Urinary System Flashcards
How is urine made?
By filtering the blood.
What does normal urine contain?
Water, salts, Urea, Metabolites and Small proteins.
What does abnormal urine contain?
Large proteins, RBC and glucose.
To be effective the urinary system needs to be?
Adaptable to meet the bodies changing needs.
What are the main components of the Urinary system?
2 kidneys, 2 ureters, bladder and urethra.
Renal refers to what?
Kidneys.
Where are the kidneys located?
Between T12 and L3 and the 11th and 12th rib.
What is the hilum?
A concave notch on the medial surface of the kidneys. This is where vessels go in and out.
What does retroperitoneal mean?
Located on posterior abdominal wall, covered on anterior side by peritoneum.
What are the three supportive tissue layers that protect the kidneys?
The renal fascia (anterior and posterior), the perirenal fat capsule and the fibrous capsule.
What are the three regions of the kidney?
Cortex, medulla and pelvis.
What are the 6 major structural landmarks of the kidney?
Fibrous capsule
Renal cortex
Renal medulla
Renal pyramid
Renal column
Kidney lobe
What structure makes up majority of the kidney lobe?
Nephrons
What order does urine travel through the system?
Papilla –> minor calyx –> major calyx –> renal pelvis –> ureter.
A special type of imaging, that only shows up in the urine is called?
Pyelogram
Where does filtration occur?
In the cortex of the kidney inside the glomerular capillaries.
Where does the Renal artery arise from?
Abdominal aorta.
What vessel delivers blood from the arteries to glomerulus?
The afferent arteriole.
Where does the efferent arteriole carry blood to and from?
From the glomerulus to the peritubular capillaries.
In what order is blood supply INTO the cortex to be filtered?
Abdominal aorta –> renal artery –> series of arteries –> afferent arteriole –> glomerular capillary.
In what order is blood supply AWAY from the cortex after being filtered?
Glomerular capillary –> efferent arteriole –> peritubular capillaries –> series of veins –> renal vein –> inferior vena cava.
What is the nephron?
Microscopic functional unit of the kidney that filters blood and produces urine.
Which kidney is more inferior?
Right.
How many nephrons per kidney?
1 million.
What are the two types of nephron?
Cortical and Juxtamedullary nephrons.
How are nephrons named?
Based on their location.
What is the function of a nephron?
Selectively filter blood, return stuff into the blood and carry waste away from storage and expulsion.
What is each nephron comprised of?
A glomerular capsule, renal tubules and a collecting duct.
What is each nephron associated with?
A glomerulus and peritubular capillaries.
What is the function of the Glomerular capillaries?
Specialised for filtration, therefore they have thin walls with a single layer of fenestrated endothelial cells.
What vessels feed and drain blood to and from the Glomerular capillaries?
Arterioles.
What is the function of the Peritubular capillaries?
Specialised for absorption, they wrap around the renal tubules. They receive filtered blood from the glomerulus via the efferent arterioles and they also receive reabsorbed filtrate from the nephron.
What is the renal corpuscle?
Where the capillary and nephron meet.
Where is the filtration barrier located?
The renal corpuscle.
What wraps around the glomerulus?
The glomerular capsule.
The Glomerular capsule is composed of what two layers?
Outer parietal layer of simple squamous cells and an Inner visceral layer of podocytes.
Between the two layers of the Glomerular capsule is the capsular space, which receives what?
Receives filtrate.
What are podocytes?
Specialised epithelial cells that surround the glomerular capillaries. They are very branched which creates pedicels which form filtration slits between them. Filtered blood (filtrate) goes through these slits and passes into the capsular space.
What is the filtration barrier?
Membrane that lies between blood and capsular space and allows free passage of water and small molecules and restricts passage of most proteins and RBCs.
What are the three layers of the filtration barrier?
Fenestrated endothelium of glomerular capillary, fused basement membrane and filtration slits between the pedicels of the podocytes.
Which two structures form the renal corpuscle?
Glomerulus and glomerular barrier.
What happens after filtration?
urine is waste fluid and solutes are filtered from the blood. Not everything that is filtered is excreted. Some filtrate is reabsorbed and some of what wasn’t filtered is secreted into the nephron.
Urine = ?
Filtered - Reabsorbed + Secreted
What occurs in the Proximal convoluted tubule (PCT)?
Bulk reabsorption.
What surrounds the PCT?
Peritubular capillaries.
What is the structure of the PCT?
Cuboidal epithelial cells, Dense microvilli (brush border) on luminal membrane, highly folded basolateral membrane, leaky epithelium and many mitochondria for active transport.
Explain the structure of the nephron loop?
Thick and thin ascending and descending limb.