macroscopic anatomy of the urinary tract Flashcards
where are the kidneys located
- paired organs
- lie retro-peritoneally
- positioned in the dorsal abdomen
- positioned in the ventral lumbar region with limited mobility (except cat)
- right is most cranial (except in pig) lies in small fossa of the caudate liver lobe
- left kidney is most mobile
outline the anatomical landmarks of the left kidney
- cranial pole contacts the greater curvature of the stomach
- dorsomedial aspect of the cranial pole contacts the spleen laterally
- often the spleen is located ventral to the kidney making a useful acoustic window
- cranially the left kidney may contact the left limb of the pancreas
- medially the cranial pole contacts the left adrenal gland
- caudally there is small intestine and descending colon
- the ovary if present is located caudally and ventrally
outline the anatomical landmarks of the right kidney
- cranial pole is located within the renal fossa of the caudate lobe of the liver
- medially is the caudal vena cava
- dorsolateral to the caudal vena cava close to the medial aspect of the right kidney is the right adrenal gland
- ventrally is the descending duodenum
- ventrally and medially is the right pancreatic limb
- the ovary if present is caudoventral to the right kidney
how do you visualise the kidneys surgically
- retract mesocolon on left hand side to see left kidney
- retract mesoduodenum on right hands side to see right kidney
what are the basic components of the kidney
- outer fibrous capsule
- renal cortex
- renal medulla
the kidney is described as bean shaped in which species
- dog
- cat
- sheep
- goat
describe the appearance of equine kidneys
- more triangular
- right described as heart shaped
- left described as pyramidal
how are porcine kidneys described
long and flat
describe the appearance of bovine kidneys
- oval and irregular in shape
- obvious lobules = reniculate
what is a unilobular kidney
kidney with only one renal lobe (functional unit = lobe = cortex and medulla that work together)
which species have unilobar kidneys
rodents and lagomorphs
describe the kidney of the cow
- seperate cortices
- seperate medullae
- multiple lobes/pyramids
- multiple renal papillae
- multiple calices
- no pelvis
- lobulated surface
describe the kidney of a pig
- fused cortex
- seperate medullae
- obvious pyramids
- multiple renal papillae
- multiple calices
- branched pelvis
- smooth surface
describe the internal appearance of the kidney in the dog, cat, sheep, and horse
- fused cortex
- fused medullae
- lobes still seen internally
- pyramids partially merged
- papillae merged to form renal crest
- no calices
- single pelvis
- smooth surface
compare the kidneys across species
what is the difference between a calice and a pelvis
- the urine drains from the tip of the pyramids
- cattle pigs and primates have seperate pyramids, then each has a funnel attached to collect the urine (mino calyx)
- 2-3 minor calices drain into a major calyx
- major calices drain directly into the ureter in cattle
- in pigs and primates the major calices drain into a space called the renal pelvis which then drains into the ureter
- in dogs, cats, sheep and horses the medullary cones are fused (renal crest) and they have n calices. renal crest then draines into the renal pelvis
where is the renal pelvis located in the dog
renal sinus
discuss how the renal pelvis differs between species
- large irregular structure with broad finger like processes called recesses in single lobe species
- in the horse there are only 2 recesses
- smaller irregular structure with short stems ending in a dilated regione called calyces in pigs and primates
- divided proximal ureter leading to multiple calyces in cattle (no pelvis)
discuss internal renal vasculature
- basic flow is from hilus to cortex then cortex to medulla
- drainage is from medulla back to cortex to join cortical venous drainage
- arterial and venous patterns the same for large intra-renal vessels
- intra renal portal system
- outflow via hilus
outline the renal blood flow circuit
- aorta
- renal artery
- interlobar artery
- arcuate artery
- inter-lobular artery
- afferent glomerular artery
- glomerulus
- efferent glomerular artery
- renal tubule plexus
- inter-lobular vein
- arcuate vein
- inter- lobar vein
- renal vein
- caudal vena cava
describe the microvascular anatomy from the glomeruli
cortical glomeruli: peritubular capillaries in the cortex
juxtamedullary glomeruli: peritubular capillaries in cortex (90%) OR vasa recta in the medulla (10%)
explain how blood flows in the juxtamedullary nephrons
- afferent arteriole firstly enters bowmans capsule the the efferent arteriole exits
- the efferent vessel splits and supplies the peritubular capillaries around the PCT and DCT the drains to veins in the cortex
- the vasa recta around the LoH then drains to the arcuate veins
discuss the walls of the ureter and bladder
made up of
- mucous membrane
- urothelium (transitional epithelium)
- apical cellular protection against urine due to tight junctions
- urothelial cells tolerate stretching as bladder
- lamina propria
- muscular layer
- adventitia