B5.077 Human Urinary System Flashcards
components of the urinary system
kidney x 2
ureter x 2
urinary bladder
urethra
differences between male and female urinary systems
male: has prostate and longer ureter
female: shorter ureter and lies anterior to uterus and ovaries
functions of the urinary system
waste excretion via liquid
normal urine specs
0.4-2L daily
bladder volume = 300 - 400 mL
duration of urination = 21 +/- 13 s
polyuria
> 2.5 L /day
oilguria
0.1-0.4 L/day
anuria
< 0.1 L/day
overview of basic renal function
- removal of waste products and drugs from the body
- balance the body’s fluids
- regulation of plasma ionic composition
- regulation of plasma osmolarity
- regulation of plasma volume
- regulation of plasma hydrogen ion concentration (pH)
- release of hormones (renin) to regulate BP
- control production of RBCs
- engaged in vit D activation
what is a staghorn calculi
whole calix filled with kidney stone structure
need to be surgically removes
epidemiology of kidney stones
occur in 1/10 people at some point in their life
exhibit “time effect” aka take about 10 years to develop
what are kidney stones due to
increased excretion of stone forming components such as calcium, oxalate, urate, or cystine
resolution of kidney stones
< 4 mm have 80% chance of spontaneous passage
> 8 mm have 20% chance of spontaneous passage, require additional treatment
types of calcium stones and their prevalence
- calcium oxalate 80%
- calcium phosphate 5-10%
- uric acid 5-10%
- struvite 10-15%
- cysteine 1-2%
- xanthine (very rare)
calcium oxalate findings
acidic urine
X ray +
calcium phosphate findings
alkaline urine
x ray +
uric acid findings
acidic urine
x ray -
struvite findings
due to infection
infectious urine
x ray +
cystine findings
genetic defect
x ray +
xanthine findings
x ray -
what is PKD
polycystic kidney disease
an inherited genetic disorder which causes clusters of cysts to develop primarily within kidneys
kidney enlargement and loss of function over time
cysts may also occur in liver, seminal vesicles, and pancreas
type 1 PKD
autosomal dominant
PKD1 85%
PKD2 15%
type 2 PKD
autosomal recessive
PKHD1 incidence 1:20,000
carrier 1:70
examples of kidney tumors
- renal cell carcinoma, 80-90%
- transitional cell carcinoma 5-10%
- renal sarcoma, <1%
- wilms tumor, nephroblastoma
- renal adenoma
- oncocytoma
- angiomyolipoma
describe the structure of the ureter
muscular tube, 25-30 cm x 3-4 mm
layers: lumen, transitional cells, lamina propria, inner muscle (longitudinal), outer muscle (circular)
muscle contraction in the ureter
occurs every 10-15 s
prevalence of ureter duplication
0.8-0.9%
discuss the ureter blood supply
receives blood from multiple arteries spanning from renal down to the vaginal
during surgical resection, have to be careful about severing blood vessels
physiologic narrowings of the ureter
- uretopelvic junction (UPJ)
- crossing over the iliac vessels
- uretovesical junction (insertion into bladder wall)
stones get stuck here
what are some sources of UPJ obstruction
- intrinsic (developmental problem in muscle)
- ureteral hypoplasia
- abnormal or high insertion of ureter into the renal pelvis (angular junction)
- crossing lower-pole renal vessel (usually artery)
- rotation of the kidney
consequence of UPJ obstruction
hydronephrosis
occurs in 1:1500 live births
what is important to know about the orientation of the bladder in females
right next to cervix
common site of cervical cancer metastasis
what is the trigone
area of muscle between 2 ureteral openings and neck of bladder
sensitive to bladder expansion
neuronal control of sphincters
internal = involuntary external = voluntary
layers on bladder histology
lumen, transitional epithelium, lamina propria, muscular layer, adventitia with fat
why is the transitional epithelium of the bladder important
contains multinucleated umbrella cells which make glycans to seal the bladder surface
blocks toxins from getting into deep tissue
what is the most important layer of the bladder
muscular layer
run through the micturition reflex
- stretch receptors detect bladder filling and transmit afferent signals to spinal cord via pelvic nerve
- signals return to bladder from S2 and S3 spinal cord segments via parasympathetic fibers in pelvic nerve
- efferent signals excite detrusor muscles (contraction)
- efferent signals relax internal urethral sphincter, urine is involuntarily voided if not inhibited by brain
- for voluntary control, micturition center in pons receives signals from stretch receptors
- if it is time to urinate, pons returns signals to spinal interneurons that excite detrusor and relax internal sphincter, urine is voided
- if it is untimely to urinate, pons excites spinal interneurons that keep the external sphincter contracted to retain urine in bladder
- later, pons ceases these signals and external sphincter relaxes
hypogastric nerve function
sympathetic control of bladder muscle and internal sphincter
relaxes bladder via NE
contracts internal sphincter via NE
pelvic nerve function
parasympathetic control of bladder muscle
contracts bladder via Ach
pudendal nerve function
somatic control of external sphincter
contracts sphincter via Ach
medical examinations of the urinary bladder
urinalysis
cystoscopy
urodynamic testing
what is urodynamic testing
series of tests of urination, usually done in a doctors office
urine flow, pressure, bladder capacity, and other measurements can help identify bladder problems
components of a urodynamic test
post void residual volume multichannel cytometry uroflowmetry bladder neck EMG urethral pressure profilometry fluoroscopy of the bladder and bladder neck during voiding
2 classes of urinary bladder tumors
papillary
nodular
what is the prostate
walnut sized gland
7-16 grams
secretes alkaline fluid in semen
types of benign prostatic hyperplasia
basal < stromal < grandular
basal = non nodular
stromal = CD34+ fibroblast cells, nodular
glandular = most common, nodular
what is TURP
trans urethral resection of prostate
treatment for BPH
break off pieces of prostate and suck them out
not done much anymore
more common BPH surgery
laser vaporization of the prostate
less bleeding and fewer complications that TURP
epidemiology of prostate cancer
1 in 9 men will develop it (lower than in past due to reduced screening and reduced false positives)
60% are over 65
1 in 41 will die from it
treatment options for prostate cancer
- surgery
- radiotherapy
- chemotherapy
- hormone therapy
- immunotherapy
- targeted therapy
posterior urethra
within body
anterior urethra
outside of body
urethral stricture
can happen in males
narrowing of the urethra resulting in difficulty passing urine through it
what are hypospadias
urine exiting body at wrong place
requires surgery to reroute urine and enable standing urination, correct bend, and make penis look normal
