S1) Anatomy of the Urinary System Flashcards
check the powerpoint slides and workbook for more images of the anatomy
In terms of anatomical relationships, explain why the left kidney is higher than the right kidney?
- The liver (above the right kidney) is larger than the spleen (above the left kidney)
- Hence, the left kidney is higher because the liver pushes the right kidney down
At approximately what vertebral level would you expect to find the right and left kidneys respectively?
- Left kidney (T11 - L2)
- Right kidney (T12 - L3)
Identify the anatomical relations of the right kidney
4 – Adrenal glands
6 – Duodenum
2 – Hepatic area
7 – Right colon areas
3 – Inferior vena cava
8 – Abdominal aorta
Identify the anatomical relations of the left kidney
4 – Adrenal glands
9 – Small bowel
5 – Spleen
10 – Pancreas
7 – Left colon areas
1 – Stomach
11 – Left renal vein
Identify the complex layers of fascia and fat surrounding the kidney (deep to superficial)
Describe the structure of the following:
- Renal capsule
- Renal fascia
- Renal capsule: tough fibrous capsule
- Renal fascia: encloses the kidneys and the suprarenal glands
Describe the structure of the following:
- Perirenal fat
- Pararenal fat
- Perirenal fat: collection of extraperitoneal fat
- Pararenal fat: mainly located on the posterolateral aspect of kidney
The renal parenchyma can be divided into two main areas.
Identify these
- Outer cortex
- Inner medulla
What are renal pyramids and how are they formed?
The outer renal cortex extends into the inner renal medulla, dividing the kidney into triangular shapes known as the renal pyramids
What is the apex of a renal pyramid called?
A renal papilla
What is a minor calyx and what does it do?
A minor calyx is a structure that is associated with a renal papilla and collects urine from the pyramids
How is a major calyx formed?
Several minor calices merge to form a major calyx
Explain the role of the renal pelvis in the kidney
- Urine passes through the major calices into the renal pelvis, a flattened and funnel-shaped structure
- From the renal pelvis, urine drains into the ureter, which transports it to the bladder for storage
What is the renal hilum and what does it do?
- A renal hilum is a deep fissure which marks the medial margin of each kidney
- Renal vessels and ureter enter/exit the kidney through this structure
Describe the arterial supply of the kidneys
- Receive blood from renal arteries
- Left and right renal arteries arise from the abdominal aorta
Identify the following renal vasculature:
What is the term used to describe the junction between the pelvis of the kidney and the PROXIMAL ureter?
Pelvi-ureteric junction
What term is used to describe the junction between the DISTAL ureter and the bladder?
Vesico-ureteric junction
Describe the venous drainage of the kidneys
- Drained of venous blood by left and right renal veins
- Leave the renal hilum and empty directly into the inferior vena cava
Describe the lymphatic drainage of the kidneys
Lymph from the kidney drains to the lateral aortic nodes
From the hilum, describe the course of the ureter until it enters the bladder
- Ureter arises from the pelvis of each kidney
- descends from psoas major to reach brim of the pelvis
- crosses in front of the common iliac arteries
- runs posters-inferiorly on the lateral walls of the pelvis
- then curves antero-medially to enter the bladder
In females, what does the phrase “water under the bridge refer to?”
The ureter runs underneath the uterine artery
There are three common sites of relative constriction where renal stones can get lodged due to the non-uniformity of the ureter lumen.
Identify these sites
- Pelvi-uteric junction (PUJ)
- Vesico-uteric junction (VUJ)
- When ureter enters pelvis and crosses common iliac artery bifurcation
How long is the urethra in the adult male and female?
4 cm in females
8 cm in males
The male urethra consists of different regions.
Identify them
- Pre-prostatic urethra
- Prostatic urethra
- Membranous urethra
- Penile urethra (aka spongy urethra)
Describe the anatomical location of the pre-prostatic urethra
Pre-prostatic urethra lies between the bladder and prostate
Describe the anatomical location of the prostatic urethra
Prostatic urethra traverses the prostate
Describe the anatomical location of the membranous urethra
Membranous urethra spans from the apex of the prostate to the bulb of the penis (deep peritoneal pouch)
Describe the anatomical location of the penile urethra
Penile urethra traverses the corpus spongiosum of penis
summary of blood supply in the kidneys
what are ureters?
- smooth muscle fibres that propel urine into the bladder
- normally 25-30cm long
- retroperitoneal
- pelvic brim is most vulnerable part
- starts around L1 and runs close to the tip of the lumber and transverse process
- urothelium allows the urter to dilate
what is the vesicoureteral junction
- where the ureter enters the bladder (enters at an “oblique angle” to prevent back flow of urine)
- when the bladder is full, the junction closes
label the bladder
role of rugae in bladder
- muscular folds that contract and expand for recoil and prevents pressure buildup in the bladder
- lined with urothelium
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urothelium
- lines the bladder
- lines the ureter - impermeable to urine
describe the difference between cortical and juxtameduallry nephrons
- cortical - have renal corpuscles in cortex and shorter loop of Henley
- juxtamedullary - larger renal corpuscles in inner third of cortex and long loop of henley extending into the medulla
which type of cells make up the loop of henley
single flattened simple squamous with a few mitochondria
what are principle and intercalated cells
- P cells - few mitochondria and respond to ADH
- I cells - lots of mitochondria and secrete lots of H ions
why is the right renal artery longer than the left
- it has to pass posterior to the vena cava
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what is the role of detrusor muscle in the bladder
- smooth muscle to form internal sphincters
- parasympathetic system can stimulate these muscles and cause contractions
order of the male urethra
20cm
- prostatic → surrounded by the prostate
- membranous → shortest region
- penile
can use a male catheter for both females and males but NO female catheter can be used in a male otherwise it will burst the prostate and you can lose a lot of blood
length of the female urethra
4cm
ureteric abnormalities
- SIDE NOTE- when the urethra splits coming out of one kidney and can go two ways:
- partial → two ureters meet before entering the bladder
- complete → both enter the bladder separately
what do the efferent arterioles of the glomerulus branch into
cortical peritubular capillary beds
how many cm below are the kidneys apart
1cm
