Urinary System Flashcards
What are the main parts of the urinary system and their brief function? (4)
Kidney: produces urine as by product of filtration
Ureter: transports urine to bladder
Urinary bladder: stores urine
Urethra: conducts urine to the exterior from bladder
What are the main functions of the urinary system? (4)
Regulate blood volume and iconic composition
Regulate blood pressure (amount of water loss and renin)
Regulates blood pH (excretion of H+)
Excretes nitrogenous waste and drugs and toxins
What is the anatomy of the kidney? (location, surrounding structures, 5)
Retroperitoneal
Left: T12-L2
Right: L1-L3 (lower due to liver)
Surrounded by: perirenal fat, renal fascia, pararenal fat
Adrenal gland located on superomedial surface of each kidney
What is the function/ anatomical location of the renal fascia, perirenal fat, and pararenal fat?
Renal fascia: surrounds suprarenal gland, goes between kidney and SRG, important for removal of kidney because you can remove it without affecting the SRG
Perirenal fat: intimate contact with kidney, open inferiorly down to pelvis therefore often infection spreads between these two
Pararenal fat: outside layer
What are the structures of the kidney? (9)
Renal Hilum, renal pelvis (turns into ureteric tube)
Medulla: inner, pyramidal shape
Cortex: outer portion
Lobe: contains medulla pyramid and bit of renal columns
Renal columns: btwn pyramids, extension of cortex
Capsule: outside of cortex
Renal papilla: takes urine to calyces
Calyx: all major calyces aggregate into renal pelvis
What is involved in the arterial and venous blood blow within the kidneys? (5 types)
- Renal artery/vein: both LT and RT from abdominal aorta to kidney and vein back to IVC
- Segmental arteries/veins: branch of renals goes to top and bottom of kidneys
- Interlobar arteries/veins: between lobes, along sides and base
- Interlobular arteries/veins: between lobules
- Arcuate arteries/veins: run along base, NOT continuous, thus if you get a blockage it is bad
What is involved in cortical circulation of the kidney? (4)
Arcuate arteries and veins branch into the interlobular artery/vein between the lobules
Afferent arterioles branch off of these and come in close contact with the nephron/renal corpuscle for filtration
Interlobar arteries/veins carry blood away
What is the nephron? (2)
The basic functional unit of the kidney
1 million nephrons per kidney
What are the structures of the nephron from beginning to end? (9)
Renal corpuscle
Proximal convoluted tubule
Thick descending limb, thin descending limb
Loop of Henle
Thin ascending loop, thick ascending loop
Distal convoluted tubule
Collecting tubule
What are the two major divisions of the nephron?
Cortex and Medulla regions
What are the functions of the nephron?
Blood filtered in the renal corpuscle
Blood cells and large proteins retained by filter (too big)
Low molecular weight proteins, ions, metabolites, dissolved wastes pass through
Water, ions, and useful substances reabsorbed in the renal tubule
What are the two types of nephrons and how are they different?
Cortical nephron: almost all in cortex of the kidney except part of thin and thick limbs
Juxtamedullary nephrons: most of tubular network in the junction and rest in medulla
What is the anatomy of the renal corpuscle? (9)
Afferent arteriole and efferent arteriole
Glomerulus: network of capillaries surrounded by visceral membrane
Bowman’s capsule: lines the inside of RC, parietal layer
Bowman’s space: contains the filtrate
Proximal convoluted tubule: heavily ciliated to up SA, draw more stuff back into the body, gets filtrate from RC
Podocyte: visceral layer, intimate contact with glomerulus creating interdigitary patterns between cells
Mesangial cells
Endothelium
What are the three steps in glomerular filtration? (3)
- Fenestration (pore) of glomerular endothelial cell: prevents filtration of blood cells but allows all components of blood plasma to pass through
- Basal lamina of glomerulus: prevents filtration of larger proteins
- Slit membrane between pedicels: prevents filtration of medium sized proteins
What are the brief functions of the 7 main structures in the nephron? (4)
Renal corpuscle: produces filtrate
Proximal convoluted tubule: reabsorption of organic nutrients, ions, water
Thin limb: reabsorption of water
Thick limb: reabsorption of ions (Na and Cl)
Distal convoluted tubule: secretion of ions, acids, toxins, variable reabsorption of ions and water controlled by aldosterone
Collecting tubules/ ducts: variable reabsorption of water/ ions via ADH
Papillary duct: delivery of urine to calyces
How does urine become concentrated?
Salt gradient concentrates the filtrate: in medullary region there is more osmotic pressure for H20 to leave collecting duct as you go down, and thus water follows out of the urine and concentrates it
What is the blood supply in the cortical nephron?
Efferent arteriole forms capillary bed around tubules
What is the blood supply of the juxtamedullary nephron?
Vasa recta carry away water to preserve salt concentration
Creates countercurrent loop of ion concentration, as you go lower the higher the Na concentration so water moves out
What is the anatomy of the juxtaglomerular apparatus? (6)
Afferent and efferent arterioles
Renal corpuscle and glomerulus
Macula densa cells: at interface of distal convoluted tubule and arterioles, sense BP in afferent/efferent arterioles
Juxtaglomerular cells: by macula densa cells,
What is the function of the juxtaglomerular apparatus and the two important cell types?
Increases filtration rate and elevates BP
Macula densa cells: monitor electrolyte concentration
Juxtaglomerular cells: SMC in the afferent arteriole, secrete renin, renin elevates BP
What is the anatomy of the ureter? (4) What is the purpose of epithelium?
Mucosa: made up of transitional epithelium and lamina propria
Smooth muscle
Outer connective tissue layer
Epithelium allows stretch for accomodation of lots of fluid
What is one issue that can arise from the blood flow to the kidney/ ureter?
SMA may get pushed against LT renal vein and prevent flow so it compromises kidney, adrenals and gonads
What are the three sites of ureteric constriction?
- Ureteropelvic junction: renal pelvis narrows to form ureteric tube and compressed against renal fascia
- Crossing of the iliac vessels
- Ureterovesical (bladder) junction: through detrusor muscle to get into bladder, may constrict
What structure in the bladder is responsible for telling you when you have to pee?
Trigone: neural sensation about distension and amount of urine
What are the layers of the urinary bladder? (4)
Mucosa: transitional epithelium for stretch and lamina propria for vasculature
Submucosa
Visceral peritoneum
Detrusor muscle
What are the anatomical features of the urethra? (4)
Lumen of urethra
Stratified squamous epithelium of mucosa (do not need to stretch because want to expel not hold urine)
Lamina propria containing mucous epithelial cells
LOTS of smooth muscle
What spinal levels does innervation of the kidney and ureters come from?
T10-L1
What are the regions of referred pain in the urinary system? (3)
T10-L1: LION TO GROIN, umbilicus against posterior abdominal wall therefore back pain common
L11-L2: genitals
L1-L2: bladder
Is there referred pain in the bladder?
Not really, because it can expand so far
