Urinary tract, Posterior Abdominal Wall and Pelvis Flashcards
Where is the right adrenal gland in relation to other organs?
Where is the left adrenal gland in relation to other organs?
Close to the upper pole of the right kidney
Behind the liver and inferior vena cava
Close to the upper pole of the left kidney
Behind the stomach and pancreas
What is the arterial blood supply of the adrenal glands?
For each there are 3 arteries…
Superior adrenal artery - branch of inferior phrenic
Middle adrenal artery - branch of abdominal aorta
Inferior adrenal artery - branch of renal artery
What is the venous supply of the adrenal glands?
Drained by a single vein on each side
Right adrenal vein drains directly into inferior vena cava
Left adrenal vein drains into left renal vein, that joins inferior vena cava
What is the position of the kidneys relative to the peritoneum? The spinal vertebrae?
Located outside the peritoneum so are extra-peritoneal
Also referred to as retro-peritoneal to distinguish that they are behind
Either side of the upper lumbar vertebrae
What layers cover the kidney?
Embedded in perinephric fat
This layer covered by renal fascia
Further layer of paranephric fat on top
What enters/ exits the kidney by the renal hilum? Where is the renal hilum?
Renal vessels, nerves, lymphatics, and ureter
Medial border of the kidney
What are the dimensions of the kidney?
11cm long
7cm wide
3cm thick
What is the arterial supply of the kidney?
Venous?
L/r renal arteries are branches of the abdominal aorta
L/r renal veins both drain directly into inferior vena cava
What are the 3 internal aspects of the kidney?
Cortex - outer - most of the nephron
Medulla - inner part, arranged into pyramids
Calyces - minor, major, (pelvis)
What are the functional units of the kidneys?
Which parts are in the cortex?
Which parts are in the medulla(renal pyramids)?
nephrons - responsible for filtering blood
Cortex - glomeruli, glomerular capsule, proximal and distal tubules and part of the collecting ducts
Renal pyramids - nephron loop (Henle) and rest of collecting ducts
Draw and label a picture of a kidney…
What are the labels? [10]
Renal capsule
Renal cortex
Renal columns
Renal pyramids
Renal papilla
Renal sinus
Minor calyx
Major calyx
Renal pelvis
Ureter
What is the pathway of the urine after being drained into the collecting ducts of the nephrons?
Down the pyramids towards the renal papilla
Enters a minor calyx
Minor calyces merge to form major calyx
Major calyces merge to form the pelvis
The pelvis is continuous with the ureter
Ureters carry urine to bladder
How is urine transported?
Peristalsis in ureter
Where are the ureters located?
Anterior to psoas major on the posterior abdominal wall
Where is the bladder in terms of the peritoneum?
In the pelvis below the peritoneum
Therefore infra-peritoneal
What is the position of the bladder in the pelvis?
Posterior to the pubic synthesis
Anterior to the vagina and rectum
Below the peritoneum (infra-peritoneal)
If empty it may be squashed down
When full, superior aspect may extend above the pubic symphysis
What is micturition?
The act of urinating
What is the detrusor?
Smooth muscle in the wall of the bladder
Contracts to forcibly expel urine
What is the name of the area where the ureters join the posterior aspect of the bladder?
Trigone
Posterior aspect, near the base
Has a smooth internal wall
How do the ureters enter the trigone?
Near the base of the posterior aspect of the bladder
At an angle
Form a rudimentary valve that prevents reflux of urine into ureters when the bladder is full
How much urine can the bladder accommodate in an adult?
Approx 400 - 600 ml urine
Describe the inside wall of the bladder
Corrugated with folds of mucosa called rugae
Allow the bladder to stretch without tearing when it fills
What is the arterial supply of the bladder?
Venous supply?
Vesical arteries that branch from internal iliac artery
Vesical veins drain into internal iliac vein
Which two sphincters control release of urine from the bladder?
Internal - inside - smooth muscle - involuntary
External - outside so can override - skeletal muscle - voluntary
What is the location of the …
- internal sphincter
- external sphincter
… in the bladder?
- internal - base of the bladder where it opens into the urethra, beginning of membranous urethra
- external - males - just inferior to the prostate
- external - females - deep perineal pouch
What requires and what supplies the somatic innervation of the bladder?
External urethral sphincter
Branches of the pudendal nerve (S2-S4)
Allows conscious control
What requires and what supplies the sympathetic innervation of the bladder?
Relaxation of the detrusor and contraction of the internal urethral sphincter
Branches of hypogastric nerve (T12-L2 sympathetic chain)
Allows storage of urine
What requires and what supplies the parasympathetic innervation of the bladder?
Contraction of the detrusor and relaxation of the internal urethral sphincter
Pelvic splanchnic nerves (S2-S4)
Allows initiation of micturition
Where does the urethra carry urine to/from?
From the internal urethral orifice
To the external urethral orifice (vestibule in females, tip of penis in males)
What is the male urethra sub-divided into?
pre-prostatic
prostatic
membranous
penile
Which area is the posterior abdominal wall?
Region behind the abdominal cavity
Extends from the attachments of the diaphragm superiorly
To the pelvic brim inferiorly
What does the posterior abdominal wall consist of? [3]
What is the posterior abdominal wall associated with? [5]
Lumbar spine
Psoas muscles (major and minor)
Quadratus lumborum muscles
Aorta (+autonomic plexuses and lymph nodes)
Inferior vena cava
Sympathetic trunks
Gonadal vessels descend over ureters to supply gonads
Ureters descend over psoas muscle
Which spinal nerves form the lumbar plexus?
What does it innervate?
What are the 6 most notable branches?
L1-L4 (and contribution from T12)
Skin and muscles of the abdominal wall and thigh
iliohypogastric and ilioinguinal nerves
Genitofemoral nerve
Lateral femoral cutaneous nerve
Femoral nerve
Obturator nerve
Where do the iliohypogastric and ilioinguinal nerves originate from?
Where are they found?
What do they innervate?
Lumbar plexus (L1-L4)
Posterior abdominal wall
Anterior abdominal wall muscles and skin of the external genitalia
Where does the genitofemoral nerve originate from?
Where is it found?
What does it innervate?
Lumbar plexus L1-L4
Posterior abdominal wall
Skin of external genitalia
Where does the lateral femoral cutaneous nerve originate from?
Where is it found?
What does it innervate?
Lumbar plexus L1-L4
Posterior abdominal wall
Supplies skin over the lateral thigh
- aka lateral cutaneous nerve of the thigh
Where does the femoral nerve originate from?
Where is it found?
What does it innervate?
Lumbar plexus L1-L4
Posterior abdominal wall
Muscles and skin of the anterior thigh
Large nerve, often targeted by nerve blocks for pain relief in lower limb
Where does the obturator nerve originate from?
Where is it found?
What does it innervate?
Lumbar plexus L1-L4
Posterior abdominal wall
Muscles and skin of medial thigh
What is the aorta’s path through the abdomen?
Thoracic aorta enters diaphragm at T12 vertebra
Becomes abdominal aorta, which sits just left of midline
Terminates by bifurcating into left and right common iliac arteries at approx level of L4
What unpaired arteries does the abdominal aorta give rise to?
What paired branches does the abdominal aorta give rise to?
coeliac trunk, superior mesenteric artery, inferior mesenteric artery
Renal, adrenal, gonadal and lumbar arteries
What do the lumbar arteries supply?
The posterior abdominal wall
What is the path of the inferior vena cava in the abdomen?
Union of left and right common iliac veins form inferior vena cava at approx L5
Sits just right of midline on posterior abdominal wall
Passes through diaphragm at T8
Which veins drain into the inferior vena cava in the abdomen?
Veins corresponding to paired arteries from aorta
Though left gonadal drains into left renal typically
Also receives hepatic veins before passing through diaphragm
At what vertebral level do the aorta and vena cava pass through the diaphragm? Bifurcate/form?
Aorta - diaphragm - T12
bifurcates - L4
Inferior vena cava - diaphragm - T8
forms - L5
What are the functions of the bony pelvis?
Supporting the spine, torso and upper body
Locomotion
Housing and protecting the pelvic viscera
What are the 3 bones of the pelvis?
What are the 3 bones fused together to form one of these bones?
Sacrum
Left/right hip bones
Hip bone - ilium, ischium, pubis
What are the 5 articulations in the pelvis?
Hip joint (head of femur and acetabulum)
Sacroiliac joint (sacrum and ilium)
Pubic symphysis (two pubic bones at front - very little movement)
Lumbosacral joint (between L5 vertebrae and sacrum)
Sacrococcygeal joint
What is the acetabulum?
Where the ilium, ischium and pubis of the hip bone fuse - socket of the hip joint in the pelvis
What 5 bony landmarks of the pelvis are used as surface landmarks?
Iliac crest
anterior superior iliac spine
Iliac tubercle
Pubic tubercle
Inguinal ligament
Mid-inguinal point
What is the iliac crest as a landmark?
When palpated from the back, line drawn between the iliac crests is their highest point (intercristal line) marks L4/L5 disc space
Where lumbar puncture or epidural injection is performed
What is the anterior superior iliac spine?
What is the pubic tubercle?
Most anterior part of the ilium
Most medial part of the pubic bone
Both are palpable in most people
What is the iliac tubercle?
Most lateral point of the ilium
Line drawn between them (intertubercular line) marks lower third of abdomen
So separates suprapubic from umbilical and iliac fossae from flanks
Where does the inguinal ligament run?
From anterior superior iliac spine to pubic tubercle
What is the mid-inguinal point?
Mid-point of line from ASIS to pubic symphysis
Femoral artery is palpable here
What are the (sometimes distinguishable) differences in the male and female bony pelves?
Wider, circular pelvic inlet for females, narrower, heart shaped in males
Obtuse (>90’) angle formed by inferior pubic rami in females, acute in males
Wider, shorter sacrum in females - longer and narrower in males
What is the purpose and position of the pelvic floor?
What are the 3 primary functions of the pelvic floor?
Supports pelvic organs from below
Separates pelvis from the perineum
1- Prevent herniation of organs inferiorly
2 - control continence of urine and faeces - provide sphincter action
3 - aid in increasing intra-abdominal pressure
What 2 muscles is the pelvic floor made up of?
Coccygeus
(piriformis is also present - idk why but not listed)
Levator ani - made up of 3 unpaired muscles - puborectalis, pubococcygeus, iliococcygeus
What 3 unpaired muscles make up the levator ani and what are their functions?
Puborectalis - u-shaped, attaches to pubic bones anteriorly
Sling around the rectum, controls defecation and micturition when contracts
Most anterior levator ani muscle
Pubococcygeus - posterior and lateral to puborectalis, attaches to pubic bones anteriorly, coccyx and sacrum posteriorly
Iliococcygeus - lateral to the pubococcygeus
Attaches to the spines of the ischium (not ilium) and the coccyx
Which nerve innervates the levator ani?
A branch of S4 nerve and some branches of the pudendal nerve (S2-S4)
Which arteries supply the pelvis?
What are the branches that supply the pelvic viscera?
IL/R internal iliac arteries
Vesical arteries - bladder - prostate and seminal vesicles in males
Uterine and vaginal - females
Middle rectal artery - rectum
Internal pudendal artery - exits pelvis to perineum
Superior and inferior gluteal arteries - exit pelvis to gluteal region
Obturator artery - exits pelvis to lower limb supply
What are the veins of the pelvis?
Several venous plexuses that drain pelvic organs
Unite and mostly drain into the internal iliac veins
What is the nerve supply of the pelvis like?
Somatic, parasympathetic, sympathetic nerves
Sacral spinal nerves come together to form the sacral plexus
Sympathetic fibres for pelvic viscera are derived from the lumbar splanchnic nerves
Which nerves arise from the sacral plexus?
Sciatic nerve - L4-S3 - exits pelvis and supplies lower limb
Pudendal nerve - S2-S4 - somatic nerve - exits pelvis and is major nerve of perineum
Superior and inferior gluteal nerves - exit pelvis and innervate gluteal region
Pelvic splanchnic nerves - S2-S4 carry parasympathetic fibres to pelvic viscera
Where does the sciatic nerve originate from?
Where is it found?
What fibres does it carry?
What does it innervate?
Where does the pudendal nerve originate from?
Where is it found?
What fibres does it carry?
What does it innervate?
Where does the superior/inferior gluteal nerve originate from?
Where is it found?
What fibres does it carry?
What does it innervate?
Where do the pelvic splanchnic nerves originate from?
Where is it found?
What fibres does it carry?
What does it innervate?
What are the two notable flexures of the rectum?
Sacral flexure anteriorly
Anorectal flexure posteriorly
How long is the rectum in an adult?
Approx 12cm
What is the arterial supply of the rectum?
superior rectal artery (branch of inferior mesenteric)
middle rectal artery (branch of internal iliac artery)
inferior rectal artery (branch of internal pudenal, branch of internal iliac)
What is the venous system of the rectum like?
Superior, middle and inferior rectal veins
Branches anastomose with each other to form a venous plexus around rectum and anus
So site of portosystemic anastomoses
What is the perineum?
Immediately superficial and inferior to the pelvic floor
Superficial region between pubic symphysis and coccyx and between medial surfaces of thighs
Can be split into 2 triangles
What are the 2 triangles of the perineum?
urogenital triangle (anteriorly) - complicated, several layers [4]
anal triangle (posteriorly) - contains anus and external anal sphincter
What are the 4 layers of the urogenital triangle?
skin - urethra and vagina opening
perineal fascia - continuation of fascia overlying abdominal wall muscles
superficial perineal pouch - potential space, contains erectile tissues and 3 muscles
perineal membrane -
What is the superficial perineal pouch?
