Kidney anatomy Flashcards
Between which vertebral levels do the kidneys lie?
T12-L3
What is the maximal vertical movement of the kidneys from end-expiratory to end-inspiration?
40mm
At which vertebral level do the renal hila sit at?
L1 (transpyloric plane)
What is the basic functional unit of the kidney?
Nephron
What is the nephron responsible for?
Regulation of water and soluble substances in the blood through filtration and reabsorption.
The nephron plays a role in homeostasis of what 3 things?
Blood volume
Blood pressure
Plasma osmolarity
How many nephrons are contained within each kidney?
~1 million
What is the first part of the nephron?
Renal corpuscle
What is the renal corpuscle composed of?
Glomerulus and Bowman’s capsule
Where in the nephron does plasma undergo filtration?
Renal corpuscle
Which arteriole of the glomerulus has a smaller diameter?
Efferent
Why does the referent arteriole in the glomerulus have a smaller diameter than the afferent arteriole?
In order to create a hydrostatic pressure gradient within the glomerulus.
The inner visceral layer of the Bowman’s capsule is formed by which types of cell?
Podocytes
What do the podocytes do?
Wrap around capillaries and leave slits between them (filtration slits)
Where does glomerular filtrate pass into after the renal corpuscle?
Renal tubule
What are the parts of the renal tubule?
PCT
Loop of Henle
DCT
Collecting duct
Which part of the kidney does the PCT lie in?
The cortex
Where does the majority of solute reabsorption occur in the renal tubule?
PCT
Reabsorption in the PCT is driven by what?
ATP dependent transporters
What types of cell are found in the PCT?
Cuboidal
Abdundant mitochondria
Multiple microvilli
Which part of the kidney does the loop of hence lie in?
Medulla
What type of cells are found in the descending loop of Henle?
Flat cells
Few mitochondria
Few microvilli
What substance is moved mainly in the descending loop of Henle?
Water by osmosis (no solute movement)
What type of cell is found in the ascending loop of henle?
Cuboidal cells
Impermeable to water
Plentiful mitochondria
Which transporters are found in the ascending loop of Henle?
Na K 2Cl channels
The different functions of the areas of the loop of hence contribute towards what?
Medullary concentration gradient + countercurrent multiplication
What is the function of the DCT?
Variable resorption and secretion to fine-control urine composition.
The DCTs of many nephrons converge into what?
A single collecting duct
The upper collecting duct is lined by what cells?
Columnar epithelium
The lower collecting duct is composed of what cells?
Columnar urothelium
What is present in the walls of the collecting duct to allow for transcellular movement of water?
Aquaporin channels
The number of aquaporin channels present in the collecting duct is controlled by what?
ADH
Many collecting ducts join together to form what?
Several hundred papillary ducts
How many papillary ducts are there per renal papilla?
~30
The contents of the papillary ducts drain into where?
Minor calyx in renal papilla
Several minor calyces join form what?
A major calyx
Where does urine drain from after the collecting ducts?
From the minor calyces to the major calyx and then to the renal pelvis
After the renal pelvis, where does urine drain into?
Ureter
Renin is produced and secreted from where?
Juxtaglomerular cells
Where are juxtaglomerular cells located?
Walls of afferent arterioles
How many layers fo fascia and fat are the kidneys encased in?
4
What are the 4 layers encasing the kidneys from superficial to deep?
Pararenal fat
Renal fascia
Perirenal fat
Renal capsule
Most par arena fat is located where?
Posterolateral aspect of the kidnet
The renal fasciae also envelopes what?
Adrenal glands
The renal fascia is responsible for sending what through the fat surrounding the kidney to hold it in position?
Bundles of collagen
The perirenal fat is continuous with what?
Fat in the renal sinus at the hilum of the kidney.
What is the renal capsule?
Tough fibrous capsule surrounding the kidney
Movements of the kidney during respiration are assisted by what?
Perirenal and pararenal fat
Why are the attachments of the perirenal fascia clinically important?
They prevent extension of perinephric abscess pus
What is the renal fascia attached to inferiorly?
Posterior abdominal wall
What is the renal fascia attached to at the renal hilum?
Vessels and ureter
The parenchyma of the kidney consists of what?
Outer renal cortex
Inner renal medulla
What are the 6 anterior relations of the left kidney?
Left adrenal gland
Spleen
Stomach
Pancreas
Left colic flexure
Jejunum
What are the 4 anterior relations of the right kidney?
Right adrenal gland
Liver
Duodenum
Right colic flexure
What are the 8 posterior relations of the left kidney?
Diaphragm
11th + 12th rib
Psoas major
Quadratus lumborum
Transversus abdominis
Subcostal nerve
Iliohypogastric nerve
Ilioinguinal nerve
What are the 8 posterior relations of the right kidney?
Diaphragm
12th rib
Psoas major
Quadratus lumborum
Transversus abdominis
Subcostal nerve
Iliohypogastric nerve
Ilioinguinal nerve
What is the arterial supply to the kidneys?
Renal arteries
At what vertebral level do the renal arteries arise?
L2
Which renal artery is longer?
Right renal artery (aorta sits to left of midline)
The kidneys receive what percentage of the cardiac output?
20%
The right renal artery passes behind which structures before entering the right kidney?
IVC
Right renal vein
Head of the pancreas
2nd part of the duodenum
The left renal artery passes behind which structures before entering the left kidney?
Left renal vein
Body of pancreas
Splenic vein
The left renal artery is crossed anteriorly by what?
Inferior mesenteric vein
Where are the interlobular arteries of the kidney situated?
Either side of the renal pyramids.
The inner 3rd of the cortex is supplied by what vasculature?
Vasa recta
The renal vein is anterior to what at the renal hilum?
Renal artery
Which renal vein is longer?
Left (IVC sits to the right of the midline)
The left renal vein receives which other veins?
Left gonadal vein
Left suprarenal vein
Where do the left and right renal veins drain into?
IVC
Which nodes drain the left kidney?
Left lateral aortic lymph nodes
Which nodes drain the right kidney?
Right canal lymph nodes
What is the innervation of the kidney?
Renal plexus
Where do the nerve fibres enter the kidney?
At the hila
Sympathetic nervous stimulation triggers what in the kidneys?
Vasoconstriction + reduced renal blood flow
Sensory input from the kidney travels to which spinal levels?
T10-L1 nerves
Which dermatomes can receive referred pain from the kidneys?
Posterior lumbar/ flank region
The renal plexus if formed by filaments from which areas?
Coeliac ganglia and plexus
Aorticorenal ganglia
Aortic plexus
Lower thoracic splanchnic nerves
1st lumbar splanchnic nerve
