Posterior Abdominal Wall

Question 1

Retroperitoneal organs lie behind the _______ _______.

Answer 1

posterior peritoneum

Question 2

What are the borders of the Lumbar triangle (of Petit)? What muscles lie within this triangle? What is the clinical significance of this area?

Answer 2

The posterior border is the latissimus dosi/thoracolumbar fascia, the anterior border is the external oblique, and the lower border is the iliac crest. The internal oblique and transversus abdominis cover the triangle, and it is a weak point for lumbar hernias.

Question 3

Why does the right kidney sit lower than the left one?

Answer 3

Cuz the liver is big.

Question 4

What muscle lies immediately posterior to the kidneys? Are the kidneys protected by the ribs posteriorly?

Answer 4

The quadratus lumborum lies posterior to the kidneys. The majority of the kidneys are not protected by ribs and they are vulnerable to trauma.

Question 5

What does the quadratus lumborum do to the 12th rib when the diaphragm contracts?

Answer 5

It prevents superior displacement of the 12th rib during inhalation.

Question 6

Name the six major muscles found in the posterior abdominal wall. Are these covered by a fascia?

Answer 6

1. Diaphragm
2. Transversus abdominis
3. Quadratus lumborum
4. Psoas major
5. Psoas minor
6. Iliacus

Yeah they are covered by a fascia.

Question 7

TB in the lumbar spine can spread from the vertebrae into the _____ _____. This is known as ______’s disease

Answer 7

can spread into the psoas fascia - Pott’s disease

Question 8

Name the clinical exam finding that can be indicative of a psoas abscess or appendicitis. Describe this test.

Answer 8

Psoas sign - patient lies on their side and the examiner extends the upward facing leg at the hip. Pain could indicate appendicitis or a psoas abscess.

Question 9

Where is pain from a ruptured spleen referred to? Why?

Answer 9

Left shoulder - phrenic nerve C3, 4, 5 shares roots with axillary and supraclavicular.

Question 10

Does the aorta go through the diaphragm?

Answer 10

No, it goes behind it.

Question 11

What is a diaphragmatic hernia?

Answer 11

Herniation of the intestines through the diaphragm during development, usually on the left side. It causes compression of the developing lung –> pulmonary hypoplasia and hypertension.

Question 12

What is eventration of the diaphragm?

Answer 12

Elevation of diaphragm due to

congenital malformation or phrenic nerve interruption from birth or operative trauma.

Question 13

Arteries in the posterior abdominal wall can be classified as _______ or _______.

Answer 13

paired or unpaired

Question 14

Are abdominal aortic anuerysms really bad?

Answer 14

Yeah

Question 15

What two veins drain into the left renal vein? What is the clinical significance of this?

Answer 15

The left gonadal and left suprarenal veins drain into the left renal vein. The left renal vein can be compressed by the superior mesenteric artery (SMA syndrome) –> edema of the gonads.

Question 16

The nerves of the posterior abdominal wall are branches of the ______ plexus.

Answer 16

lumbar plexus

Question 17

Is the lumbar plexus made up of dorsal, or ventral primary rami?

Answer 17

ventral!

Question 18

Splanchnic nerves (greater, lesser, least, lumbar) synapse on _______ ganglia; post ganglionic fibers travel on _______ to reach targets.

Answer 18

they synapse on pre-aortic ganglia; post-ganglionic fibers travel on arteries to reach targets

Question 19

Along what nerve fibers do visceral afferents from the testis and ovaries travel? What is the clinical significance of this?

Answer 19

Visceral afferents from the testis and ovaries travel back along the least and lesser splanchnic nerves (T11, T12). Pain from the testis/ovaries is referred to the lower abdomen.

Question 20

While pain from the gonads is referred to the lower abdomen via T11, T12 lesser and least splanchnic nerves, where is pain from the skin of the scrotum felt and via which nerve?

Answer 20

Felt in the pudendal area from the pudendal nerve.

Question 21

What are the two main groups of lymph nodes in the abdomen? What does each drain?

Answer 21

Pre-aortic nodes grain the GI system, lumbar/lateral aortic nodes drain everything else in the posterior abdominal wall.

Question 22

Where are pre-aortic nodes located? What section of the GI tract does each group drain?

Answer 22

They are located near the origin of the main arteries: celiac trunk (drains the foregut), SMA (drains the midgut), IMA (drains the hindgut)

Question 23

What are the two main groups of lymph nodes in the abdomen? What does each drain?

Answer 23

Pre-aortic nodes grain the GI system, lumbar/lateral aortic nodes drain everything else in the posterior abdominal wall, including the muscles, kidneys, pelvis, and lymph from the superficial inguinal nodes –> deep inguinal –> nodes along the external iliac –> lateral aortic nodes.

Question 24

Where does the lymph from both the pre-aortic and lateral aortic nodes go?

Answer 24

Cisterna chyli –> thoracic duct

Question 25

Are the kidneys intraperitoneal, primarily retroperitoneal, or secondarily retroperitoneal?

Answer 25

Primarily retroperitoneal

Question 26

What are the spaces that surround the kidneys called?

Answer 26

The perirenal space is inside the fascia, the pararenal space is outside the fascia.

Question 27

The pararenal space is divided into a ________ pararenal space and a _______ pararenal space.

Answer 27

anterior and posterior pararenal space

Question 28

What is Grey-Turner's sign? What is Cullen's sign?

Answer 28

Grey-Turner's is when blood-stained pancreatic exudate from the anterior pararenal space invades through abdominal wall tissue. Cullen's sign is when liberated pancreatic enzymes track to the anterior abdominal wall from the gastrohepatic ligament and across the falciform ligament. It is indicative of acute pancreatitis.

Question 29

What is the lowest space in the abdominal cavity when lying down?

Answer 29

The hepatorenal recess (pouch of Morrison)

Question 30

What arteries supply the adrenal glands? What do they branch off of?

Answer 30

Superior suprarenal arteries are branches of the inferior phrenic arteries, middle suprarenal arteries come off the aorta, inferior suprarenal arteries are branches off the renal artery.

Question 31

What is nutcracker syndrome?

Answer 31

When the SMA compresses the left renal vein. Can cause pain in the left flank, gonad (left gonadal vein drains into the left renal vein), and hematuria.

Question 32

What is a phaeochromocytoma?

Answer 32

a tumor of the adrenal medulla (chromaffin cells)

Question 33

The adrenal medulla is innervated by __________ sympathetic nerve fibers, and its cells are derived from ______ _____ cells. The cortex, however, is innervated by ___________ fibers from the ________ ________.

Answer 33

medulla is innervated by PREganglionic sympathetic fibers and cells are derived from neural crest cells; cortex is innervated by postganglionic fibers from the celiac ganglion.

Question 34

Describe the arterial system that supplies the kidneys.

Answer 34

renal artery --> segmental arteries --> intersegmental arteries --> arcuate arteries --> capillaries

Question 35

How does urine get from the kidneys into the bladder? What nerves are involved?

Answer 35

Peristalsis. Upper part is from vagus, the part in the pelvic region is from pelvic splanchnic nerves.

Question 36

Where can the ureter be constricted? What is the clinical significance of this?

Answer 36

1. Where the renal pelvis narrows and becomes the ureter. 2. Where the ureter crosses the pelvic brim (where the common iliac becomes the internal and external iliac arteries). 3. Where the ureter enters the bladder. Stones get stuck in these spots

Question 37

Where is pain from a kidney stone in the ureter referred to? Why?

Answer 37

Lower back and inguinal region because visceral afferents are carried on the least splanchnic (T12) and lumbar splanchnic (L1) nerves.

Question 38

The kidneys begin to develop in the pelvis and “ascend” to their adult position in the upper lumbar region. As they ascend, they acquire renal arteries and normally shed lower ones. However, some of these early-developing arteries may persist as an ________ ________ artery.

Answer 38

accesory renal artery

Question 39

Can an accessory renal artery obstruct the ureter?

Answer 39

Yeah but its rare

Question 40

What is hydronephrosis? What often causes it?

Answer 40

Urine build-up in the kidney, happens when the ureter is blocked. Renal stones can cause it.

Question 41

What are the clinical features of kidney stones (4)?

Answer 41

1. Pain in the lower back, flank with radiation to the groin. 2. Hematuria 3. Nausa/vomiting 4. Dysuria and urgency

Question 42

How can kidney stones be treated?

Answer 42

shock wave lithotripsy, retrograde ureteroscopy

Question 43

Where does the femoral nerve lie in relation to the psoas major? What about the obturator nerve?

Answer 43

Femoral nerve is lateral to the psoas major, obturator nerve is medial to it.

Question 44

Are both adrenal glands similarly shaped? Which one is harder to remove?

Answer 44

No, the right one is pyramidally shaped and the left one is crescent-shaped. The right one is harder to remove because it lies behind the IVC.