Urinary System part 2

Cards (40)

  • Ureters
    Paired fibromuscular tubes that transport urine from the renal pelvis to the urinary bladder
  • Ureters
    • Abdominal part
    • Pelvic part
  • How does the ureter penetrates the bladder wall?

    The ureter penetrates the bladder wall obliquely
  • Intramural ureter
    Part of the ureter which lies within the bladder from its point of entry in the wall to the orifice in the trigone
  • How does the ureter empties into urinary bladder?

    Each ureter empties into the urinary bladder by a slit opening (urethral orifices) at the cranial margin of the neck
  • Ureters in cattle
    • The ureter divides into two branches directed toward the cranial and caudal poles of the kidneys
    • The primary branches of the ureter subdivide to form 18-22 secondary branches each of which carrying a calix
  • Lower urinary tract
    Consists of urinary bladder, caudal ureter, and urethra
  • Urinary bladder
    • Apex: cranial blind end
    • Body: region situated between the neck and apex
    • Neck: funnel-shaped region between ureteric orifice and urethra
  • Bladder trigone
    Triangular region of the internal urinary bladder formed by the two ureteric orifices and the internal urethral orifice
  • Anatomical location of urinary bladder
    • In carnivores, the bladder extends into the abdominal cavity
    • In large animals, the bladder confined to the pelvic cavity
  • When the bladder enlarges and filled with urine, it becomes pear-shaped
  • As the pressure rises (create the urge to void urine), tension in the bladder wall acts to CLOSE the intramural ureter and preclude urine reflux
  • Detrusor muscle
    Smooth muscle coat of the bladder apex and body, expels urine
  • Smooth muscle sphincter
    Muscle coat of the bladder neck & cranial urethra (internal urethral sphincter), regulates involuntary control of urine flow from the bladder to the urethra
  • External urethral sphincter
    Striated urethralis muscle entirely replaces smooth muscle in the distal third of the urethra, provides voluntary control of urine flow from the bladder to the urethra
  • Blood supply of urinary bladder
    • Receives main blood supply from the caudal vesical arteries, which are branches of the prostatic (male) or vaginal (female) arteries
    • Supplemented cranially by the umbilical arteries
  • Innervation of urinary bladder
    • Receives sympathetic and parasympathetic innervation (autonomic nervous system-motor division)
    • Sympathetic fibers arise from the hypogastric nerves
    • Parasympathetic pelvic nerves are derived from the pelvic nerves
  • When the bladder is full
    There are sensory nerves conveying this information to the brain to increases parasympathetic tone and decreases sympathetic activity
  • Sympathetic influence on the internal urethral sphincter
    Becomes suppressed so that the internal sphincter relaxes and opens
  • Urethra
    Tubular organ that serves as an outlet for urine from the urinary bladder
  • Female urethra
    • Continuous with the bladder, runs caudally on the pelvic floor ventral to the reproductive tract
    • Passes obliquely through the vaginal wall and opens with the external urethral opening ventrally at the junction between vagina and vestibule
  • Male urethra

    • Consists of pelvic part (preprostatic portion and prostatic portion) and penile part
    • Preprostatic portion is short, extends from the internal opening of the urethra to the seminal hillock
    • Prostatic portion is the portion that passes through the prostate gland
  • Males are at greater risk of obstructive FLUTD due to their narrower urethra
  • Cats with FLUTD most often show signs of difficulty and pain when urinating, increased frequency of urination, and blood in the urine
  • In cattle, the ureter is formed by the short passages that lead from renal calyx
  • Muscular part of the bladder
    • Detrusor muscle: smooth muscle coat of the bladder apex and body, expels urine
    • Smooth muscle sphincter: muscle coat of the bladder neck & cranial urethra (internal urethral sphincter)
  • Internal urethral sphincter
    Regulates involuntary control of urine flow from the bladder to the urethra
  • Sympathetic nerves
    Directly cause relaxation and expansion of the detrusor muscle, promoting urine filling
  • Parasympathetic nerves

    Control bladder contractions and the passage of urine
  • Urethral sphincters
    • Internal urethral sphincter: smooth muscle continuous with the detrusor muscle, regulates involuntary control of urine flow
    • External urethral sphincter: striated urethralis muscle, provides voluntary control of urine flow
  • Urinary or urethral incontinence is the loss of voluntary control of urination, usually observed as involuntary urine leakage
  • FLUTD (feline lower urinary tract disease) is a general term used to describe conditions affecting the bladder or urethra of cats, including physical conditions and behavioral disorders resulting in inappropriate urination
  • The two most common types of bladder stones in cats are struvite stones and calcium oxalate stones
  • How does the ureter penetrates the bladder wall
    The ureter penetrates the bladder wall obliquely.
  • How does the ureter empties into urinary bladder?
    Ureter empties into UB by a slit opening (urethral orifices) at cranial margin of neck
  • Struvite stones

    The most common type of bladder stone in cats; made up of magnesium, ammonium, and phosphate; can form in cats with a high urine pH
  • Calcium oxalate stones
    The second most common type of bladder stone in cats; made up of calcium and oxalate; can form in cats with a low urine pH
  • Sympathetic influence on the internal urethral sphincter
    Relaxes and opens the internal urethral sphincter, allowing urine to flow
  • Intramural ureter
    Part of the ureter located within the bladder wall
  • Urine reflux
    Backward flow of urine from the bladder into the ureter and potentially back up into the kidney