26: Urinary

The pelvic inlet is also known as the…

cranial pelvic aperture

The pelvic outlet is also known as the…

caudal pelvic outlet

What is located between the caudal and cranial pelvic apertures?

pelvic walls and pelvic cavity

What “structure” is located in the caudal pelvic cavity? What is this made up of?

“pelvic diaphragm”

levator ani and coccygeus mm.

Describe the location and attachment of the levator ani muscle.

located along the pelvic walls/cavity

medial-dorsal surface of pubic bone and symphysis to ventral sacrum and 1st and 2nd Cd vertebrae

Describe the location and attachment of the coccygeus muscle. 

located along the pelvic walls/cavity

lateral to the levator ani m.

ischiadic spine to Cd 2-4 vertebrae

What is the name of the space located between the sacrum and dorsal rectum? How many are there?

pararectal fossa

technically 2, separated by the mesorectum

What is the name of the space located between the ventral rectum and dorsal genital tract?

rectogenital pouch

What is the name of the space located between the ventral genital tract and the dorsal surface of the bladder?

vesicogenital pouch

What is the name of the space located between the ventral surface of the bladder and the pelvic symphysis?

pubovescical pouch

Describe the perineum, what it surrounds, and its border.

portion of the body wall that covers the caudal pelvic aperture

surrounds anus and terminal parts of the urogenital tract

pelvic diaphragm borders dorsally

What is the anogenital distance, and what is its clinical significance?

distance between anus and genitals

used for sexing kittens, shorter in a female

Define the perineal region, and the structures that it includes.

externally visible projection of the perineum on the skin

anus, vulva

Define the perineal body, the location in a female and in a male.

internal tissue located between the rectum and urogenital organs

M: between the anal canal and bulb of the penis

F: median fibromuscular mass between the anus and vulva

What is the main function of the kidneys?

filter blood to detoxify and rid the body of waste in the form of urine

What is the main function of the ureters?

transport urine from the kidneys to the bladder

What is the main function of the urinary bladder?

temporary storage of urine

What is the main function of the urethra?

to eliminate urine

Describe the location of the left kidney in a dog.

ventral to L2-L4 (more caudal than right kidney)

Describe the location of the right kidney in the dog.

ventral to L1-L3 and recessed into the caudate process of the caudate lobe of the liver (more cranial than left)

Describe the normal size of the right kidney in a dog.

3 times the length of L2 vertebral body

Describe the location and size of the kidneys in cats.

right kidney is cranial to the left

more mobile than in a dog

2.4-3 times the length of L2 vertebral body

In older cats, what is a common finding when looking at the kidneys?

may be shrunken

The kidneys are encapsulated by what tissue, particularly in large animals?

adipose capsule

The kidneys have a fibrous outer capsule made up of what tissue (particularly in small animals)?

DICCT (dense irregular collagenous connective tissue)

The fibrous outer capsule of the kidney attaches to what structure(s)?

renal vessels and renal pelvis

What is the name of the cavity located just inside the renal hilus?

renal sinus

What is the renal sinus? What does it surround, and what tissue fills it?

cavity located just inside the renal hilus

surrounds the renal pelvis

filled with white or yellow adipose tissue

What structure is responsible for funneling urine from the kidney into the ureter?

renal pelvis

Te renal pelvis is located within what structure? Describe its location.

within the renal sinus

mucosa of the ureter that expands into the kidney

What are pelvic recesses? What do they do?

diverticula (extensions) of the renal pelvis that extend into the renal parenchyma

help collect urine from deeper aspects of the kidney

What are diverticula?

extensions

What tissues make up the renal parenchyma?

cortex and medulla

What is the outermost portion of the kidney?

renal cortex

Describe the appearance of the renal cortex. What does it contain?

reddish-brown, granular appearance

renal corpuscles

What is the function of the renal corpuscles, and what do they contain?

structure that actually does the filtering and detoxifying

glomerulus, collecting tubules, bowman’s capsule

What is the deepest layer of the kidney?

renal medulla

The renal medulla contains what structure?

renal crest

Describe the shape, tissue type, and what structures make up the renal crest

longitudinal ridge projecting into the renal pelvis and collecting tubules

ridge is made of medullary tissue

renal pyramids fuse together to form 

The renal pyramid is part of what structure?

renal medulla

What structure is located at the apex of the renal pyramid, and what does it do?

papilla

fits into renal pelvis

The papillary foramina empties urine into what structure?

renal crest

Urine is made in what portion of the kidney?

cortex

Trace the flow of urine through the kidney.

cortex

renal pyramid

renal papilla

renal crest

renal pelvis

ureters

The renal lobe contains what structures? What is special about this in small/large animals?

renal pyramid and the adjacent cortical tissue

contains both cortex and medulla

small animal: fused

large animal: separate

What percentage of cardiac output is received by the renal arteries?

up to 25%

What structure acts as a separation between the renal pyramids?

interlobar aa.

The arcuate arteries are located where?

cortico-medullary junction

What is the cortico-medullary junction?

where the cortex and medulla meet

The interlobular arteries go into what structure?

cortex

Trace the blood flow into the kidney to the glomerulus.

renal aa. > interlobar aa. > arcuate aa. > interlobular aa. > afferent arterioles > glomerulus > efferent arterioles (away from glomerulus)

Trace the drainage of the kidney.

stellate vv. > interlobular vv. > arcuate vv. > interlobar vv. > renal vv.

What is the main difference in vasculature of a cat?

subcapsular veins

What type of pattern do the subcapsular veins form, and where do they converge in a cat?

3-4 veins that form an arborizing pattern

converge towards hilus and into renal vein

Trace the sympathetic innervation of the kidney.

lateral horn (thoracolumbar) > ventral root > spinal n. > communicating branch > sympathetic trunk > splanchnic n. > celiacomesenteric ganglion > kidneys or pelvic plexus > kidneys

Trace the parasympathetic innervation of the kidney.

craniosacral region > vagus nerve > vagosympathetic trunk > vagus nerve > dorsal vagal branch > celiacomesenteric ganglion > pelvic plexus (synapse mostly here) > kidney

The renal pelvis is the most proximal portion of what structure?

ureter

Trace the path and structures 

renal pelvis > courses over dorsal surface of bladder > enters bladder dorsally at an oblique angle

What is the mesoureter?

the mesentery that holds the ureter to the body wall

What is peristalsis, and what is its purpose?

peristaltic contractions of smooth muscle surrounding the ureters

moves urine to the bladder

What is the reason that the ureter courses dorsally and enters the bladder at an oblique angle?

expansion of the bladder slows the ureter flow into bladder

acts as an anatomical valve

Describe the shape of the lateral and medial borders of the kidney, and list the names of the cranial and caudal borders. 

convex lateral border

concave medial border

cranial and caudal poles

The neck of the bladder is caudally continuous with what structure?

urethra

What is the trigone?

the location of ureteral orifices and urethral orifice

located inside the bladder on the dorsal surface

What are the serosal attachments of the bladder?

lateral ligaments of the bladder (2)

median ligament of the bladder

What structures courses through the lateral ligaments of the bladder, and what do these ligaments attach? 

ureters

umbilical a./ round ligament of the bladder and ureter (in cranial fold)

bladder to walls of the pelvis laterally

What is the fetal urachus? In what structure is the remnant of this contained?

where urine flowed from fetus to umbilical cord in utero

median ligament of the bladder

The urinary bladder wall is made up of what structure? What is the main muscle here?

thick tunica muscularis

detrusor muscle

What does the detrusor muscle do, and system controls it?

contracts the urinary bladder

completely under ANS control

Describe the sympathetic and parasympathetic influence on the bladder.

PNS: expands bladder walls

SNS: stimulates bladder contraction

What main vessels supply the bladder?

branches of the vaginal/prostatic a. (caudal vesicle aa.)

CATS: branch of umbilical a. (cranial vesicle a.)

What nerve controls the internal urethral sphincter and the detrusor muscle? What nervous system is this?

hypogastric n.

SNS

What nerve provides somatic control to the urethralis muscle (external urethral sphincter)?

pudendal nerve

What nerve provides PNS control to the bladder? What segment of the spine does this signal come from?

pelvic nerve

sacral spine

The urethra what muscle? What control is this muscle under, and what is its function?

urethralis m.

somatic control

voluntary sphincter, helps maintain continence

In a bitch, where is the urethral tubercle located?

the vestibulovaginal junction

opens onto the floor of the vestibule

In a male, the external urethral orifice is located where?

tip of the penis

What is urolithiasis? What is the treatment?

formation of bladder stones

cystotomy

What is a cystotomy?

cut into the bladder to remove stones

A blocked cat usually has what underlying condition? What is the treatment for the first time, and what is the more chronic treatment?

Feline Lower Urinary tract Disease (FLUTD)

1st time: perineal urethrotomy

3rd time: perineal urethrostomy

What is a urethrotomy, and what is a urethrostomy?

tomy: open up perineum, open urethra and remove stone

stomy: remove “penis” so cat urinates directly externally

Incontinence is common in what scenarios? How do you diagnose it? What is the treatment?

older spayed females, particularly ones who were spayed young

less control of external urethral sphincter, tends to happen while sleeping

Dx of exclusion- be sure to rule out everything else first

PROIN

What is patent urachus?

when fetal urachus does not clamp off at birth, causes continuous urine leakage

What is antifreeze toxicity? What does it cause, and what is the treatment?

ingestion of ethylene glycol, has a sweet taste

creates crystals in kidneys, blocks nephrology function and flow of urine (necrosis from the inside out

kidneys shrivel and become pale

ever clear vodka blocks the enzyme that converts the ethylene glycol into crystals

What is an ectopic ureter?

ureter bypasses bladder and goes to urethra

congenital

usually occurs in young females

urinary leakage and incontinence

What are cystoliths?

bladder stones

What is uroabdomen?

urine in the abdomen

caused by trauma, bladder rupture

sometimes iatrogenic

What does iatrogenic mean?

caused by vet