is performed?
A
iliopsoas test
lie on unaffected side + extend thigh on the affected side against the resistance of the examiner’s hand
- pain with this maneuver is a positive psoas sign
21
Q
Why is it that disease of the intervertebral + sacroiliac joints may cause spasm of the iliopsoas (protective reflex)?
A
because. ..
* *psoas lies along the vertebral column** + iliacus crosses the sacroiliac joint
22
Q
Adenocarcinoma of the pancreas in advanced stages invades the muscles and nerves of the posterior abdominal wall. What symptom does this cause + why?
A
excruciating pain
- b/c close relationship of the pancreas to the posterior abdominal wall
23
Q
Psoas Abscess & Turberculosis:
Prevalence of tuberculosis (TB) has been greatly reduced, but still very present in some areas. TB of the vertebral column is quite common. How is this caused by hematogenous spread, and how does it cause a psoas abcess?
A
- hematogenous spread = infection may spread through blood to the vertebrae
(esp. during childhood)
- TB abscess in lumbar region tends to spread from vertebrae into psoas sheath
= psoas abscess
24
Q
What occurs as a result of a psoas abscess?
A
- psoas fascia thickens + forms strong stocking-like tube
- psoas abscess pus passes inferiorly along psoas muscle in fascial tube, over pelvic brim + deep to inguinal ligament
- pus usually surfaces in the superior part of the thigh
*Pus can also reach psoas sheath from posterior mediastinum when thoracic vertebrae are diseased*
25
**Nerves of the Posterior Abdominal Wall:**
Components of which nervous systems are associated with the posterior abdominal wall?
** somatic** + a**utonomic (visceral)** nervous systems
26
**Nerves of the Posterior Abdominal Wall:**
What path do the subcostal nerves (anterior rami of T12) take to enter the abdomen and reach their target structures?
- arise in the **thorax**
- pass **posterior to lateral arcuate ligaments** into abdomen
- run **inferolaterally** on anterior surface of **quadratus lumborum**
- pass through the **transverse abdominal + internal oblique muscles**
**- _supply_** the *external oblique* + *skin of the anterolateral abdominal wall*
27
Thoracolumbar out-flow =
**Sympathetic** nervous system
28
Craniosaccreal out-flow =
**Parasympathetic** nervous system
29
**Nerves of the Posterior Abdominal Wall:**
What path do the *lumbar spinal nerves (L1 - L5)* take to enter the abdomin and reach their target structures?
- from spinal cord through intervertebral foramina **inferior** to corresponding vertebrae
(divide into posterior + anterior rami)
**sensory + motor fibers**
30
The initial portions of the **anterior rami of the L1, L2, (occasionally L3) **spinal nerves give rise to what structures?
What type of fibers to these convey to the lumbar sympathetic trunks?
- **white communicating branches** (L. rami communicantes)
- convey **presynaptic sympathetic** fibers
* \* L4, L5 have no sympathetic supply therefore no lateral horns\**
31
**Nerves of the Posterior Abdominal Wall:**
The abdominal part of the sympathetic trunks (lumbar sympathetic trunks), consist of 4 ____________ and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_?
These are continuous with the thoracic part of the trunks deep to what structure?
_4 lumbar paravertebral sympathetic ganglia_
+
_interganglionic branches that connect them_
- deep to the **medial arcuate ligaments** of the diaphragm
32
**Nerves of the Posterior Abdominal Wall:**
The lumbar sympathetic trunks descend on what surface of the lumbar vertebrae?
These rest in a groove formed by what adjacent muscle?
**anterolateral aspects** of the **vertebral bodies**
- psoas major
33
**Nerves of the Posterior Abdominal Wall:**
Inferiorly, the lumbar sympathetic trunks cross what structure before continuing inferiorly into the pelvis as the sacral part of the trunks?
cross the **sacral promontory**
34
For the innervation of the abdominal wall + lower limbs, synapses between the **presynaptic and postsynaptic** fibers occur ... (where)?
**Postsynaptic** sympathetic fibers travel from the lateral aspect of the trunks via _______________ to the anterior rami?
- in the **sympathetic trunks**
- via **gray communicating branches**
35
Which nerve fibers become the **thoracoabdominal and subcostal nerves**, and the **lumbar plexus** (somatic nerves)?
What actions do they stimulate in the lowermost trunk and lower limb?
**Postsynaptic sympathetic fibers** from anterior rami
_stimulate:_
**- vasomotion **(stimulates blood vessels)
**- ****sudomotion **(stimulates sweat glands)
**- pilomotion** (stimulates erector pili)
36
What type of nerve fibers are conveyed by the lumbar splanchnic nerves arising from the medial aspect of the lumbar sympathetic trunks?
What do these nerves innervate?
**- presynaptic sympathetic fibers**
- innervate** pelvic viscera**
37
Partial Lumbar Sympathectomy
**surgical removal of two or more lumbar sympathetic ganglia by division of their rami communicantes**
- treatment for some patients with arterial disease in the lower limbs
- surgical access to the sympathetic trunks is commonly through a lateral extraperitoneal approach b/c the sympathetic trunks lie retroperitoneally in the extraperitoneal fatty tissue
38
Buerger’s Disease
| (thromboangiitis obliterans)
**rare disease of the arteries + veins in the arms and legs**
- blood vessels become inflamed, swell + can become blocked with blood clots (thrombi).
- eventually damages/destroys skin tissues + may lead to infection and gangrene inhands + feet
STRONGLY CORRELATED TO SMOKING
***\*\*If you cut sympathetic chain**, you can’t stop process but **can delay the process\*\****
39
**Partial Lumbar Sympathectomy:**
The surgeon splits the muscles of the anterior abdominal wall and moves the peritoneum medially + anteriorly to expose the medial edge of the psoas major (along which the sympathetic trunk lies).
**The left trunk is overlapped slightly by the ...?**
**The right trunk is covered by the ...?**
left = aorta
right = inferior vena cava
40
Partial Lumbar Sympathectomy:
Knowing that identification of the sympathetic trunks is not easy, surgeons take great care not to remove inadvertently part of these (3) structures...?
genitofemoral nerve
lumbar lymphatics
ureter
41
lumbar plexus
**anterior rami of L1 through L4 nerves**
- anterior to lumbar transverse processes, within proximal attachment of the psoas major
_branches of lumbar plexus:_
**- femoral nerve (L2 - L4)\***
**- obturator nerve (L2 - L4)\***
**- lumbosacral trunk (L4, L5)\***
**- ilioinguinal + iliohypogastric nerves (L1)**
**- genitofemoral nerve (L1, L2)**
**- lateral femoral cutaneous nerve (L2, L3)**
**- accessory obturator nerve (L3, L4)**
42
**femoral nerve**
**(L2 - L4)**
- emerges from lateral border of psoas major
- innervates the iliacus + passes deep to inguinal ligament/iliopubic tract to the anterior thigh
**- supplies the flexors of the hip + extensors of the knee**
43
obturator nerve
**(L2 - L4)**
- emerges from medial border of the psoas major
- passes into lesser pelvis, passing inferior to the superior pubic ramus (through the obturator foramen) to the medial thigh
- **supplies the adductor muscles**
44
lumbosacral trunk
**(L4, L5)**
- passes over the ala (wing) of sacrum + descends into the pelvis to participate in the formation of the **sacral plexus with the anterior rami of S1 - S4 nerves**
45
ilioinguinal + iliohypogastric nerves
**(L1) - anterior ramus**
- enter abdomen posterior to medial arcuate ligament
- passes inferolaterally, anterior to the quadratus lumborum
- superior + parallel to iliac crest, piercing the transverse abdominal near the anterior superior iliac spine (ASIS)
- pass through the internal + external obliques to **supply the abdominal muscles + skin of the inguinal and pubic regions**
46
genitofemoral nerve
**(L1, L2)**
- pierces psoas major + runs inferiorly on its anterior surface, deep to the psoas fascia
- divides lateral to common + external iliac arteries into **femoral** and **genital branches**
47
lateral femoral cutaneous nerve
| (lateral cutaneous nerve of the thigh)
**(L2, L3)**
- runs inferolaterally on iliacus + enters the thigh deep to the inguinal ligament/iliopubic tract, just medial to the anterior superior iliac spine
**- supplies skin on anterolateral surface of the thigh**
48
accessory obturator nerve
**(L3, L4)**
**- present almost 10% of the time**
- parallels the medial border of the psoas, anterior to the obturator nerve - crosses superior to superior pubic ramus in close proximity to the femoral vein
49
**The major neurovascular bundle of the inferior trunk includes what structures?**
(It courses in the midline of the posterior abdominal wall, anterior to the bodies of the lumbar vertebrae)
- abdominal aorta
- inferior vena cava
- aortic periarterial nerve plexus
50
Abdominal Aorta
- gives rise to most arteries supplying the posterior abdominal wall
- approximately 13 cm in length
- starts = aortic hiatus in the diaphragm (**T12 vertebra level or 2.5 cm superior to transpyloric plane**)
ends = **L4 vertebra level**; bifutcates into **right + left common iliac arteries**
**-** aortic bifurcation = 2 - 3 cm inferior + left of umbilicus
(@ level of iliac crests)
51
common iliac arteries
| (right + left)
- diverge + run inferolaterally
(follow medial border of the psoas muscles to pelvic brim)
- each common iliac artery divides into **internal + external iliac arteries**
52
internal iliac artery
(branch of right/left common iliac arteries)
- enters the pelvis
- artery for the lower limb!
53
external iliac artery
(branch of left/right common iliac arteries)
- follows the iliopsoas muscle
- before leaving abdomen, gives rise to **inferior epigastric** and **deep circumflex iliac arteries** (supply the anterolateral abdominal wall)
54
The branches of the descending (thoracic and abdominal) aorta may be described as arising and coursing in \_\_\_\_\_\_\_\_\_(#) vascular planes ?
They are classified as being ________ or __________ and
\_\_\_\_\_\_\_\_\_\_\_ or \_\_\_\_\_\_\_\_\_?
- three vascular planes
visceral or parietal; paired or unpaired
55
Paired parietal branches of the aorta serve the what structures?
(2)
diaphragm
posterior abdominal wall
56
What unpaired parietal branch may be said to occupy a fourth (posterior) plane because it arises from the posterior aspect of the aorta just proximal to its bifurcation?
median sacral artery
57
The median sacral artery could be considered a midline \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_?
continuation of the aorta
(in which case its lateral branches, **small lumbar arteries,** and **lateral sacral branches**, would be included as part of the paired parietal branches)
58
Branches of the Abdominal Aorta:
## Footnote
**CELIAC ARTERY**
**_Vascular Plane:_**
anterior midline
**_Class:_**
unpaired visceral
**_Distribution:_**
alimentary tract
**_Vertebral Level:_**
T12
59
Branches of the Abdominal Aorta:
## Footnote
** SUPERIOR MESENTERIC ARTERY**
**_Vascular Plane:_**
anterior midline
**_Class:_**
unpaired visceral
**_Distribution:_**
alimentary tract
**_Vertebral Level:_**
L1
60
Branches of the Abdominal Aorta:
## Footnote
**INFERIOR MESENTERIC ARTERY**
**_Vascular Plane:_**
anterior midline
**_Class:_**
unpaired visceral
**_Distribution:_**
alimentary tract
**_Vertebral Level:_**
L3
61
Branches of the Abdominal Aorta:
** SUPRARENAL ARTERY**
**_Vascular Plane:_**
lateral
**_Class_**:
paired visceral
**_Distribution_**:
urogenital + endocrine organs
**_Vertebral Level:_**
LI
62
Branches of the Abdominal Aorta:
## Footnote
**RENAL ARTERY**
**_Vascular Plane:_**
lateral
**_Class:_**
paired visceral
**_Distribution:_**
urogenital + endocrine organs
**_Vertebral Level:_**
LI
63
Branches of the Abdominal Aorta:
## Footnote
**GONADAL (TESTICULAR or OVARIAN) ARTERY**
**_Vascular Plane:_**
lateral
**_Class:_**
paired visceral
**_Distribution:_**
urogenital + endocrine organs
**_Vertebral Level:_**
L2
64
Branches of the Abdominal Aorta:
## Footnote
**SUBCOSTAL ARTERY**
**_Vascular Plane:_**
posterolateral
**_Class:_**
paired parietal (segmental)
**_Distribution:_**
diaphragm + body wall
**_Vertebral Level:_**
L2
65
Branches of the Abdominal Aorta:
## Footnote
**INFERIOR PHRENIC ARTERY**
**_Vascular Plane:_**
posterolateral
**_Class:_**
paired parietal (segmental)
**_Distribution:_**
diaphragm + body wall
**_Vertebral Level:_**
T12
66
Branches of the Abdominal Aorta:
## Footnote
**LUMBAR ARTERY**
**_Vascular Plane:_**
posterolateral
**_Class:_**
paired parietal (segmental)
**_Distribution:_**
diaphragm + body wall
**_Vertebral Level:_**
L1-L4
67
What pathology may cause the pancreas or stomach to transmit pulsations of the aorta that could be mistaken for an abdominal aortic aneurysm?
**a tumor of the pancreas or stomach **
(because the aorta lies posterior to them)
68
Deep palpation of the midabdomen can detect an aortic aneurysm, which usually results from ...?
a congenital or acquired weakness of the arterial wall
69
Pulsations of a large aneurysm can be detected in what area?
What can be used to confirm the diagnosis in doubtful cases?
**- to the left of the midline**
(pulsatile mass can be moved easily from side to side)
- Medical imaging
70
Acute rupture of an abdominal aortic aneurysm is associated with severe pain in what areas?
What is the mortality rate of aortic aneurysms?
the **abdomen** or **back**
## Footnote
**- 90%**
71
How can an aortic aneurysm be surgically repaired?
1. by opening it
2. inserting a prosthetic graft (such as one made of Dacron)
3. sewing the wall of the aneurysmal aorta over the graft to protect it
* \*(now being treated by means of **endovascular catheterization procedures**)*
72
How ca you apply pressure to control bleeding in the pelvis or lower limbs (esp. in children and lean persons)?
(anterior abdominal wall is relaxed)
**- firm pressure on the anterior abdominal wall, over the umbilicus**
- inferior part of the abdominal aorta may be compressed against the body of the L4 vertebra
73
What line is helpful to **identify the site of aortic bifurcation** when examining obese persons in whom the umbilicus is not a reliable surface landmark?
line joining the highest points of the iliac crests
(just to the left of the midpoint)
74
The veins of the posterior abdominal wall are tributaries of the\_\_\_\_\_\_\_\_\_\_\_\_\_\_, except for the left testicular or ovarian vein, which enters the \_\_\_\_\_\_\_\_\_instead.
- inferior vena cava (IVC)
- left renal vein
75
The IVC, the largest vein in the body, has no valves except for \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_?
**non-functional one at its orifice in the right atrium** of the heart
76
The IVC returns poorly oxygenated blood from ...?
lower limbs
most of the back
abdominal walls
abdominopelvic viscera
77
Blood from the abdominal viscera passes through \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ before entering the IVC through the hepatic veins
portal venous system + liver
## Footnote
*\*(non-portal blood collected from abdomen + pelvis) *
78
Where does the IVC begin, ascend, and exit the abdominal cavity?
_begins_ = **anterior to L5** vertebra **@ union of common iliac veins**
*(inferior to the bifurcation of the aorta and posterior to the proximal part of the right common iliac artery)*
_ascends_ = right sides of **L3 - L5 vertebrae bodies** + on **right psoas major** to right of the aorta
_exits_ = thru **caval opening in diaphragm;** enters thorax at **T8** vertebral level
79
The **tributaries** **of the IVC** correspond to the ______________ branches of the abdominal aorta?
The **tributaries of the portal vein** correspond to the ___________ branches of the aorta?
IVC = paired visceral + parietal
portal vein = unpaired visceral
80
The branches of the IVC corresponding to the **paired viscera branches** of the abdominal aorta include ... (4)?
- right suprarenal vein
- right + left renal veins
- right gonadal (testicular or ovarian) vein
81
**Paired parietal branches** of the IVC include ... (4)?
**inferior phrenic veins**
**3rd (L3) + 4th (L4) lumbar veins**
**common iliac veins** *(union of external + internal iliac veins)*
82
Which 2 ascending veins connect the IVC + superior vena cava, either directly or indirectly?
**lumbar veins** and **azygos veins**
83
What are the 3 collateral routes available for venous blood to return to the heart when the IVC is obstructed or ligated?
1. superior + inferior epigastric veins
2. thoracoepigastric vein
3. epidural venous plexus\* (inside vertebral column)
* \*communicates with lumbar veins + tributaries of azygos system*
84
Why are IVC anomalies relatively common?
Where do most of them occur?
- forms from parts of **three sets of embryonic veins**
- inferior to the renal veins
85
In the posterior abdomen, where do lymphatic vessels + lymph nodes lie?
along the **aorta**
along **IVC**
along **iliac vessels**
86
Where do the **common iliac nodes** receive lymph from + where do they drain lymph to?
receive from = **external + internal iliac lymph nodes**
drain to = **right + left lumbar lymph nodes**
87
Efferent vessels from *which lymph nodes* form the **intestinal lymphatic trunks +** participate in the confluence of lymphatic trunks that gives rise to the thoracic duct?
What structures do these lymph nodes receive lymph from?
**celiac, superior + inferior mesenteric nodes**
_receive lymph from:_
- alimentary tract
- liver
- spleen
- pancreas
88
The thoracic duct begins with the convergence of what ducts?
Where is this located?
These form what dialation/structure?
- **main lymphatic ducts** of the abdomen
- anterior to L1 + L2 vertebrae bodies; between right crus of diaphragm + aorta
convergence = the **chyle cistern**
89
Lymphatic drainage from what areas of the body converge in the abdomen to enter the beginning of the thoracic duct?
** all lymphatic drainage from** **lower half of the body**
- deep lymphatic drainage inferior to level of diaphragm
- superficial drainage inferior to level of umbilicus
90
Thoracic duct ascends through the aortic hiatus in the diaphragm into the posterior mediastinum.
It collects more parietal and visceral drainage, particularly from what quadrant?
**left upper quadrant** of the body
91
Where does the thoracic duct end?
ends by entering the venous system at:
## Footnote
**junction of the left subclavian + internal jugular veins**
*(the left venous angle)*
