Module 7 : Urinary Tract Flashcards
kidneys - 3 stages of development
- arise from the mesoderm
- pronephros, mesonephros, metanephros
pronephros
- form early in the fourth embryological week
- non functioning
- rudimentary
mesonephros
- form late in the fourth embryological week
- function as interim kidney (in-between)
- becomes the mesonephric duct
mesonephric duct
- male > epipdymis, vas deferens, ED
- female > mullein duct > uterus, vagine (NOT FROM MESONEPHRIC DUCT)
metanephros
- permanent kidney
- forms in the fifth week of gestation
- FUNCTION begins about eight weeks gestational
- during fetal growth kidneys migrate from pelvis to abdomen (12-15)
+ result of rapid caudal growth and not really migration
ureters
- develop from the mesonephric duct (wollfian duct) - 4 weeks gestation
- incorportated into bladder trigone
urinary bladder
- develops from urogenital sinus
- continuous with allantois
- infants and children - bladder is abdominal organ and becomes true pelvic after puberty
allantois
- develops from yolk sac
- becomes urachus
- becomes median umbilical ligament
urachus
- pathway bladder travels through after puberty to reside in the true pelvis
kidney location
- retroperitoneal (perirenal space)
- parallel to psoas muscle
- right kidney lower than left due to liver
- IVC and aorta more anterior
kidney lie
- oblique lie in paravertebral gutters
- UPPER POLES MORE MEDIAL AND POSTERIOR THAN LOWER POLES
- MEDIAL MARGINS MORE ANTIEOR THAN LATERAL MARGINS
ureters location
- enter posterolateral aspect of bladder
- ANTERIOR TO ILIAC VESSELS
ureters size
- 2-8mm in diameter (narrow close to bladder)
- 30cm in length
bladder location
- extraperitoneal (outside peritoneum)
- posterior to symphysis pubis
- empty stat - sits in true pelvis
- distended state - into false pelvis/ abdominal cavity
- superior to prostate
- anterior to rectum
- anterior to uterus
kidney shape and structure
- bean shape RENIFORM
- lateral aspect is convex and medial aspect concave
- has 4 layers of supportive tissue
kidney size
- adults
+ length 9-12 - children
+ vary with age
kidney supportive tissue layers - inner to outer
- capsule
- perirenal fat
- renal fascia
- pararenal fat
kidney capsule
- thin and fibrous
- specular reflector
perirenal fat
- continuous with renal sinus
renal fascia/ grotas fascia
- anchor kidney to posterior abdominal wall
- ptosis = kidney falls with fascia tears
kidney parenchyma
- functional tissue
- 2 parts
+ cortex
+ medulla
kidney cortex
- outer portion below renal capsule
- site of urine production
- contain functional unit (nephrons)
- arches over renal pyramids
- columns known as COLUMNS OF BERTIN
kidney medulla
- inner portion
- consists of pyramids
+ triangular structures (8-18)
+ base directed toward sinus
+ apices open into renal sinus (minor calyces)
kidney sinus
- fatty central portion
- continuous with perirenal fat
- contains calyces (major and minor), renal pelvis, vessels, nerves
minor calyces
- 8-18
- receive urine from pyramids
major calyces
- INFUNDIBULA
- 2-3
- join to form renal pelvis
+ renal pelvis leaves sinus as ureter
hilum
- slit like entrance
- from anterior to posterior in hilum
+ renal vein
+ renal artery
+ ureter
+ third branch of renal artery
ureters
- long mucosal lined tubes
- right ureter shorter than left (right kidney lower than left)
- peristalsis and gravity transport urine
- 3 natural points of narrowing
3 natural points of narrowing in the ureter
- UPJ
- pelvic brim
- UVJ
UPJ
- ureteropelvic junction
- junction of renal hilum and proximal ureters
- first point of natural narrowing
pelvic brim/iliac vessels
- ureters are posterior to iliac vessels and can become compressed between them and the pelvic brim
- second point of natural narrowing
UVJ
- ureterovesicle junction
- entrance of ureters into bladder
- third point of natural narrowing
- narrowest
bladder shape and size
- dependant on urine volume
- capacity = 300/500ml
- volume = AP x L x W x 0.52
- post vid < 100ml not significant
bladder lining
4 layers \+ mucosa \+ submucosa \+ muscle \+ serosa
bladder lining - mucosa
- inner layer containing rugae
bladder lining - submucosa
- connective tissue
bladder lining - muscle
- detrusor muscle
- 3 layers
bladder lining - serosa
- peritoneum covering superior surface
trigone
- located on base/posterior surface bladder
- triangular area between the openings of the ureters urethra
- constant shape and position
bladder neck
- urethral orifice
- constant shape and position
apex
- most anterior and superior portion of bladder
- site of median umbilical ligament attachment
- changes with bladder fullness
urethra
- membraneous canal exiting the bladder at the trigone
- females = cancel pierces the urogenital diaphragm
- males = longer, 3 areas (prostatic, membraneous, penile)
blood supply to kidneys
renal arteries»_space; segmental arteries»_space; interloper arteries»_space; arcuate arteries»_space; interlobular arteries»_space; afferent arterioles»_space; glomerulus
renal arteries
- arise form lateral aspect of the abdominal aorta just below the level of the SMA
- supply 1/4 of total cardiac output to kidneys
- divide into segmental arteries
segmental arteries
- divide into interlobar arteries
interlobar arteries
- travel between the pyramids
- branch into arcuate arteries
arcuate arteries
- at the base of the pyramids
- branch into interlobular arteries
interlobular arteries
- travel in the renal cortex
- branch into afferent arterioles
afferent arterioles
- carry blood into the the glomerulus of the nephron
kidney capsule - US appearance
- echogenic line bordering cortex
cortex - US appearance
- homogeneous
- even thickness
- echogenicity equal or slightly less echogenic than the liver
medulla - US appearance
- triangular
- hypoechoic
- equidistant
Corticomedullar junction - US appearance
- pulsation and bright reflection of arcuate arteries
- marker for measuring cortical thickness
sinus - US appearance
- highly echogenic central area
- over hydration = small echo lucent areas within the sinus
vessels - US appearance
- linear anechoic tubes
- best assessed in transverse
cortex look - neonates
- more echogenic
- thin compared to pyramids
pyramids look - neonates
- hypo echoic and large
sinus look - neonates
- indistinct
- very little fat
BY 6 MONTHS SHOULD LOOK LIKE ADULT
ureters - US look
- difficult to visualize unless dilated
- anechoic tubular structures
- utreteral jets
+ indicate flow of urine is not obstructed
bladder - US look
- appears cystic/anechoic
- transverse
+ superior - appears rounded
+ inferior - square - when distended walls appear thin and smooth
- check for wall irregularities
check for jets when?
- if ureters dilated or hydronephrosis
if space occupying region in bladder check what?
- kidneys
function of kidney
- remove metabolic waste by producing urine
- balance amount of water and electrolytes leaving and entering the body
- maintains blood pressure
how much fluid does the kidney process ?
- 180L/day
- 99% returned to body 1% in urine
nephron
- functional unit of the kidney
- filter blood and produce urine
- milions in the kidney
- 2 types
2 types of nephrons
- juxtamedullary (deep)
- cortical (superficial)
2 main components of the nephron
- renal corpuscle
- renal tubule
renal corpuscle
- network of pros capillaries (glomerulus)
- membrane filtration slits (Bowmans capsule)
renal tubule
- proximal convoluted tubule (PCT)
- distal convoluted tubule (DCT)
- loop of henle
- collecting duct
function of nephron
- controlling blood concertino and volume
- regulate pH (electrolyte)
- removing toxins
+ osmosis and active transport
route of blood to nephron
renal artery»_space; interlobar artery»_space; arcuate artery»_space; interlobular artery»_space; afferent artery»_space; glomerulus
3 processes in urine production
- filtration
- reabsorption
- secretion
glomerular filtration
- afferent arteriole transport blood to glomerulus
- increased pressure forces water and dissolved substances through membrane
- filtrate passes through an opening at bottom of Bowmans capsule and enters renal tubule
- RBS do not pass through membrane but leave via efferent article
tubular reabsorption
- nutrients in filtrate are absorbed back into the blood stream
+ water glucose vitamins - reabsorption occurs via peritbular cappilares PCT ascending and descending loop of henle
tubular secretion
- waste secreted into DCT
ADH (antidiuretic hormone)
- secreted by posterior pituitary
- aids in retaining water in body
- decrease in blood volume stimulates release of ADH
aldosterone
- secreted by adrenal cortex
- acts on PCT
- controls rate of sodium reabsorption
+ increased in the blood = increased water = increased blood volume - decrease in blood volume stimulates the formation of angiotenisisn
- influenced by angiotensin system
renin
- secreted by juxtaglomerular capsule
- acts as a catalyst
+ renin (released by kidneys) stimulates formation of angiotenisisn
+ angiotensin stimulates release of aldosterone - respond to decrease in blood pressure
juxtaglomerular apparatus
- located at point where DCT afferent and efferent arteriole come in contact
- granular cells (afferent) release renin
- macular densa cells (DCT) inhibit renin release
- regulates blood pressure
lab tests
- waste products accumulate in blood with kidney disfunction
- 60% loss of renal function before blood tests are elevated
- only need one kidney to live
blood tests
- serum creatinine
- blood urea nitrogen
- serum electrolyte
serum creatinine
- end product of muscle creatine phosphate metabolism
- appears in blood levels constant
- easily excreted by the kidney
- MORE SENSITIVE THAN BUN
- increased values renal failure, chronic nephritis, urinary tract obstruction
blood urea nitrogen
- BUN
- end product of protein metabolism
- formed in liver from ammonia and readily secreted by the kidneys
- reflects protein intake and renal excretory capacity
- increased levels in renal dysfunction and dehydration
- decreased levels in severe hepatic damage malnutrition and over hydration
serum electrolytes
- chloride, potassium, sodium, bicarbonate
- increases in acute renal failure glomerularnephritis
- decreased chronic and acute renal failure
urine tests
- RBC
- WBC
- pyuria
- proteinuria
- pH
- Specific gravity
red blood cells
- inflammation tumors calculi
white blood cells
- infection
- inflammation
pyuria
- pus
- indicates infection
proteinuria
- protein in urine
- nephritis
- polycystic disease stones carcinomas
pH
- acidic = increased hydrogen ions
- alkaline = decreased ions, stones
specific gravity
- ability to concentrate urine
- low levels in renal failure
- increased levels in decreased urin output (dehydration)
