Kidneys and Suprarenal Glands - Anatomy Flashcards
What vertebral level are the kidneys located?
T12 to L3
Why is the right kidney slightly lower?
Due to presence of liver
What is the hepatorenal recess?
Space between right kidney and liver
Where are the suprarenal glands found?
On superior aspect of R and L kidneys
Are the kidneys intra or retroperitoneal?
Retroperitoneal –> parietal peritoneum and substantial amount of fat has to be removed to see kidneys
Where is the hilum of the kidneys?
On medial aspect
What is the hilum of the kidneys infiltrated with?
Fat (renal sinus)
Describe the layers of fat and fascia surrounding the kidneys?
Renal capsule is a tough fibrous capsule encasing the kidneys
- Perirenal fat surrounds kidneys
- This is surrounded by layer of perirenal fascia
- This is surrounded by pararenal fat
- Parietal peritoneum overlies this
What structures enter the kidney hilum?
- Renal vein
- Renal artery
- Ureter
Describe the order of structures entering and leaving kidney hilum?
- Renal vein enters most anteriorly
- Renal artery just posterior to renal vein
- Ureter enters most posteriorly
Where does the renal vein empty into?
IVC
Where does the renal artery come from?
Abdominal aorta
As the renal artery approaches the hilum, what happens?
It branches into segmental arteries that enter the hilum
What side of the abdominal aorta does the IVC lie?
On the right (but actually left looking at it)
Describe the route of the left renal vein and the right renal vein?
Left –> Crosses over abdominal aorta (due to IVC being on right)
Right –> Goes straight to right kidney
Where do the gonadal arteries emerge from?
From abdominal aorta (just below where left renal vein crosses over abdominal aorta)
Where does the right gonadal vein drain into?
Directly into the IVC
Where does the left gonadal vein drain into?
The left renal vein before entering the IVC (as left renal vein is longer)
What can the kidney parenchyma be divided into?
- Outer cortex
2. Internal medulla
What is the internal medulla composed of?
- Renal pyramids
- Sections of cortex that project into medulla (renal columns) –> this divides medulla into triangular shapes (the renal pyramids)
What is found at the apex of each renal pyramid?
Renal papilla
From the renal papilla, what do we open out into?
A minor calyx (surround the apex of the renal pyramids)
What do the minor calyces join to form?
2 or 3 minor calyces join to form major calyces
What do major calyces converge to form?
The renal pelvis
What is the renal pelvis?
Dilated region of the collection system
What does the renal pelvis then narrow to form?
Ureter
Where do the suprarenal glands receive blood supply from?
3 arteries:
- Superior suprarenal artery
- Middle suprarenal artery
- Inferior suprarenal artery
Where is the superior suprarenal artery derived from?
The inferior phrenic artery
Where is the middle suprarenal artery derived from?
Directly from the aorta
Where is the inferior suprarenal artery derived from?
From the renal artery
What is the quadratus lumborum?
The deepest abdominal muscle found in the lower back
Where is the quadratus lumborum found?
Found in the lower back between the top of the pelvis and the lowest rib
What is the psoas major and minor?
Major –> Found on medial aspect from the lateral aspect of the lumbar vertebra that goes on to attach to femur
Minor –> Tendinous slip sat on anterior surface or psoas major (absent in 20%)
Where is the iliacus muscle?
In the iliac fossa
What does the iliacus muscle join with?
The tendon of the psoas muscle (ilio-psoas)
Common attachment point on the femur
What are the crura?
The crus of diaphragm (pl. crura), refers to one of two tendinous structures that extends below the diaphragm to the vertebral column. There is a right crus and a left crus, which together form a tether for muscular contraction.
What nerve underlies rib 12?
Subcostal nerve
This goes on to supply some muscles of the lateral abdominal wall
What nerve is found at L1?
Common stalk splits into iliohypogastric nerve (superior) and ilioinguinal nerve (inferior)
What nerve is sat on top of the psoas major?
The genitofemoral nerve
What does the genitofemoral nerve split into?
- Genital branch
2. Femoral branch
What does the femoral branch supply?
The skin of the upper anterior thigh
What does the genital branch supply?
Enters the deep inguinal ring, inguinal canal and superficial inguinal canal to supply skin around genital region
What nerve is found on the medial aspect of the pelvis?
Obturator nerve
What is the obturator nerve responsible for?
- The sensory innervation of the skin of the medial aspect of the thigh
- The motor innervation of the adductor muscles of the lower limb (external obturator)
What does the perirenal fascia enclose?
The kidneys and the suprarenal glands
What is the job of the minor calyces?
Collect urine from the pyramids
Where do the renal arteries arise from?
The abdominal aorta, immediately distal to the origin of the SMA
Which renal artery is longer? Why?
The right renal artery is longer due to the anatomical position of the abdominal aorta (slightly to the left of the midline)
The right renal artery crosses the vena cava posteriorly
What is the avascular plane of the kidney?
An imaginary line along the lateral and slightly posterior border of the kidney, which delineates the segments of the kidney supplied by the anterior and posterior divisions of the renal artery.
It is an important access route for both open and endoscopic surgical access of the kidney, as it minimises the risk of damage to major arterial branches.
The renal artery branches are anatomical end arteries. What does this mean?
There is no communication between vessels
Why is it clinically important that the renal artery branches are anatomical end arteries?
Trauma or obstruction in one arterial branch will eventually lead to ischaemia and necrosis of the renal parenchyma supplied by this vessel.
What does the renal artery divide into?
Anterior and posterior artery
These then divide into segmental arteries
What do the branches of the renal artery eventually form?
Afferent arterioles that form a capillary network –> the glomerulus (where filtration takes place)
These capillaries then come together to form efferent arterioles
In the outer 2/3 of the renal cortex, what do the efferent arterioles form?
A peritubular network –> supplying the nephron tubules with oxygen and nutrients
What is the inner 1/3 of the cortex and medulla supplied by?
Vasa recta (long straight arteries)
What are the ureters?
2 thick tubes which transport urine from the kidneys to the bladder
Where do the ureters arise?
As a continuation of the renal pelvis
Where does the renal pelvis receive urine from?
The major calyces
What is the ureteropelvic junction?
Where the renal pelvis narrows to form the ureter
How do the ureters descend into the pelvic cavity?
Through the abdomen, along the anterior surface of the psoas major
At the area of the sacroiliac joints, the ureters cross the pelvic brim, thus entering the pelvic cavity. At this point, they also cross the bifurcation of the common iliac arteries.
How do the ureters travel through the pelvic cavity?
The ureters travel down the lateral pelvic walls. At the level of the ischial spines, they turn anteromedially, moving in a transverse plane towards the bladder.
What happens once the ureters reach the bladder?
They pierce its lateral aspect in an oblique manner –> angle creates a one way valve, preventing the backflow of urine
Why is the course of the ureters clinically important?
They travel close to other structures in the pelvis. They must be identified during pelvic surgery to ensure that they are not accidentally damaged.
What care must be taken in regards to the ureters in females?
As they cross the pelvic brim, the ureters are in close proximity to the ovaries. Care must be taken not the damage the ureters during an oophorectomy, especially during the ligation of the ovarian arteries.
They also run underneath the uterine artery. Care must be taken not to damage the ureters during a hysterectomy (where uterus and uterine artery are removed).
What care must be taken in regards to the ureters in males?
In men the vas deferens cross the ureters anteriorly.
How have the ureters developed?
Has developed via the ureteric bud from the mesonephric duct, and then followed the kidney during its ascend to the final lumbar position in the retroperitoneum.
What can the arterial supply to the ureters be divided into?
Abdominal and pelvic supply
What is the abdominal supply of the ureters?
Renal artery, testicular/ovarian artery, and ureteral branches directly from the abdominal aorta
What is the pelvic supply of the ureters?
Superior and inferior vesical arteries.
How is nervous supply to the ureters delivered?
Via the renal, testicular/ovarian and hypogastric plexuses
Where do sensory fibres from the ureters enter the spinal cord?
T11 - L2
Ureteric pain is referred to those dermatomal areas
What is a ureteric calculus?
A kidney stone
The presence of a solid stone in the urinary tract, formed from minerals within the urine.
What are dangers of kidney stones?
These can obstruct urinary flow, causing renal colic (an acute and severe loin pain) and haematuria (blood in the urine).
Do a CT scan!
Where are the 3 common places for kidney stones to get stuck?
3 constrictions of ureters:
- Uretopelvic junction
- Pelvic brim
- Where urethra meets bladder
