S2 Anatomy Exam 1: Post. Abdominal Wall & Diaphram

Front 1

Obj.
Name the bony parts of the posterior abdominal wall

Back 1

lumbar vertebrae (L1-L5)
sacrum
ilium
ribs XI -XII

Front 2

Obj.
Muscles of the posterior abdominal wall:

Back 2

Psoas minor
Psoas major
Iliacus
Quadratus lumborum
Diaphragm

Front 3

Name the viscera associated w/ the posterior abdominal region

Back 3

kidneys
ureter
adrenal glands

Front 4

Obj.
Psoas major attachment & action

Back 4

Origin: T12 to L5
Insertion: Lesser trochanter of femur
action: flexion of thigh at hip

-Innervation – posas major: lumbar plexus (L1-3)

Front 5

Obj
Psoas minor attachment & action

Back 5

Origin: lateral surface of T12-L1 & L4 discs
Insertion: pectineal line & iliopubic prominence
action: weak flexion of vertebral column

-Innervation: lumbar plexus (L1)

Front 6

In the case of a psoas abscess, infection spreads from interbertebral discs to psoas sheath. Where will pus accumulate?

Back 6

beneath inguinal ligament

Front 7

Obj.
Iliacus proximal attachment & action

Back 7

Origin: superior 2/3 of iliac fossa, ant sacro-iliac & iliolumbar ligaments, & upper lateral sacrum
Insertion: joins psoas major to form ilipsoas & insert into lesser trochanter of femur
action: stabalizes hip joint, flexes thigh w/ psoas major

-Innervation: lumbar plexes (femoral nerve (L2 – L4)

Front 8

Obj.
Quadratus lumborum attachment & action

Back 8

Origin: Iliac crest & iliolumbar ligament, transverse process of L5
Insertion: inferior border of 12th rib and transverse processes of L1-4
action: some lateral bending of trunk; depresses/fixes rib 12 during respiration

- Innervation: Lumbar plexus (T12 – L4)

*overlapped medially by psoas major, transversus abdominis on lateral border

Front 9

Abdominal Aortic Aneurysm is a surgical emergency. At what level do the majority occur?

How can they be treated?

Back 9

Majority at level of renal arteries, large amount extend into illiac arteries

Aortic stent graft, incision made in femoral artery, graft extended into common illiac

Front 10

Obj.
(Describe fascial lining of post abd wall)
Layers of thoracolumbar fascia

Back 10

- Note anterior, middle and posterior layers of the thoracolumbar fascia and which muscles or groups of muscles they enclose.

- Lateral attachment of posterior layer to the internal oblique and transversus abdominis mm.

- Note psoas fascia and renal fascia

Front 11

Obj.
Diaphragm location & function

Back 11

Floor of thoracic cavity
Roof of abdominal cavity
R & L dome – Right side is higher (5th rib, L only to 5th ICS) because of the liver


location: central tendon and out from xiphoid process, costal cartilages of lower 6 ribs, ant surface of lumbar vertebrae & discs, ant longitudinal ligament

function:

Front 12

Obj.
Major openings of the diaphragm, their vertebral levels, & structures

Back 12

allow structures to pass from the thoracic cavity into the abdominal cavity

Diaphragmatic apertures:
- Caval opening – IVC, right phrenic nerve, T8

- Esophageal hiatus – esophagus, esophageal branches of L gastric a. & v., and ant/post vagal trunks, T10

- Aortic hiatus – descending aorta and thoracic duct, T12

-sternocoastal hiatus- superior epigastric artery, through foramen of Morgagni
* greater & lesser thoracic splanchnic nerves, sympathetic trunks, least splanchnic nerves, left phrenic n, & subcostal nerves also pierce through diaphragm

Front 13

Obj.
Innervation Diaphram

Back 13

- Motor (efferent) innervation is from phrenic nerve (C3-5) only

-Sensory:
Phrenic nerve also has general somatic afferent (proprioception and pain) fibers.

- On the periphery of the diaphragm GSA fibers are located within lower 6 intercostal nerves and subcostal nerves T5-12)

Front 14

Describe referred pain from diaphram

Back 14

1. Referred pain from the periphery of diaphragm can felt over costal margins of anterolateral abdominal wall (bc supplied by inferior intercostal n)
2. Referred pain from diaphragmatic pleura/peritoneum is felt in shoulder region
-R shoulder: inflamed gallbladder, liver abscess, hepatorenal recess abscess
-L shoulder: pancreatitis, splenic rupture

Front 15

Obj.
Lymphatic drainage of diaphram

Back 15

Thoracic Surface:
Anterior Diaphragmatic nodes- drain parasternal lymph nodes & some abdominal vessels
Posterior diaphragmatic nodes- drain phrenic & posterior mediastinal nodes
*Parasternal & posterior mediastinal nodes drain into bronchomediastinal trunks & thoracic duct (L) or R lymphatic duct

Abdominal Surface:
Phrenic nodes & Superior lumbar (caval/aortic) nodes--> both drain into thoracic duct

Front 16

Paradoxical Movement

Back 16

-If one phrenic nerve is damaged then paralysis of half the diaphragm (hemi diaphragm) on the ipsilateral side results and eventual muscular atrophy will ensue.

- A paralyzed hemidiaphragm cannot contract, i.e. descend, so it will be positioned higher than normal in the thorax when viewed on a chest radiograph. (may be asymptomatic)

Front 17

Arcuate ligaments

Back 17

are thickenings of fascia that serve as attachments for fibers of the diaphragm

- Lateral arcuate lig. is a superior thickening of the anterior layer of thoracolumbar fascia (around quadratus lumborum).

- Medial arcuate lig. is a superior thickening of the psoas fascia.

Front 18

Obj.
Diaphragm blood supply via:

Back 18

Superior surface:
Superior phrenic arteries (from thoracic aorta)

Pericardiophrenic arteries (from internal thoracic a.)

Musculophrenic arteries (from internal thoracic a.)

Inferior surface:
Inferior phrenic arteries (from abdominal aorta)

Front 19

Diaphragm Venous drainage:

Back 19

Superior surface - Pericardiophrenic & musculophrenic veins (tributaries of internal thoracic vein)

Inferior surface- R & L inferior phrenic ven (R to IVC, L to supra renal vein)

Front 20

Obj.
Discuss diff types of Congenital diaphragmatic hernias

Back 20

*Failure of pleuroperitoneal membranes to close, usually L sided, bilateral usually fatal
- Note intestines (spleen, stomach, intestines) projecting up into the abdominal cavity
- Lung on respective side can not develop or inflate due to limited space resulting in pulmonary hypoplasia (resp distress & cyanosis)

Front 21

Obj.
Morgagnis hernia

Back 21

failure of fusion btwn xiphoid process & costal margins on the R (rare)

Front 22

Obj.
Hiatal hernia

Back 22

- Lax diaphragmatic fibers at the esophageal hiatus can cause the fundus of the stomach to herniate into the thoracic cavity within the region of posterior mediastinum.
*associated w/ GERD

- This will typically cause an increase in acid reflux symptoms and may require surgery.

Front 23

Obj.
Bochdalek hernia

Back 23

-Left sided
-through opening in L side where pleuroperitoneal membrane fails to close pericardiperitoneal canal
*Most common

Front 24

Nerves of the posterior abdominal wall

Back 24

Ventral ramus of spinal nerve T12 = Subcostal nerve (inferior to rib 12)

Front 25

Abdominal aorta

Back 25

Anterior to vertebral bodies T12-L4
Posterior branches:
-Lumbar arteries (4 on each side) supply posterior abdominal wall (all muscles except diaphram, bones, & spinal cord)
-Inferior phrenic, supply diaphram
-median sacral
*Bifurcates at the level of L4 into R & L common iliac arteries

Front 26

Obj.
Describe the vascular system in the abdomen and the major branches (or tributaries) supplying the digestive, urinary, and reproductive systems

Back 26

Visceral arteries off abdominal aorta
Unpaired:
-Celiac (L1), foregut
-Superior mesenteric (L1), midgut
-Inferior mesenteric (L3), hingut
Paired:
-Middle suprarenal, adrenal glands
-Renal, kidneys
-Testicular or ovarian, testes or ovaries

Front 27

How do the 5 lumbar veins drain the posterior abdominal wall?

Back 27

Ascending lumbar veins receive 1st and 2nd lumbar veins; 3rd and 4th drain directly into IVC, 5th lumbar vein drains into IVC via iliolumbar vein.

Front 28

Describe the venous drainage of post. abdominal wall

Back 28

-R and L iliac veins join to form the IVC (drain pelvis & lower limbs)
-Tributaries of the IVC include the following:
Right testicular/ovarian vein
Renal veins
Right suprarenal vein
inferior phrenic veins
hepatic veins

Front 29

What does the left renal vein drain?

Back 29

drains left testicular/ovarian vein & left suprarenal vein

Front 30

** How does the ascending lumbar vein provides a collateral channel btwn upper & lower body if the IVC is blocked?

Back 30

The ascending lumbar veins connect the iliac, iliolumbar, & lumbar veins w/ the azygos & hemiazygos veins

Front 31

Deep vein thrombosis may occur when a clot enters the __________ and goes into the pulmonary arteries where it becomes an obstruction.

How may this be treated?

Back 31

right side of heart


Prophylactics or and inferior vena cava filter

Front 32

Obj.
Describe the lymphatics on the posterior abdominal wall and the cysterna chyli.

Back 32

-Para-aortic nodes: drain body wall, kidneys, adrenal glands, & testes/ovaries, uterus, uterine tubes --> forms R & L lumbar trunks
-Pre-aortic nodes (celiac, superior & inferior mesenteric): drain GI & acessory organs ---> form intestinal trunk

*all trunks converge to form saccular dilatation = Cisterna chyli (R of abdominal aorta, ant to L1 & 2)

Front 33

Obj.
Describe the formation of the lumbar plexus and identify its branches

Back 33

-Formed by the anterior rami of nerves L1-L3 & most of L4, some contribution from T12
-Branches:
*Iliohypogastric & ilioinguinal (L1)
genitofemoral (L1-2)
lateral cutaneous of thigh (L2-3)
Obturator (L2-4)
*Femoral (L2-L4)
lumbosacral trunk (L4-5)

Front 34

Describe the Crura ligaments

Back 34

*attach diaphragm to bodies & intervertebral discs of lumbar vertebrae

Right crus: L1-L3 & 4 discs
Left crus: L1 & L2 & 4 discs

*pierced by greater & lesser thoracic splanchnic nerves

Front 35

Describe Arcuate ligaments

Back 35

Median arcuate ligament: unites R & L crura (ant to aorta)

Medial arcuate ligament: extends from body of L1 or 2 across psoas to transverse process of L1 (thickening of ant. layer of psoas fascia)

Lateral arcuate ligament: extends from transverse process of L1 to lower margin of rib 12 (thickening of ant layer of thoracolumbar fascia, over quadratus lumborum)

Front 36

What 4 things does the diaphragm develop from?

Back 36

septum transversum
pleuroperitoneal membranes
esophageal mesentary
body wall mesoderm

Front 37

Obj.
Describe the abdominal portion of the Sympathetic trunk

Back 37

Sympathetic trunk & paravertebral ganglia: connected to spinal nerves via communicating rami, conduit for pre & post ganglionic sympathetic fibers, & visceral afferent, ganglia contain postganglionic fibers going to skin & skeletal muscles

Thoracic & Lumbar splanchnic nerves: carry preganglionic sympathetic fibers & visceral afferent fibers

Front 38

Describe the parasympathetic supply to abdomen

Back 38

Pelvic splanchnic from ant rami of S2-4
Vagus C10
* carry preganglionic parasympathetic fibers & visceral afferents

Front 39

What are the 3 pre-vertebral plexuses?


Which 2 contain sympatheyic postganglionic neurons?

Back 39

1. ccliac (solar)- recieves thoracic splanchnic & vagus nerves

2. abdominal aortic (aortic/intermesenteric)- recieves lumbar splanchnic & vagus nerves

3. superior hypogastric- recieves pelvic splanchnic via inferior hypogastric plexus

celiac & abdominal aortic plexus

Front 40

What are the 3 prevertebral ganglia?

Back 40

celiac, superior mesenteric, & inferior mesenteric

* collections of postganglionic sympathetic neuronal cell bodies

Front 41

What do visceral motor efferents and visceral sensory afferents innervate?

Back 41

GVE- smooth muscles of viscera & vessels & glands

GVA- pain sensations from viscera

Front 42

Differentiate btwn the sympathetic & parasympathetic visceral motor efferents

Back 42

sympathetic (T5-L2)
-skin (vessels, sweat glands, & hair), vessels of skeletal muscles (spinal nerves)
-viscera, glands, vessels (splanchnic nerves)

parasympathetic (C10, S2-S4)
-most of Gi & associated glands, kidneys, ureters (vagus)
-descending colon & pelvic viscera (pelvic splanchnic)
*fibers synapse on intrinsic parasympathetic ganglia on or w/i viscera