Renal Flashcards
What are the structures of the renal system?
Where are they located?
Urinary tract has four major structures:
- Kidneys (x2)
- Ureter (x2)
- Bladder
- Urethra
They are all located in the retroperitoneum
List the functions of the renal system
Homeostasis (maintenance of the body’s internal environment) through multiple functions:
- Removal of waste products & drugs: Produces waste as urine to be passed out of the body through urinary tract.
- Blood pH control
- Blood pressure control
- Blood volume control
- Fluid and electrolyte balance
- Stimulates red blood cell production
- Required for absorption of calcium: calcium helps nerves fire (synapses communicate)
Where are the left and right kidneys positioned?
What changes their position?
Position of the Kidneys
- Right kidney (L1-L3)
- Left kidney (T12-L2): left not lower, right lower (by 1 vertebra)
- Kidneys move with inspiration and expiration: as diaphragm contracts (flattens), organs pushed down
List the structures that protect the kidney
- Being in the retroperitoneum
* Posterior to other abdominal organs - Vertebral column (transverse processes)
- Ribs 11 & 12
- Skeletal muscles
- muscles of the back
- muscles of the antero-lateral abdominal wall (3 layers)
- muscles of the posterior abdominal wall
- Paranephric fat
- Renal (deep) fascia
- Perinephric fat
- Renal capsule
Label the diagram
Nephrons in kidney = nephric
Paranephric = outer layer
Perinephric = direclty around (like periodontium)
List the external structures of the kidney
- Superior pole (adrenal gland sits on superior pole)
- Inferior pole
- Renal Hilum
- Renal Artery
- Renal Vein
- Renal Pelvis (which collects urine) - becomes ureter
Label the diagram, including the purple area
Kidney consists of (mainly) an outer cortex and an inner medulla
- Cortex = outside layer of any structure
- Beneath the dashed line everything is the medulla
Note:
- Apex of the renal pyramid = renal papilla
- The sinus has fat, which suspends blood vessels
What is the base unit of a kidney?
How many are contained in a human kidney?
Nephrons are the base unit of the kidney (contained in the renal pyramids)
The human kidney contains roughly 1-1.5 million nephrons
Label the diagram
List the steps of urine drainage from the kidneys
Describe the tube diameter
- Nephron collecting duct
- Minor calyx
- Major calyx
- Renal pelvis
- Ureter
Diameter of urine drainage “tubes” is increasing until a constriction at the pelviureteric junction
The renal calyces are chambers of the kidney through which urine passes. The minor calyces surround the apex of the renal pyramids. Urine formed in the kidney passes through a renal papilla at the apex into the minor calyx; two or three minor calyces converge to form a major calyx, through which urine passes before continuing through the renal pelvis (combination of major calices) into the ureter.
Label the diagram
Describe the changes in diameter
Diameter of tubes increases until constriction at pelviuereteric junction
Label the diagram
Where does the bladder sit? What is its function?
Describe the muscles present in the walls and key points of the bladder, and their function
Bladder sits inside the pelvis (not in the retroperitoneal space anymore)
Only function is to store urine, which it releases via the urethra
Detrusor muscle (smooth involuntary muscle) is present in the bladder’s walls
Function:
- Involuntary - It gives us the urgency to pee.
- It contracts during micturition
Label the diagram
What are two points that differentiate the male urinary tract from the female?
Urethra much longer in males than in females
Only males have an internal urethral sphincter (involuntary) - prevents reflux of semen into bladder
Label the diagram
What are 3 points that differentiate femal urinary tract from males? What does this contribute to?
Females at higher risk of UTI because urethra shorter: roughly 4 cm, so bacteria have a shorter distance to travel
Describe blood supply to the kidney and ureter
Name 3 bilateral branches of the abdominal aorta
- Kidneys get blood supply straight from the aorta: renal arteries
- 5 segmental branches arise from each renal artery to supply nephrons
- The ureter gets a few branches of small arteries because it is so long
Describe venous drainage of the kidney
Are the 3 bilateral branches of the abdominal aorta bilateral as well for the IVC?
NO:
- IVC ascends up the right side of the body (goes to the right atrium)
- Aorta descends down the left side of the body (comes from the left ventricle)
So the left renal vein (which flows directly to IVC) is longer (than the right) since it has to cross over the aorta – much more prone to injuryand compression to affect kidney function
The left suprarenal vein and gonadal vein piggybacks off the left renal vein (whereas on the right they flow directly into the IVC)
