Anatomy of The Urinary System Flashcards
List 4 functions of the kidneys
- Excretion of waste products and drugs
- Regulation of body fluid volume and ions, acid base balance
- Endocrine: makes Renin, EPO and Prostaglandins
- Metabolism: Vit D activated, catabolism of Insulin, PTH and Calcitonin
Describe the anatomical location of the kidneys
How much does one weigh?
Retroperitoneum on posterior abdominal wall, either side of vertebral column, between T12 and L3
140g
The kidneys are partially protected by which 2 ribs?
At what vertebral level is the Hilum
What percentage of the Cardiac Ouput does the kidney use?
11 and 12
Hilum at L1
20-25%
Why is right kidney slightly lower?
Pushed down by liver
At what level do the Ureters start moving Medially towards bladder?
At level of Ischial spine
What are the layers around the kidney?
From deep to superficial
- Renal Capsule
- Perirenal fat
- Renal/ Garrotter’s fascia
- Pararenal/ Paranephric fat
Is the kidney held in place?
What do the surrounding layers do?
No, but the fat layers around it cushion it
What do the Renal Vein and Renal Artery drain into/ branch off of?
Vein- IVC
Artery- Abdominal Aorta
The kidney is organised into Renal Lobes.
What are the 2 parts of the Renal Lobe?
What do you call the region between the lobes?
(Outer) Cortex and (Inner) Medulla
Renal Column (Help to support everything)
The Nephrons start in the Cortex and feed into the Collecting Ducts which travel down and through the Medulla.
Describe how the Collecting ducts feed into the Ureter
Collecting ducts feed into Minor Calyces which feed into Major Calyces.
These feed into Renal Pelvis, where urine accumulates before feeding into Ureter
Compare the 2 types of Nephrons
Cortical Nephrons: 85% of nephrons, short Loop of Henle
Juxtamedullary Nephrons: 15%, Longer Loop of Henle, which descends further down (better for concentrating urine)
What 2 structures make up a Renal Corpuscle
- Glomerulus
- Bowman’s capsule
What cells sit on top of the vessels in the Glomerulus?
What do they do?
Podocytes have foot like projections that wrap around capillaries and creat slits between them
Outline the route of fluid from PCT to Minor Calyces
- PCT
- LoH (3 parts)
- DCT
- Collecting Duct
- Minor Calyces
What is the Renal Pyramid?
The medullary part of the Renal Lobe
What are 3 parts of the Loop of Henle
- Thin descending limb
- Thin ascending limb
- Thick ascending limb
The arteries supplying the nephrons all branch off of which artery?
Which arterioles branch off of the same artery?
Arcuate arteries branch off of the Interlobar artery
The Afferent and Efferent Arterioles (To and away from glomerulus) come from the Interlobular Artery
Which blood vessels cover and wrap around the Cortical Nephrons?
What do they branch off of?
Peritubular capillaries from Efferent arteriole
Juxtamedullary Nephrons have Peritubular capillaries just like the Cortical Nephrons.
What other vessel do they have that the Cortical Nephrons don’t?
The Vesa Recta (An extended Peritubular capillary that covers the longer LoH)
Which cells line the DCT as it passes in contact with the Glomerulus?
What do they do?
- Macula Densa, sense how ‘salty’ the fluid is, to determine the appropriate flow of blood
- Constrict Afferent/ Efferent arteriole
- Send signal to Granular/ Juxtaglomerular cells to make Renin
The Superior Mesenteric Artery runs over which Renal vessel?
Renal Vein
Which renal vessels are longer on 1 side
Right Renal artery> Left Renal artery
Left Renal Vein> Right Renal vein
Outline the Arterial branching into the Kidney
Renal artery-> Segmental artery-> Interlobar artery-> Arcuate artery-> Interlobular artery-> Afferent arteriole-> Glomerulus-> Efferent arteriole-» Vasa Recta and Peritubular capillaries
Outline the Veinous drainage of the Kidney
Peritubular capillaries and Vasa Recta-> Interlobular Vein-> Arcuate Vein-> Interlobar Vein-> Renal Vein
What is the Juxtaglomerular apparatus formed by?
What does it do?
The proximity of the Glomerulus to the Distal Convoluted Tubule
Senses fluid composition and tells kidney to absorb less/ more water
State the length and diameter of the Ureters (have smooth muscle fibres)
Where are they in relation to the peritoneum?
Where are they in relation to the Transverse processes of the lumbar vertebrae?
25-30 cm long and 1.5 mm in diameter
Retroperitoneal, lateral to transverse processes of lumbar vertebrae
State the 3 segments of the Ureter beyond the Pelviureteric junction, PUJ (where Renal Pelvis becomes Ureter)
- Abdominal
- Pelvic
- Intramural
Where is the most common area of Ureteric injury?
Near the pelvic brim
Do the ureters enter the badder posteriorly, anteriorly or laterally
Posteriorly?
What do we call the junction where ureter enters bladder
Vesico-ureteric junction
What 3 structures make up the Trigone of the bladder?
Superiorly: 2 Ureteric openings
Inferiorly: Internal Urethral Meatus (internal urethral sphincter)
Describe how urine reflux into ureter is prevented?
A flap that closes when urine pushes against it when entering bladder at oblique angle
The bladder is made up of 1 large thick muscle called the Detrusor muscle.
What are the folds of this muscle called? What do they do?
Rugae, contract and expand
How much can the bladder hold on average?
When empty, what structure does the bladder rest on?
Where is this structure in Men and Women?
750ml
Rests on Pubic Symphysis; Men- In front of Rectum, Women- In front of Vagina, Uterus, Rectum)
What are the bladder, ureters and renal pelvis lined with internally?
Urothelium
