Posterior Abdominal Wall Flashcards
Retroperitoneal organs lie behind the _______ _______.
posterior peritoneum
What are the borders of the Lumbar triangle (of Petit)? What muscles lie within this triangle? What is the clinical significance of this area?
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.
Why does the right kidney sit lower than the left one?
Cuz the liver is big.
What muscle lies immediately posterior to the kidneys? Are the kidneys protected by the ribs posteriorly?
The quadratus lumborum lies posterior to the kidneys. The majority of the kidneys are not protected by ribs and they are vulnerable to trauma.
What does the quadratus lumborum do to the 12th rib when the diaphragm contracts?
It prevents superior displacement of the 12th rib during inhalation.
Name the six major muscles found in the posterior abdominal wall. Are these covered by a fascia?
- Diaphragm
- Transversus abdominis
- Quadratus lumborum
- Psoas major
- Psoas minor
- Iliacus
Yeah they are covered by a fascia.
TB in the lumbar spine can spread from the vertebrae into the _____ _____. This is known as ______’s disease
can spread into the psoas fascia - Pott’s disease
Name the clinical exam finding that can be indicative of a psoas abscess or appendicitis. Describe this test.
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.
Where is pain from a ruptured spleen referred to? Why?
Left shoulder - phrenic nerve C3, 4, 5 shares roots with axillary and supraclavicular.
Does the aorta go through the diaphragm?
No, it goes behind it.
What is a diaphragmatic hernia?
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.
What is eventration of the diaphragm?
Elevation of diaphragm due to
congenital malformation or phrenic nerve interruption from birth or operative trauma.
Arteries in the posterior abdominal wall can be classified as _______ or _______.
paired or unpaired
Are abdominal aortic anuerysms really bad?
Yeah
What two veins drain into the left renal vein? What is the clinical significance of this?
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.
The nerves of the posterior abdominal wall are branches of the ______ plexus.
lumbar plexus
Is the lumbar plexus made up of dorsal, or ventral primary rami?
ventral!
Splanchnic nerves (greater, lesser, least, lumbar) synapse on _______ ganglia; post ganglionic fibers travel on _______ to reach targets.
they synapse on pre-aortic ganglia; post-ganglionic fibers travel on arteries to reach targets
Along what nerve fibers do visceral afferents from the testis and ovaries travel? What is the clinical significance of this?
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.
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?
Felt in the pudendal area from the pudendal nerve.
What are the two main groups of lymph nodes in the abdomen? What does each drain?
Pre-aortic nodes grain the GI system, lumbar/lateral aortic nodes drain everything else in the posterior abdominal wall.
Where are pre-aortic nodes located? What section of the GI tract does each group drain?
They are located near the origin of the main arteries: celiac trunk (drains the foregut), SMA (drains the midgut), IMA (drains the hindgut)
What are the two main groups of lymph nodes in the abdomen? What does each drain?
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.
Where does the lymph from both the pre-aortic and lateral aortic nodes go?
Cisterna chyli –> thoracic duct
Are the kidneys intraperitoneal, primarily retroperitoneal, or secondarily retroperitoneal?
Primarily retroperitoneal
What are the spaces that surround the kidneys called?
The perirenal space is inside the fascia, the pararenal space is outside the fascia.
The pararenal space is divided into a ________ pararenal space and a _______ pararenal space.
anterior and posterior pararenal space
What is Grey-Turner’s sign? What is Cullen’s sign?
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.
What is the lowest space in the abdominal cavity when lying down?
The hepatorenal recess (pouch of Morrison)
What arteries supply the adrenal glands? What do they branch off of?
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.
What is nutcracker syndrome?
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.
What is a phaeochromocytoma?
a tumor of the adrenal medulla (chromaffin cells)
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 ________ ________.
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.
Describe the arterial system that supplies the kidneys.
renal artery –> segmental arteries –> intersegmental arteries –> arcuate arteries –> capillaries
How does urine get from the kidneys into the bladder? What nerves are involved?
Peristalsis. Upper part is from vagus, the part in the pelvic region is from pelvic splanchnic nerves.
Where can the ureter be constricted? What is the clinical significance of this?
- Where the renal pelvis narrows and becomes the ureter.
- Where the ureter crosses the pelvic brim (where the common iliac becomes the internal and external iliac arteries).
- Where the ureter enters the bladder.
Stones get stuck in these spots
Where is pain from a kidney stone in the ureter referred to? Why?
Lower back and inguinal region because visceral afferents are carried on the least splanchnic (T12) and lumbar splanchnic (L1) nerves.
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.
accesory renal artery
Can an accessory renal artery obstruct the ureter?
Yeah but its rare
What is hydronephrosis? What often causes it?
Urine build-up in the kidney, happens when the ureter is blocked. Renal stones can cause it.
What are the clinical features of kidney stones (4)?
- Pain in the lower back, flank with radiation to the groin.
- Hematuria
- Nausa/vomiting
- Dysuria and urgency
How can kidney stones be treated?
shock wave lithotripsy, retrograde ureteroscopy
Where does the femoral nerve lie in relation to the psoas major? What about the obturator nerve?
Femoral nerve is lateral to the psoas major, obturator nerve is medial to it.
Are both adrenal glands similarly shaped? Which one is harder to remove?
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.
