urinary

• upper urinary tract


  kidneys

  ureters
• lower urinary tract 


  bladder

  urethra
• 
  

  1: hilum

  2: renal pelvis

  3:major calyx

  4: minor calyx

  5: renal capsule

  6: cortex

  7: medulla

  8: papilla

  9: renal lobe

  
• cow renal lobes


  multipyramidal (18-25 lobes)
• human and pig renal lobes

  cortex is fused but medulla is not (multipyramidal internally)
• dog horse sheep renal lobes

  unipyramidal - cortex and medulla are fuses. Forms a common renal crest which may be ridged
• cats renal lobes


  unipyramidal - complet fusion
• renal blood supply


  the peritubular artery branches into the afferent arteriole which branches into the glomerus, the first of two renal capillary beds. The glomerulus then branches into the efferent arteriole which branches into the second renal capillary bed, the peritubular capillaries. The peritubular capillaries surround the renal tubules. The peritubular capillaries then then empty into the venous system (interlobular vein, arculate vein, renal vein)
• the renal artery is a branch of the

  abdominal aorta
• hilus


  where blood vessels, nerves and ureters enter and leave the kidney
• glomerulus 


  cluster of capillaries
• the glomerulus is supplied from blood from the 


  afferent arteriole
• capsule


  protective layer os irregular dense connective tissue. Covers the whole kidney
• where does filtration happen

  Bowmans capsule
• what type of capillaries are in the glomerulus

  fenestrated capillary s
• renal corpuscle 


  glomerulus + Bowmans capsule
• what are podocytes


  they are specialised cells. They filtrate small molecules from blood plasma in the glomerulus and form an ultra filtrate of plasma
• what epithelium is the proximal convoluted tubule lined with

  simple cuboidal or columnar epithelium
• what does the proximal convoluted tubule reabsorb

  sodium, water, glucose, amino acids, potassium , urea, phosphate, citrate
• what epithelium is the loop of Henle lined with

  simple squamous epithelium
• distal convoluted tubule


  absorbs the things we didn't want to loose in the first place. Mainly absorbs water and waste products - takes waste products to collecting ducts
• what epithelium are the collecting ducts lined with

  columnar epithelium
• collecting ducts


  collect and drain urine
• loop on henle 


  descending part: highly permeable to water

  ascending part: not permeable to water
• RAAS system (1)


  decreased BP - decreased blood flow to the kidney - to enough sodium in the body - detected by the afferent arterioles - renin is released by the juxtaglomerular cells of the kidney - Reni converted angiotensinogen to angiotensin I - angiotensin ! is converted to angiotensin II by ACE in the lungs - angiotensin II controls blood vessels and increases peripheral resistance - increases BP - stimulated adrenal glands to release aldosterone -aldosterone promotes reabsorption - increased water retention and expansion of blood volume - increases BP
• RAAS system (2)

  angiotensin II works directly on blood vessels causing vasoconstriction which increases BP

  promoting aldosterone secretion from the adrenal cortex promotes reabsorption of water and sodium
• where do to the ureters enter the urinary bladder

  dorsal surface of the bladder at an oblique angle to prevent urine flowing back up the ureters
• what epithelium does the bladder have

  transitional epithelium
• what is unique about the renal blood supply

  there are two capillary beds: glomerulus and peritubular capillary. They are arranged in series to one another and separated by the efferent arteriole.
• how do the capillary beds relate to the function of the kidney

  The capillary beds are important for the kidneys to perform its functions of:

  excretion of metabolic waste products and chemicals

  regulations of water and electrolyte balance

  regulation of body fluid osmolality and electrolyte concentration

  the hydrostatic pressure is important for these functions. The high hydrostatic pressure in the glomerulus causes rapid fluid filtration while the lower hydrostatic pressure in the peritubular arteries permits rabbit fluid absorption.
• glomerular filtration rate


  the rate of two kidneys from the ultra filtrate (ml/min)
• renal clearance 


  the volume of plasma completely cleared of a given substance in ne minute
• ureters


  carry urine from kidney to bladder
• urethra


  carries urine from the bladder
• urethral peristalsis


  urethral peristalsis is the involuntary contraction and relaxation of muscles that propels urine down the ureters into the bladder
• trigone of bladder


  trigone of bladder is a triangular region os smooth mucosa on the caudodorsal surface of the bladder

  cranial: ureterovesivular junctions

  caudal: internal urethral sphincter
• relationship of ureter to other abdominal organs

  travels from abdomen to pelvic cavity

  inserts into genital fold, broad ligament

  sits underneath the colon

  oblique insertion, prevents urine reflux
• relationship of bladder to other abdominal organs

  position varies with filling

  in females: ovaries, uterus and vagina are dorsal to the bladder

  in males: defferent ducts and vascular glands are dorsal to the bladder

  may contact rectum
• relationship of urethra to other abdominal organs

  female: runs beneath the reproductive tract and opens at the vestibule

  males: extends to penis, embedded in tissue, associated with the rectum
• ureterovesicular junction


  it is where the ureters penetrate the baldder at an oblique angle. As pressure if the bladder rises due to the volume of urine the ureters are compressed shut. This prevents urine reflux which decreases the risk of kidney infections