Flashcards in Histology Of Urinary Tract Deck (17)
What are the layers of the urinary tract?
- epithelium and lamina propria layers
- contains urothelium layers with uroplakins (which allow for the dome cells to flatten and allow for distention as well as anti-toxic properties)
-amount of layers differs
- 2-3 layers smooth muscles
- very thick in the urinary tract except the urethra
- includes serosa and is only present on the superolateral bladder
What do sympathetics do in the urinary tract?
Inhibits smooth muscle contraction of the ureter and detrusor muscle
Promotes smooth muscle contraction of the internal urethral sphincter and urethra
Controls vasomotor control over arterioles and also enhances sodium reabsoprtion in tubules
**increases in sympathetics will allow the bladder to expand and retain urine, decrease urine frequency**
**decreases in sympathetics will prevent the bladder from expanding and promote urine frequency**
What do parasympathetic do in the urinary tract?
Promotes smooth muscle contraction of the ureter and detrusor muscles
Inhibits smooth muscle contraction of the internal urethral sphincter
May also contribute to the vasomotor regulation of the afferent and efferent arterioles
**increasing parasympathetics promotes voiding of the bladder (increases volume) and the feeling of urgency**
**Decreasing parasympathetics decreases voiding of the bladder (decreases volume) and the feeling of urgency **
What is the purpose of visceral afferents in the urinary tract?
Stretch receptors which detect the degree of distention of the bladder as part of the micturition reflex controlled by the CNS
Pyelonephritis vs cystitis vs urethritis
- infection of the renal pelvis and the calyces which leads to neutrophil accumulation in the CD
- inflammation of the bladder mucosa
- can be caused by infection, immunodeficiency, urinary catheterization and chemotherapy
- chronic cystits can lead to unstable urothelium and benign urothelial changes which leads to transitional cell carcinoma
- infection of the ureters
- most commonly caused by coli form bacteria and chlamydia
- causes pain while urinating and dysuria almost always
- *way more common in females than males since their urethras are smaller
Why is urothelium very unique?
Possess uroplaquin proteins which make up urothelial plaques along the urothelium cells
- forms a lipid bilayer essentially and both protects from the toxic effects of urine and allows the cells of the urothelium to stretch and flatten to move urine
How does development of the urethra differ in women and males?
Women = all of the urethra is generated via the pelvic part of the urogential sinus
Men = prostatic and membranous urethra is derived from the pelvic part IFN the urogential sinus
- spongy urethra = development from phallic portion of the urogential sinus
Where do the sympathetics and parasympathetics for the kidney and abdominal ureters arise from?
Lesser splanchnic nerves (T10-11)= sympathetic
- least (T12) and greater = adrenal glands
Pelvic splanchnic and posterior vagal trunk = parasympathetic
*both combined make up the renal plexus which innervates the kidney*
Where do the sympathetics and parasympathetics for the pelvic ureter, bladder and urethra?
Lumbar Splanchnic nerves (L1/2) = sympathetics
Pelvic splanchnic nerves = parasympathetic
*both of these make up the inferior hypogastric plexus*
**sympathetics also make up the vesicular and prostatic plexi**
What do somatic efferents in the urinary tract do?
Promotes skeletal muscle contractions of external urethral sphincter
Where are the possible constrictions of the urinary track?
1st = where the ureter passes over the inferior renal pole
2nd = ureter passes behind testicular and ovarian vessels
3rd = ureter crosses over external iliac vessels (pelvic part)
4th = ureter traverses the bladder wall (intramural part)
- most common site**
How does visceral referred pain differ between superior and inferior bladder?
Superior = lower abdominal region/ suprapubic region
Inferior = scrotum
The ureter protrudes into the bladder lumen and swells up due to the detrusor muscle clamping down on it.
- is an example OPG a urinary track blockage and leads to hydroureter and hydronephrosis
How does the arterial supply to the kidney and ureter get broken down?
**All are branches from the renal artery except #1 (come off abdominal aorta)**
1) middle suprarenal and inferior phrenic/superior suprarenal arteries = adrenal glands
2) inferior suprarenal arteries = adrenal glands and superior kidney pole
3) renal artery itself = middle and lower poles of the kidney
4) urethral branches = lower pole, ureter
How does the arterial supply to the bladder and urethral get broken down?
**All are branches off the internal iliac artery**
1) superior vesical arteries and umbilical arteries = urinary bladder and distal ureter
2) inferior vesical arteries and prostatic arteries = prostate and epididymis
What is the course of the ureter?
Arises in renal pelvis and travels under gonadal arteries, over the common iliac arteries and under the uterine artery/vas deferens
- because of this course, gynecological procedures often damage the ureter or apply obstruction if not properly.