Posterior Abdominal Wall

Question 1

Give a list of retroperitoneal structures that are primarily retroperitoneal. What does it mean to be primarily retroperitoneal?

Answer 1

Primarily Retroperitoneal means that developmentally they started outside of the peritoneum and they finished that way.
Urinary System
Adrenal Glands
Sympathetic Trunk + Branches to Ganglia
Thoracic Duct + Cisterna Chyli
Posterior Abdominal Wall
Aorta & IVC
Rectum

Question 2

What is the relationship b/w the rectum & the peritoneum?

Answer 2

The rectum is both retroperitoneal & subperitoneal.
The superior portion is retro & has peritoneum on its anterior surface. The middle & inferior portions are below the floor of the peritoneum & are not covered at all in it.

Question 3

Double folds of peritoneum = ?

What runs thru this structure?

Answer 3

Ligament!!

blood vessels/vasculature stuff runs thru it

Question 4

What 2 ligaments make up the lesser omentum?

Answer 4

hepatogastric ligament

hepatoduodenal ligament

Question 5

What is the relationship b/w the lesser omentum & the lesser sac?

Answer 5

The lesser omentum is on the anterior surface of the lesser sac.

Question 6

With the gastrosplenic ligament…the peritoneum comes from ___ & reflects ____.

Answer 6

Comes from the stomach & reflects onto the spleen.

Question 7

Which kidney is typically lower? Why?

Answer 7

The right kidney b/c the liver is pushing down on it.

Question 8

Which ribs typically cover the right & left kidney?

Answer 8

Right Kidney: typically covered by only 12th rib

Left Kidney: typically covered by 11th & 12th rib

Question 9

What is the renal fascia?

Answer 9

It surrounds the kidneys…it is essentially a continuation of the kidney’s vasculature or adventitia…

Question 10

What is the order of protective layers starting from the peritoneum & ending up in the kidney?

Answer 10

Peritoneum
Pararenal fat
Renal Fascia
Perirenal fat
Kidney Capsule!

Question 11

Describe the blood supply to the kidneys.

Answer 11

Renal arteries come off of the aorta near the SMA & divide into anterior & posterior segmental branches (to go to the 2 lobes of the kidney)…
There will also be polar branches from the kidney’s development & ascent.

Question 12

What are 3 sources of blood supply for the ureter?

Answer 12

renal
gonadal
vesicular

Question 13

Describe the functional sphincter of the ureter.

Answer 13

It enters the bladder at a diagonal so that when the bladder fills it pushes up against it & doesn’t back flow.

Question 14

What are 3 sites of potential narrowing of the ureter where kidney stones can get stuck?

Answer 14

transition from pelvis to ureter
pelvic brim
entry into bladder

Question 15

How many layers of muscle does the ureter have?

Answer 15

3–very muscular, can propel urine!!

Question 16

Describing in terms of vertebrae–>what are 2 locations where kidney stones might get stuck?

Answer 16

T11-T12

L1-L2

Question 17

the ureter enters the bladder @ the point where…

Answer 17

at the point where the common iliac divides into the internal & external iliacs.

Question 18

Where do the sympathetics to the kidney come from?

Answer 18

thoracic splanchnic nerves (lesser & least)
lumbar splanchnics (usu L1)

Question 19

Where is the aorticorenal ganglion?

Answer 19

a small ganglia on the renal artery

Question 20

Where do the sympathetics to the kidneys synapse?

Answer 20

aorticorenal ganglion

probably the SMA

Question 21

Where do the parasympathetics to the kidneys come from?

Answer 21

pelvic splanchnics

vagus

Question 22

Where do the parasympathetic to the kidneys synapse?

Answer 22

in the renal sinus

Question 23

What bus do the sensory fibers hop on to on their return?

Answer 23

They return via the vagus & the sympathetics

Question 24

What bus do the sensory fibers from the ureter hop on to?

Answer 24

Vagus
Sympathetics
dorsal root ganglions via T12-L2 spinal nerves

Question 25

Describe the blood supply to the suprarenal glands.

Answer 25

Superior Suprarenal: from the inferior phrenic artery Middle Suprarenal: from the aorta directly Inferior Suprarenal: from the renal artery

Question 26

Describe the venous drainage of the suprarenal glands.

Answer 26

The right kidney drains directly into the IVC. | The left kidney can either drain directly into the IVC or into a renal vein.

Question 27

What is the only autonomic pathway with just one neuron?

Answer 27

The preganglionic sympathetic fibers that innervate the secretory cells of the adrenal medulla. These cells sorta act like postganglionic neurons by secreting "NT" of Epi or NE into the bloodstream. This produces slow acting but longer lasting affects in various parts of the body.

Question 28

T/F The sympathetic innervation to the adrenal cortex is only preganglionic.

Answer 28

FALSE. To the adrenal medulla...to the adrenal cortex it is normal.

Question 29

So...describe the innervation of the adrenal cortex & adrenal medulla with respect to the celiac ganglion.

Answer 29

Okay...so a bunch of fibers go to the celiac ganglion & synapse & then go to the adrenal cortex. But a bunch of fibers peel away from the celiac ganglion & go to the adrenal medulla as preganglionics.

Question 30

Stuff coming off of the sympathetic chain posterolaterally is considered...

Answer 30

communicating rami

Question 31

If you see a communicating ramus (only 1) where are you in the body?

Answer 31

You are below the L2 region...b/c the 2 communicating rami only come off of the T1-L2 region. After that, it is just one.

Question 32

``` If you see stuff coming off the sympathetic chain in the anteriomedial direction...what does that mean? What if it is in the: thorax lumbar pelvis ```

Answer 32

Splanchnics!! Thorax: thoracic splanchnics Lumbar: lumbar splanchnics Pelvis: sacral splanchnics

Question 33

90% of the innervation of the pelvic viscera comes from what?

Answer 33

Hypogastric nerves

Question 34

10% of the innervation of the pelvic viscera comes from what?

Answer 34

Sacral Splanchnics

Question 35

Where do the hypogastric nerves come from? Where do they go?

Answer 35

Come from: Superior Hypogastric Plexus | Go to: Inferior Hyopgastric Plexus

Question 36

Where does the vagus stop in the GI tract?

Answer 36

the splenic flexure | then pelvic splanchnics take over...

Question 37

What happens to the R & L Vagus nerves? Tell the full story.

Answer 37

R & L Vagus nerves Go to the Esophageal Plexus 2 trunk: anterior (mainly L vagus) & posterior (mainly R vagus) on the distal end of the esophagus

Question 38

Where does the posterior trunk go?

Answer 38

to the greater curvature & to the jejunum & ileum & descending colon

Question 39

Where does the anterior trunk go?

Answer 39

to the lesser curvature & to the liver & celiac trunk etc.

Question 40

How far do the vagal trunks extend?

Answer 40

only to the splenic flexure... | After that: pelvic splanchnics

Question 41

What forms the thoracic duct?

Answer 41

one intestinal trunk & 2 lumbar trunks

Question 42

Where do they all join together?

Answer 42

@ cisterna chyli, a dilation just inferior to the diaphragm

Question 43

How can you access the cisterna chyli in lab?

Answer 43

by cutting thru the right crus of the diaphragm

Question 44

Do all of the intestinal loops drain into the intestinal trunk?

Answer 44

No. Some of them (esp the sigmoid colon & rectum) drain into the lumbar trunks.

Question 45

What are the quadratus lumborum & psoas major muscle mainly involved in?

Answer 45

MOVEMENT! How fun!

Question 46

What does the quadrates lumborum arise from & attach to? What is its main function?

Answer 46

Arises from: transverse processes from the vertebrae & ribs Attaches to: superior border of the iliac crest **keeps the pelvis from sagging

Question 47

Which 2 ligaments arch over the psoas major & quadratus lumborum muscles?

Answer 47

the medial & lateral arcuate ligaments

Question 48

What's something identifying about the ilioinguinal nerve?

Answer 48

It enters the inguinal canal.

Question 49

T/F Both the ilioinguinal & iliohypogastric nerves enter the inguinal canal. This makes it hard to distinguish b/w them.

Answer 49

False. | Only the ilioinguinal nerve passes thru the inguinal canal.

Question 50

Where does the lateral femoral cutaneous nerve come off? Where does it go to?

Answer 50

It comes off the anterior superior iliac spine. | It goes to the anterior thigh.

Question 51

Where is the genitofemoral nerve found?

Answer 51

on top of the psoas major muscle...

Question 52

Where is the subcostal nerve found?

Answer 52

@ T12, just below the ribs!

Question 53

Where can the obturator nerve be found?

Answer 53

medial & inside the pelvic cavity...it enters the obturator foramen & pierces the obturator muscle...

Question 54

What vertebrae levels does the femoral nerve correspond to?

Answer 54

L2-L4

Question 55

What vertebrae levels does the obturator nerve correspond to?

Answer 55

L2-L4

Question 56

What 2 main things does the inferior phrenic artery supply?

Answer 56

the undersurface of the diaphragm & the superior suprarenal artery to the adrenal gland

Question 57

What is the tiny branch off of the aorta that goes straight down the middle by L5 b/w the iliacs?

Answer 57

median sacral artery

Question 58

What are the branches off of the abdominal aorta...in order from top to bottom?

Answer 58

``` Inferior Phrenics Celiac Artery Middle Suprarenal SMA Renal Gonadal IMA Lumbar arteries Common iliacs median sacral artery ```

Question 59

What is different about the gonadal vein on the left side?

Answer 59

On the right side...empties into the IVC | On the left side...empties into the renal vein & then into the IVC

Question 60

What are the posterior wall veins that drain into the IVC?

Answer 60

``` Inferior Phrenic Hepatic Renal Right Suprarenal Right Gonadal Common iliacs Lumbar veins (somehow connected w/ the azygos) ```

Question 61

The medial arcuate ligament is found crossing what muscle?

Answer 61

the psoas major muscle

Question 62

The lateral arcuate ligament is found crossing which muscle?

Answer 62

the quadratus lumborum

Question 63

Where do the right & left crura extend? Which is longer?

Answer 63

They extend inferiorly to attach to vertebral bodies. | the right one is longer.

Question 64

Which hiatus do the crura extend into? One of them also creates the fascial lining for what?

Answer 64

Esophageal Hiatus | Ligament of Trietz

Question 65

What are the 3 important structures that create holes in the diaphragm? Where do they do this?

Answer 65

IVC @ T8 Esophagus @ T10 Aorta @ T12

Question 66

What little thing pierces thru the diaphragm?

Answer 66

thoracic splanchnic nerves

Question 67

How does the sympathetic trunk get thru the diaphragm?

Answer 67

It passes behind it.

Question 68

How does the vagal trunk get thru the diaphragm?

Answer 68

It passes thru the esophageal hiatus.

Question 69

What is the lumbocostal trigone? What can it cause?

Answer 69

It is a congenital defect formed by an area where 2 things fused... It can cause a herniation of abdominal contents into the thorax...w/ a hypo plastic lung **most common diaphragmatic hernia **occurs on the left side more often than the right b/c of the presence of the liver

Question 70

The esophagus opening is usu formed almost entirely by fibers from______.

Answer 70

the right crus!!

Question 71

Which 4 embryonic structures form the diaphragm?

Answer 71

septum transversum pleuroperitoneal membranes dorsal mesentery of the esophagus cervical somites

Question 72

What does the dorsal mesentery of the esophagus form?

Answer 72

crura

Question 73

What do the cervical somites form?

Answer 73

body wall

Question 74

What is the hernia from the lumbocostal trigone equivalent to?

Answer 74

Bochdalek hernia b/c of the failure to fuse 2 peritoneal folds...

Question 75

What does the septum transversum form?

Answer 75

the central tendinous region & a little bit of musculature

Question 76

What do the pleuroperitoneal membranes form?

Answer 76

musculature & posterior body wall | **doesn't close off completely @ the area of the trigone

Question 77

T/F Anterior thoracic wall is another potential space for a diaphragmatic hernia.

Answer 77

True. B/c of the different embryological structures that fuse to form the membrane...a bunch of different hernias are possible.

Question 78

Postsynaptic sympathetic fibers off of the celiac ganglion travel on what?

Answer 78

mainly on blood vessels