17. Urinary System (Incomplete)

What is the major function of the urinary system?

To remove chief excretory fluid (urine)

What is the major function of the genital organs?

Serve for the formation, development, and expulsion of the products reproductive glands

Why is it called the Urogenital system?

The common origin of elements of the two organ groups as well as the urinary and reproductive systems in the adult share the final portions that deliver their products to the exterior

What is the list of essential functions carried out by the urinary system?

Excretion of metabolic waste, regulation of fluid balance, electrolyte homeostasis, acid-base balance, blood pressure regulation, erythropoiesis regulation, vitamin D activation, filtration and reabsorption, and urine storage & elimination

What are the components of the urinary system?

Paired kidneys, ureters, bladder, and the urethra

What do the kidneys do?

Form the urine from the blood

What do the ureters do?

Convey the urine from the kidneys

What does the bladder do?

Stores the urine until it can be discharged conveniently

What does the urethra do?

Finally expels the urine to the exterior

Where is the right kidney located in a dog?

T13-L3

Where is the left kidney located within the dog?

L2-L4

Where is the right kidney located in a cat?

L1-L4

Where is the left kidney located in a cat?

L2-L5

Where is the right kidney located in a horse?

T15-L1

Where is the left kidney located in a horse?

L1-L3

Where is the right kidney located in ruminants?

T13-L3

Where is the left kidney located in ruminants?

Displaced to the right due to the rumen causing it to appear pendulous

Where are both kidneys located in pigs?

L1-L4

What is the shape of the kidneys in horses?

Right - heart shaped; left - bean shaped

How are the kidneys described in relation to one another in dogs & cats?

Right - more cranial and fixed; left - more mobile

What is the term for when kidneys overlap on a radiograph and there is a whiteish area as a result?

Summation

How are you able to tell that it is a bovine kidney?

Deep surface lobations

What is internal milieu?

Essentially interstitial fluid

What do the Juxtaglomerular complexes produce and release?

Renin

What does renin do?

Plays a vital role in the regulation of systemic blood pressure

What is labeled A?

Renal medulla

What is labeled B?

Renal pelvis

What is labeled C?

Renal cortex

What is labeled D?

Cranial extremity

What is labeled E?

Lateral border

What is labeled F?

Caudal extremity

What species has capsular veins?

Feline

Where are the capsular veins located?

Within the renal capsule

What is the role of the capsular veins?

Support venous drainage of the kidney

What are the major functions of the capsular veins?

Drain the renal capsule, provide collateral venous drainage, assist thermoregulation of superficial renal tissue, and help equalize cortical venous pressure

How do the capsular veins drain the renal capsule?

Collecting venous blood from the fibrous capsule and removing blood from superficial cortical tissues immediately beneath the capsule

What structures do the capsular veins anastomose with?

Cortical venous tributaries, ureteric veins, adrenal veins, and lumbar veins

What is the importance of the anastomoses of the capsular veins with the various structures?

Creation of alternate venous return pathways which is useful if the main renal vein drainage is partially compromised

How do the capsular veins assist in thermoregulation?

Regulation of heat exchange at the kidney’s surface as maintenance of optimal cortical microenvironment

How do the capsular veins help equalize cortical venous pressure?

By reducing localized venous congestion and stabilizing cortical perfusion

Why are the capsular veins important clinically?

May bleed during renal capsulotomy, can enlarge during renal inflammation, provide collateral pathways in renal vein obstruction, and are encountered when reflecting the capsule during dissection

What gives the right kidney a fixed location in most species?

Cranial extremity fitting into the renal fossa on the liver

What spinal region are the kidneys located in?

Lumbar

Within their region of the spine, how else are the kidneys described location wise?

Pressed against the abdominal roof on either side of the vertebral column

What cushions the kidney?

Fat

How is the surface of the kidney normally described?

Smoothly convex (aside from the renal sinus indent)

What are the divisions of the renal parenchyma?

Outer cortex and inner medulla

What limits the expansion of the kidney and encodes its parenchyma?

A tough fibrous capsule

How is the outer cortex described?

Reddish-brown and finely granular

How is the inner medulla described?

Dark, purplish outer zone with a paler, greyish-red and radially striated inner zone

What is the most common medullary arrangement?

Multipyramidal/multilobar

What are the medullary arrangement options?

Multipyramidal/multilobar or unipyramidal/unilobar

What constitutes a renal lobe in a multilobar arrangement?

Discrete masses each roughly pyramidal in form with a cortical cap at the base

Which way does the apex of the pyramid in a renal lobe point and what does it form?

Towards the renal sinus forming a papilla that fits into a cup like expansion of the renal pelvis

What is the renal artery a branch of?

Abdominal aorta

What vessel are the kidneys supplied by?

Renal artery

What does the renal artery divide into?

Interlobar arteries

What do interlobar arteries branch into?

Arcuate arteries

What structure do the arcuate arteries curve around?

Base of the pyramids

What do the arcuate arteries branch into?

Interlobular arteries

What do the interlobular arteries supply?

The units or lobules in the cortex that is divided by the medullar rays

How are the veins within the kidney described?

Broadly satellite

Provide the correct branching pattern of the blood supply to the kidney.

Abdominal aorta → renal artery → interlobar arteries → arcuate arteries → interlobular arteries