Lecture 1: Posterior abdominal wall Flashcards
Describe the origin, insertion, action and innervation of the iliacus:
Origin: Iliac fossa
Insertion: Lesser trochanter of femur (joins psoas to form common tendon)
Action: Hip flexion
Innervation: Femoral n. (L2-4)
Describe the origin, insertion, action and innervation of Psoas Major:
Origin: T12,L1-5 (Vertebral bodies and IV discs)
Insertion: Lesser trochanter of femur, (Joins iliacus to form common tendon)
Action: Raise body from supine position (both) / Bend trunk laterally (one) / Flex hip jt.
Innervation: L1-3 (4) (anterior rami)
Describe the origin, insertion, action and innervation of quadratus lumborum:
Origin: Iliac crest
Insertion: 12th rib and L1-4 transverse processess
Action: Both = Forced expiration and 12th rib support, One = Bend trunk to same side
Innervation: T12, L1-4 (ANTERIOR Rami)
What are the muscles of the posterior abdominal wall:
Psoas, Quadratus, Transversus, Iliacus, Diaphragm
Whats the arterial and venous supply of the posterior abdominal wall?
x5 Lumbar arteries
x5 Lumbar veins
Describe the urinary system:
Kidney
Ureter
Bladder
Urethra
Where are all the urinary organs located?
All = Retroperitoneal/infraperitoneal
What is the function of the urinary system:
Removal of waste
Electrolyte balance
pH balance
Blood pressure / volume regulation
Describe the surface anatomy location of the kidneys:
- Post. abdomen
- RK slightly lower than left b/c liver ~Rib12
- Lk sits behind and below Rib 11+12
- Ureters exit kidney @L1 transpyloric plane
Describe the hilums of the kidney:
Renal vein + Renal arteries (also lymphatics and ANS) (Veins anterior to art.)
- Ureters+renal pelvis = posterior to renal vessels
(Note can be divided into upper and lower poles)
What happens to renal arteries when they enter the kidney?
- Arteries branch into anterior and posterior branches before entering the kidney
Describe a key difference in R and L renal veins:
Left renal vein is much longer because the right shifted. The left renal vein also travels between aorta and SMA which can lead to compression and nutcracker syndrome.
Write some notes on the venous supply of the renal veins:
Renal veins -> Into IVC Laterally @L1/2
Left renal vein = x3 longer than right, ant. to aorta, under SMA and post. to splenic v./ body of pancreas.
Right renal vein = Runs post. to secondary duodenum
What is the nerve supply of the kidneys:
Renal plexus:
- Symp; Complicated (T11-12)
- Parasymp; Vagus n.
Referred pain described as flank pain
What is the lymphatics of the kidneys:
Para-aortic nodes (@L1/2)
What are the ureters and what do they do?
Ureter = Smooth muscle muscle tube
Propells urine from kidney via smooth muscle contractions (Filtration pressure from glomeruli)
Why is it important to know the anatomy of the ureter?
V imp. for surgery as they cross many important structures and are around 25cm long
Describe the journey of the ureter:
- Exits kidney @ L1
- Extends vertically down from hilum on surface of Psoas muscle (Roughly inline with transverse process of lumbar spine)
- Crosses bifurcation of common iliac artery (Ant. SI joint)
- Passes on ilium towards ischial spine
- Enters bladder on post. surface at the trigone
Describe the blood supply of the ureter:
Sup 1/3 = Renal art
Mid 1/3 = Gonadal art. and Iliac Art.
Inf 1/3 = Sup. vesical art.
Describe the venous supply of the ureter:
Sup 1/3 = Renal vein
Mid 1/3 = Gonadal vein. and Iliac vein.
Inf 1/3 = Sup. vesical vein.
Describe the nervous supply of the ureter:
Renal plexus (Sup)
Hypogastric plexuses (Inf 1/3)
Pain referred LOIN to GROIN
What are the lymphatics of the ureter?
Para-aortic @ L1/2 to iliac nodes
What are the three constrictions of the ureters?
- Pelvi-ureteric junction
- Ureters crossing pelvic brim
- As they enter the wall of bladder - vesico-ureteric junction
Importance: Most common sites of renal calculus obstruction
Overview the bladder:
- Transition epithelium and rugae
- Muscular SM coat = Detrusor muscle
- Neck of bladder has internal urethral sphincter (SM)
- Apex post. to pubic symphysis
- Bladder fills and rises to suprapubic region
- Partial covering of peritoneum
Ureters enter at the trigone, whats the importance of this and what is it?
- Trigone: Triangular smooth area at base of bladder, mucous membrane, no rugae
- Ureters enter and urethra exits at the points
- B/w ureteric openings is known as the inter-ureteric crest
- The ureteric entrance are oblique (acts as pressure valve to prevent backflow)
What is the art., venous, nervous supply of the bladder:
Arterial: Sup (x2) and inf. vesical arteries on both sides (off internal iliac)
Venous: Vesical plexus (drains to internal iliac vein)
Nervous: ANS inferior hypogastric plexus
Symp: Sacral splenich nn.
Parasymp: Pelvic splanchnic nn.
Pain = Referred to suprapubic region (L1/2 dermatome)
Describe the path of the female urethra:
4cm, leaves bladder and passes through deep and superficial perineal pouches.
Describe the 4 distinct regions of the male urethra:
Pre-prostatic: (Assc with Int. urethral sphincter)
Prostatic: Widest, Many ducts dump
Membranous: Thinnest, Through deep perineal pouch (External urethral sphincter)
Spongy/penile: Through bulb of penis/corpus spongiosum
Describe the lymphatics of the urinary tract:
Ureter: Para-aortic @L1/2, lumbar, common iliac, ext. iliac, int. iliac (as they descend towards bladder)
Bladder: Internal iliac nodes
Urethra: Internal iliac nodes
What do the iliohypogastric and olioinguinal nerves have in common?
Both L1 (Motor and Sensory)
Describe the sensory and motor function of the iliohypogastric nerve:
Sensory: Lateral gluteal and pubic skin
Motor: Transversus abdominus
Describe the sensory and motor function of the ilioinguinal nerve:
Sensory: Skin of medial thigh and root of penis/scrotum or mons pubis/labia majora
Describe the course of the iliohypogastric and ilioingunial nerves:
- Emerge lateral border of Psoas
- Run obliquely over Quad Lumborum (IL1iohypo sup. to IL1ioinguinal)
- Pierce transversus abdominus
Note: Ilioinguinal will pierce internal oblique to enter inguinal canal and accompany spermatic cord through inguinal ring
Where does the gen12ofemoral nerve originate and what are its two main branches?
L1 and L2 (Motor and Sensory)
Two branches:
- Genital
- Femoral
What are the sensory and motor functions of the genitofemoral nerve?
Sensory:
- Scrotum/Mons pubis
- Skin of upper ant. thigh
Motor
- Cremasteric muscle
Describe the course of the genitofemoral nerve:
- Emerges through and runs on top of Psoas
- Genital branch will pass through inguinal canal / spermatic cord to innervate cremaster muscle and give sensory to genital skin
- Femoral branch will pass under inguinal ligament to thigh
What is the origin and function of the lateral femoral cutaneous nerve?
Origin: L2 and L3
Sensory only: Skin on Anterior and lateral thigh (Above the knee)
Describe the course of the lateral femoral cutaneous nerve:
- Emerges from lateral border of Psoas
- Descends obliquely across surface of Iliacus
- Passes under inguinal lig. (At lateral extremity near attatchment to ASIS)
What is a clinical condition associated with the lateral femoral cutaneous nerve?.
Bernhardt-Roth Syndrome (Meralgia parasthetica)
- Numbness of outer thigh due to compression of the nerve as it passes under the inguinal ligament
i.e seat belts, exercise, tight clothing
What is the origin and function of the femoral nerve?
Origin: L2-4 (Its the largest)
Sensory: Skin of anterior thigh and medial leg.
Motor: Pectineus, Iliacus and Anterior compartment of thigh
Describe the course of the femoral nerve:
- Emerges from lower lateral border of Psoas
- Runs between iliacus and Psoas
- Passes under inguinal ligament to thigh
Describe the origins and functions of the obturator nerve:
Origin: L2-4
Sensory: Skin on medial thigh
Motor: Obturator externus and Medial compartment of thigh
What is the course of the obturator nerve?
- Emerges from lower medial border of Psoas
- Passes behind the common iliac arteries, then lateral to internal iliac and ureters
- Runs along walls of pelvic cavity to exit via the Obturator foramen (Specifically through the obturator internus and externus)
