ABDOMEN V Flashcards
What are the bones of the posterior abdominal wall?
The bodies of the lumbar vertebrae, floating ribs 11 and 12, the ilium of the pelvis, the sacrum and the sacroiliac joint
At what level do the iliac tubercle and iliac crest lie, and what’s the clinical importance?
L4. This is a safe place for a lumbar puncture
What muscle group does the ASIS give attachment to?
The quadriceps
Where does psoas major arise and insert?
Arises from vertebral bodies and the intervertebral discs of T12-L4, and the transverse processes of L1-L5. Inserts at the lesser trochanter of the femur as the iliopsoas tendon
What’s the action of psoas major?
Flex the thigh at the hip joint and flex the trunk
What nerves innervate psoas major?
The anterior rami of spinal nerves L1-L3
What branch supplies the psoas major with blood?
The lumbar branch of the iliolumbar artery
What’s the origin and insertion of iliacus?
Origin- the upper 2/3 of the iliac fossa, the internal lip of the iliac crest, the lateral aspect of the sacrum
Insertion- lesser trochanter of the femur (anterior to the fibres of psoas major)
Action of iliacus?
Flexion of the hip joint and trunk and external rotation of the thigh
Quadratus lumborum origin and insertion
Origin- iliac crest, iliolumbar ligament
Insertion- inferior border of the 12th rib, and the transverse processes of vertebrae L1-L4
Function of quadratus lumborum
Bilateral contraction fixes ribs 12 during inspiration and causes trunk extension.
Unilateral contraction causes ipsilateral flexion of the trunk
Innervation to quadratus lumborum
Subcostal nerve T12, and the anterior rami of spinal nerves L1-L4
Innervation to iliacus
Branches of spinal nerves L2-L4
Origin and insertion of psoas minor
Origin- vertebral bodies of T12 and L1 vertebrae
Insertion- branches of the lumbar plexus (L1-L3)
Functions of psoas minor
Weak trunk flexion and lateral trunk flexion
What are the 3 peripheral attachments of the diaphragm?
The lumbar vertebra and arcuate ligaments
The costal cartilages of ribs 7-10 and directly to ribs 11 and 12
The xiphoid process of the sternum
What are the parts of the diaphragm that arise from the vertebrae?
The right and left crura, which are tendinous in structure
What vertebrae does the right crus arise from?
L1-L3 and their intervertebral discs
What’s the physiological importance of the right crus?
Some of its fibres wrap around the LOS, acting as a component of the sphincter to prevent reflux of gastric contents
What vertebrae does the left crus arise from?
L1-L2 and their intervertebral discs
What do the muscle fibres of the diaphragm combine to form?
A central tendon which ascends to fuse with the inferior surface of the fibrous pericardium
What does the caval hiatus at T8 allow passage of?
The IVC and terminal branches of the right phrenic nerve
What does the oesophageal hiatus allow passage of?
The oesophagus, right and left vagus nerves, and the oesophageal branches of the left gastric artery/vein
What does the aortic hiatus allow passage of?
The aorta, thoracic duct and azygous vein
Where do the hiatuses of the diaphragm lie in relation to eachother?
The caval hiatus is the most anterior, lying slightly to the right. The oesophageal hiatus is more to the left, then the aortic hiatus is just anterior to the spinal column, and central
What is the median arcuate ligament?
An arch-shaped ligament under the diaphragm that connects the right and left crura. The aortic hiatus is deep to the ligament
What can compression of the coeliac artery and coeliac ganglia by the median arcuate ligament lead to?
Median arcuate ligament syndrome (characterised by abdominal pain, weight loss and an epigastric bruit)
What does the iliohypogastric nerve of the lumbar plexus (L1) provide?
Sensory innervation to the posterolateral gluteal skin and the skin over mons pubis. Motor innervation to internal oblique and transversus abdominis
What does the ilioinguinal nerve of the lumbar plexus (L1) provide?
Sensory innervation to skin in the upper medial thigh, the skin over the root of the penis and anterior scrotum or mons pubis and labia majora. Motor innervation to the internal oblique and transversus abdominis
What does the genitofemoral nerve of the lumbar plexus (L1-L2) provide?
Sensory innervation to the skin of the anterior scrotum or mons pubis and labia majora, and skin of the upper anterior thigh. Motor innervation to the cremaster muscle
What does the Lateral femoral cutaneous nerve of the thigh (L2-L3) provide?
Sensory innervation to the skin of the anterior and lateral thigh to the knee
What does the femoral nerve of the lumbar plexus (L2-L4) provide?
Sensory innervation to the skin of the anterior thigh and medial surface of the leg. Motor innervation to iliacus, pectineus and quadriceps
What does the obturator nerve of the lumbar plexus (L2-L4) provide?
Sensory innervation to the skin of the medial thigh. Motor innervation to the obturator externus, pectineus and muscles in the medial compartment of the thigh
Where is the IVC formed?
At the level of L5, where the common iliac veins unite
What’s the yellow cortex of adrenal glands derived from?
Mesoderm
What is synthesised at the cortex of the adrenal glands?
Catecholamines
What is the brown medulla of the adrenal glands derived from?
The neural crest
What is synthesised at the medulla of the adrenal glands
ZG-mineralocorticoids
ZF- glucocorticoids
ZR- androgens
At what level are the hila of the kidneys?
L1
What is the renal angle?
The area between the 12th rib and the lateral border of the erector spinae muscle, where the kidney can be palpated
How’s the descending duodenum related to the right kidney?
It runs anteriorly to it, close to the hilum
What muscle is posterior to the kidneys?
Quadratus lumborum
What muscle is posteromedial to the kidneys?
Psoas major
What’s found within the perirenal space?
Perinephric fat
What are renal columns?
Extensions of the renal cortex between the pyramids
Are pyramids part of the cortex or medulla of the kidney?
The medulla
What do renal papillae open into?
A minor calyx
What do minor calyxces merge to form?
Major calyces
What is the renal sinus?
A cavity continuous with the renal pelvis
What is the renal pelvis?
A funnel-ended, dilated part of the ureter
Describe the contents of the hilum of the kidney from anterior to posterior
The renal vein, the renal artery, the ureter
VAU
What is the hepatorenal pouch of Morrison?
The space that separates the liver from the right kidney. As a potential space, the recess is not filled with fluid under normal conditions
At what level do the renal arteries branch off the aorta?
L1-L2
Which renal artery is longer?
The right renal artery is longer than the left
Briefly describe the branching of the renal arteries
The renal artery gives off 5 segmental arteries, 4 anterior and 1 posterior. These each then give off lobar arteries, which give off interlobar arteriestowards the cortex, which give off arcuate arteries that give off interlobular arteries that ascend into the cortex and give off afferent glomerular arterioles
Describe the left renal vein in comparison to the right renal vein
Enters the IVC superior to the right renal vein. 3x longer than the right renal vein. Preferred side for a live donor nephrectomy
What is the right renal vein posterior to?
The 2nd part of the duodenum and the head of the pancreas
What do the interlobular veins receive?
The efferent glomerular veins
What nodes do the lymphatics of the kidneys drain into?
The left and right lumbar nodes near the origin of the renal arteries
What nerves give vasomotor regulation of bloodflow and renin secretion?
Nerves of the renal plexus, as well as post-ganglionic sympathetic fibres from T10-L2
What are staghorn calculi?
Calculi made from struvite. Recurrent UTI causes increase in ammonia production, increase in pH and decreased phosphate solubility
How does the course of the ureters in the abdomen relate to psoas major, the genitofemoral nerve, the gonadal vessels, and the bifurcation of the common iliac artery?
They pass anteriorly to psoas major and cross the genitofemoral nerve anteriorly. They are obliquely crossed by the gonadal vessels. They then cross the bifurcation of the common iliac arteries to enter the pelvis
How does the course of the ureters in the pelvis relate to the internal iliac artery, the ischial spine, vas deferens/ the uterine artery, and the wall of the bladder?
The ureters run down anteriorly to the internal iliac artery to reach the ischial spine, where they turn anteromedially. Near their termination, they are crossed by vas deferens or the uterine artery. They pass obliquely through the bladder wall for about 3/4 inch, before opening into the bladder cavity
Where is pain referred from renal and ureteric calculi?
From the loin to the groin
What is ureteric colic?
Severe intermittent pain due to contraction of ureteric muscles to overcome an obstruction, usually due to a stone or clot formation
What are the 3 points of constriction of the ureter?
The ureteropelvic junction
The crossing of the common iliac artery
The site of entrance to the bladder
What 4 arteries supply the ureter?
The renal artery, gonadal artery, common iliac artery, and internal iliac artery
Is the bladder intraperitoneal or extraperitoneal?
Extraperitoneal
What is the retropubic space of Retzius?
The space between the pubic symphysis and the bladder in both males and females
Where’s the prostate in relation to the bladder?
Directly posterior
What’s the importance of the median umbilical ligament that runs from the apex of the bladder to the umbilicus?
It’s a remnant of the urachus, a fibrous remnant of allantois. This functioned to drain the foetal urinary bladder
What is the pubovesical ligament in females?
A ligament attached to the pubic symphysis which wraps around the neck of the bladder and the urethra.
What causes stress incontinence after parturition?
Increased intraabdominal pressure causes the neck to be below the pelvic floor
What is the puboprostatic ligament in males?
A ligament attached to the pubic symphysis that wraps around the prostate
Describe the arterial supply to the bladder
The bladder is supplied by the superior vesical artery- a branch of the umbilical artery from the anteiror trunk of the internal iliac. In males, there’s also the inferior vesical artery. Its ‘female equivalent’ is the vaginal artery
Describe the venous drainage of the bladder
The bladder is drained by the vesical venous plexus, which drains into the internal iliac vein
What’s the sympathetic innervation of the bladder for urine retention?
T10-L2 spinal nerves that enter into the sympathetic chain and synapse in the pre-vertebral plexi
What’s the parasympathetic innervation to the bladder for micturition?
Pelvic splanchnic nerves (S2-S4) pass through the inferior hypogastric plexus
Describe the lining of the femal urethra
The proximal 2/3 is lined by transitional epithelium. The distal 1/3 is stratified squamous epithelium
What are the 4 parts to the male urethra?
The pre-prostatic urethra, the prostatic urethra, the membranous urethra and the spongy urethra
What does the ureteropelvic junction usually coincide with?
The transverse processes of L2
What bony landmark does the crossing of the ureter over the common iliac artery coincide with?
The sacroiliac joint
What bony landmark does the ureters’ entrance to the bladder coincide with?
An imaginary line form the AIIS to the bladder
What’s an ectopic kidney and symptoms?
A congenital defect in which a kidney is located in an abnormal position, e.g. the pelvic cavity or inguinal position. It’s mostly asymptomatic, but can give urinary problems, and can lead to hydronephrosis due to blockage
What is nephroptosis (floating kidney, wandering kidney, renal ptosis)?
A condition in which the kidney drops down into the pelvis when the patient stands up. It’s more common in women than men
What does the urachus connect and what happens to it at 32 weeks?
The urachus connects the urinary bladder to the umbilicus. At 32 weeks, urachus obliterates to become the median umbilical ligament. When covered with parietal peritoneum, it’s called the median umbilical fold
What does the neurovascular plane run between?
The internal oblique and transversus abdominis
Where do the gonads develop?
Close to the posterior abdominal wall
