VAna Urogenital

• • Perirenal fat - mass of protective fat surrounding the kidney and holding its place
• • Fibrous capsule - loosely attached (except at the hilus) covering the kidneys
• • Renal cortex - outer layer of the kidney parenchyma beneath the capsule; characterized  by their light color and granular appearance 
• • Renal medulla - inner layer of the kidney parenchyma; characterized by the striated appearance
• • Renal crest - ridge resulting from the complete fusion of the medulla and pyramids
• • Renal calyx - cup-shaped structure receives urine from the renal papillae
• • Renal sinus - space occupied by the ureter, renal blood vessels and nerve entering the kidney
• • Renal hilus - opening to the renal sinus
• • Renal pelvis - expanded proximal end of the ureter
• 1. URETER

  • Muscular tube
  • Divided into abdominal or pelvic part
  • Turns medially to enter the broad uterine ligament in the female and the mesoductus deferens in the male
  • Ends by inserting into the dorsolateral surface of the urinary bladder
  • Length of intramural course prevent reflux of urine into ureter when pressure is raised within bladder but does not hinder further filling of bladder as resistance is normally overcome by peristaltic sonstraction of ureteric wall
  • Peristaltic contractions of the ureteric wall prevents reflux of urine
• 1. URINARY BLADDER

  • Hollow musculomembranous organ
  • Collect and stores urine
  • Varies in form, size, and position depending on amount of urine it contains
  • Usually small, globular organ in pubic bone, extends to abdomen (carnivores) but for large animals, more confined in pelvic cavity
• • Body - main part of the bladder having a dorsal and ventral surface
• • Neck - constricted portion of the bladder continuous posteriorly with the urethra (internal; smooth and involuntary control and external sphincter; ring of striated muscle under voluntary control)
• • Fundus - the blunt, flask-shaped anterior extremity
• • Detrusor muscle - smooth muscle of the urinary bladder
• • Ureter ostium - opening for the ureters
• • Trigone - triangular area in the vicinity of the neck
• • Inner layer = Transitional epithelium (enables walls to expand  when filling urine)
• • Submucosal layer = Elastic tissue and Smooth muscle (arranged in folds to allow expansion)
• • Peritoneum (surrounds bladder, covers only cranial end lying on abdomen)
• 1. URETHRA

  • Tube that conveys urine caudally from the bladder through the pelvic cavity to the outside (female carries only urine, males carry urine, semen, and seminal secretions)
• • Female - urethra is a short tube, opening into the floor of the reproductive tract at the junction of the vagina and vestibule
  • Opening: external urethral orifice
  • Located: urethral tubercle
• • Male - urethra is divided into two parts:
  • Pelvic urethra
  • Penile urethra
• • TESTES - male gonad
  • Produce spermatozoa
  • Produce fluid to transport and protect the sperm
  • Secrete hormone testosterone
  • Cryptorchidism (failure of testes to descend) 
• • SCROTUM pouch where testes are located
  • Left testes usually hangs lower than the right
• • Tunica dartos - (cold) contracts and thickens the scrotal skin, raising the temperature. (Warm) muscle relaxes and turns thinner = cooler
• • Tunica albuginea - (white tunic) strong, white fibrous capsule enveloping the testes
• • Lobules - units of testicles which contain few seminiferous tubules. Separated by septa
• • Seminiferous tubules - hollow structures in which male germ cells differentiate to spermatozoa. Major parts: convoluted (sperm production occurs) and straight seminiferous tubules (does not produce sperm).
• • Rete testis – network of irregular, interconnecting channels.
• • Efferent duct – 8 to 15 channels leading into the head of the epididymis.
• • Epididymis – structure adjacent to the testes.
• • Proper ligament of the testis – connects the tail of the epididymis to the ventral extremity of the testis.
• • Ligament of the tail of the epididymis and scrotal ligament – connects the tail of the epididymis to the tunica vaginalis parietalis.
• • Vaginal tunic – double wall of serous membrane (visceral and parietal around the spermatic cord and testicle in the male. 
• • Parietal vaginal tunic – continuation of the abdominal parietal peritoneum through the inguinal canal.
• • Mesorchium – serosal fold connecting the visceral tunic with the parietal vaginal tunic.
• • Mesoductus - fold of connecting vaginal tunic between the mesorchium and ductus deferens.
• • Mesofuniculus – part of the mesorchium between the parietal vaginal tunic and where the mesoductus arises.
• • Vaginal cavity – the potential space between the two vaginal tunic layers. It is continuous with a peritoneal cavity at the vaginal ring.