Renal anat 3 - blood vess. anat of renal pelvis, ureters & bladder

Question 1

What is the main arterial supply to the kidney?

Answer 1

Renal arteries

• receive approx 25% of cardiac output.

Question 2

What does the renal artery branch into when it enters the hilum?

Answer 2

interlobar arteries (biggest arteries, NOT interlobular arteries)

• run between the lobes (= renal pyramids)
• then branches into the arcuate arteries

Question 3

What arteries branch from the arcuate arteries in the kidney?

Answer 3

interlobar arteries –> arcuate arteries –> interlobular arteries

• interlobular arteries –> smaller arteries which go to the renal corpuscles*
• give of afferent arterioles –> supply cortical glomeruli (& some juxtamedullary glomeruli)

Question 4

Explain the afferent arteries (where does enter and provide)

Answer 4

afferent arteriole: enters Bowman’s capsule

• associated with juxtaglomerula apparatus (juxtaglomerula cells - sense blood pressure)
• thicker than efferent (less blood pressure)
• divides into capillary plexus of the glomerulus

Question 5

explain the efferent arteries (where does it leave/size of the arterioles)

Answer 5

afferent arteriole –> leaves Bowmans capsule through the efferent arteriole

• efferent arteriole has smaller diameter (maintain high blood pressure for glomerular filtration)

Question 6

Name the two different courses of the efferent arterioles?

Answer 6

1) cortical glomeruli (nephron)

2) juxtamedullary glomeruli

Question 7

Describe the cortical glomeruli (nephron) capillaries that divide from the efferent arterioles?

Answer 7

efferent arterioles –> peritubular capillaries

• surround PCT, DCT & short loop of henle

Question 8

what is cortical nephron important for?

Answer 8

• reabsorption of H2O and salts*

Question 9

describe route of the efferent arterioles in the juxtamedullary glomeruli (nephron)?

Answer 9

efferent arterioles –> peritubular capillaries (like cortical nephrons)

• enter medulla –> branch into vasa recta (straight vessels)

–> associated with descending and ascending loops of henle

Question 10

what do the vasa recta vessels assist with in the medulla?

Answer 10

help set up of high osmalarity in the medulla -> helps with controlling hydration/concentration

Question 11

Describe the venous return that follows the arterial supply of the kidney (order)

Answer 11

Peritubular capillaries of cortex drain via interlobular veins –> arcuate veins –> interloba veins –> renal vein

• vasa recta drains to arcuate vein
• stellate veins –> superficial area of cortex may drain into these (prominent in cat forming capsular veins)

Question 12

what are the 3 layers of the renal pelvis wall?

Answer 12

tunica mucosa (transitional epithelium*)

tunica muscularis

tunica adventitia

Question 13

characteristics of the transitional epithelium for the urinary system

Answer 13

unique to urinary system –> tough and stretchy

–> urine pH can be tough so has to withstand this, and must be stretchy as bladder gets big/small

Question 14

Renal pelvis of dog, cat, sheep and goat (all the same) - remember what kidney structure they have.

Answer 14

Crest kidney

• expanded renal pelvis with several renal recesses extending up between pseudopappilae

Question 15

Renal pelvis of the pig (remember kidney type)

Answer 15

multipapilate kidney (individual papillae)

central renal pelvis and 2 major calices

several minor calices stem from these

Question 16

Renal pelvis of the horse (remember kidney type)

Answer 16

Terminal recess kidney

–> smaller crest and small renal pelvis with two long terminal recesses –> same epithelium as collecting ducts thus ‘fusion of collecting ducts’

Question 17

Renal pelvis of cow? (remember kidney type)

Answer 17

Renulate kidney

• no true renal pelvis –> just two branches into the ureter

–>ureter branches into 2 major calices –> branch into minor calices

Question 18

Describe the ureter

Answer 18

Muscular tube –> urine travels down the ureters into the bladder

• urine is propelled by peristaltic waves (like food)

Question 19

3 layers of the ureter:

Answer 19

1. tunica mucosae
2. tunica muscularis
   - inner longitudinal layer
   - circular layer
   - outer longitudinal layer
3. tunica adventitia

Question 20

layers of the ureter: role of the inner longitudinal muscle layer with preventing reflux of urine:

Answer 20

Inner longitudinal muscle layer remains as ureter tunnel through bladder –> allows ureter lumen to collapse with hydrostatic (fuid) pressure -> prevents reflux (urine going back up)

Question 21

Describe the bladder structure:

Answer 21

highly distensible (extended/dilated etc.)

encased by serosa continuous with peritoneum

serosal folds form ‘ligaments’

• lateral vesicular folds/lateral lig
• median vesicular folds/median lig

Question 22

What is the muscle in the bladder that controls urination?

Answer 22

Detrusor muscle

• 3 layers of s-shaped smooth muscle bundles surround bladder
• responsible for conscious/unconscious control of urine
• bladder innervation controlled by sympathetic and parasympathetic control

Question 23

Explain the male urethra structure: why does this effect urinary blocks in males?

Answer 23

Long and narrow*

shared with repro system

blocked urethra very common in male cats because of how narrow it is.

Question 24

female urethra structure: how does this effect urinary blocks in females?

Answer 24

Wider and shorter than males –> not shared with repro system

• less problems with obstruction (wider and shorter)
• easier for migration of bacteria though –> cystitis