(12) URINARY SYSTEM OF THE DOG Flashcards
• Considered part of the urogenital system
Organs of the Urinary system
The urinary system consists of the following organs:
– Kidneys
– Ureters
– Urinary Bladder
– Urethra
• Functional organs of the urinary system that filters blood and produce urine
• Functions:
– Excretion of nitrogenous waste
– Vitamin D metabolism
– Recover proteins, sugars and water from the filtrate; plays an essential role in electrolyte balance and mineral conservation
– Produce vasoactive substances (agents that play a role in blood pressure regulation) and erythropoietin (a hormone that stimulates red blood cells
Kidneys
– Elongate, smooth-surfaced, dark reddish-brown and bean-shaped
– Lies along the dorsal abdominal wall to the right and left of the vertebral column, just ventral to the sublumbar muscles
Kidneys
right kidney lying more cranial than left kidney by about half the length of the organ
Staggered in position
This organ extends from T12 or T13 to L2 or L3; more firmly fixed than the left; but both are somewhat mobile
Right kidney
This organ extends from L2-L3
Left kidney
lies with its cranial pole embedded in the renal impression in the caudate process of the caudate lobe of the liver
Right kidney
Right kindey relation: liver and right adrenal gland
Cranially
Right kindey relation: caudal vena cava
Medially
Right kindey relation: descending duodenum, pancreas and full stomach
Ventrally
Right kindey relation: last rib and abdominal wall
Laterally
Right kindey relation: spleen and full stomach
Dorsally
lies about ½ a kidney length caudal to right kidney
Left kidney
Left kindey relation: spleen, pancreas and full stomach
Cranially
Left kindey relation: left adrenal gland and aorta
Medially
Left kindey relation: descending colon
Ventrally
Left kindey relation: spleen and abdominal wall
Laterally
Left kindey relation: spleen and full stomach
Dorsally
– an indentation/depression on the medial border of the kidney (in the same position as the “eye of the bean”)
• Structures that passes through are the following:
– Renal artery and vein
– Renal nerves
– Renal lymphatic vessels
– Ureter
Renal hilus
a thin, string connective tissue sheet intimately surrounds all external surface of the kidneys and extends inward through the hilus to line the walls of the renal sinus
Fibrous capsule
a cavity/space within the kidney
Renal sinus
structural and functional unit of the kidney
Nephron
composed of glomerulus (a capillary tuft) surrounded by glomerular (Bowman’s) capsule
Renal corpuscle
outer region of kidney ; consists of proximal and distal convoluted tubule,peritubular capillary network, renalcorpuscles
Cortex
inner region; comprised mainly of nephric loops, collecting ducts, and long looped capillaries
Medulla
consists of renal pyramid and its overlying cortical cap and the renal crest
Renal lobe
triangular portions of the medulla that are best appreciated on parasagittal sections
Renal pyramids
the area of the apex of each adjacent renal pyramid
Renal papilla
formed by fusion of the apices of adjacent renal pyramids
Renal crest
This system begins in the kidney and ends at the urinary bladder
Collecting system
the region on the renal crest where the papillary ducts open
Area cribrosa
dilated proximal portion of the ureter, within the renal sinus
Renal pelvis
• Description and location:
– Tubes of smooth muscles that carry urine from the kidney to the urinary bladder
– Retroperitoneal
Uretres
slightly longer than the left uretres
Right ureter
Ureters Course:
Caudally and slightly medially en route to the urinary bladder
courses in the ventral surface of the psoas muscles (lies ventral to the caudal vena cava and iliac arteries, but dorsal to the arteriessupplying the gonads
Abdominal part
( male or female ) ureter continues its slightly oblique course directly to the urinary bladder
Females
( male or female ) pass dorsal to ductus deferens, and each ductus deferens loops around its respective ureter en route to urethra
Males
blind, rounded cranial end, highly mobile part of the urinary bladder
Apex
main part, highly distensible, highly mobile part of the urinary bladder
Body
terminal portion of urinary bladder, where it narrows to join the urethra; fixed in its intrapelvic position, even when the bladder is maximally distended
Neck
– On the ventral surface of the urinary bladder and attaches to the abdominal wall as far cranial as the umbilicus
– Contains the urachus and the umbilical arteries in the fetus
Median ligament of the bladder
– this ligament of the urinary bladded passes to the pelvic wall
– Often contains an accumulation of fat along with the ureters and the umbilical artery
Lateral ligament of the bladder
A fetal structure (the allantoic stalk) that extends between the lumen of the urinary bladder and the umbilical cord
Urachus
a triangular region in the internal surface of the dorsal wall of the urinary bladder
Trigone
• A tubular organ that extends from the neck of the urinary bladder to the external body surface
Urethra
shorter and simpler in form because it functions only in the elimination of urine
Female urethra
Their urethra are divided into three regions
Male urethra
most proximal urethra of male, where the organ is surrounded by the prostate gland
Prostatic urethra
a low longitudinal ridge of tissue along the urethral dorsal midline
Urethral crest
a small, elliptical knob at approximately the midpoint of urethral crest
Colliculus seminalis
Urehtra of male that succeeds the prostatic part and extends as far caudally as the pelvic outlet
Pelvic urethra
Urehtra of male that extends from the pelvic outlet through the full length of the penis, to open to the exterior of the body at the distal tip of the glans penis
Penile urethra
