Download Chapter 6 Renal

Chapter 6
Renal System
Name and identify the basic structures in the renal system.
kidney - bean shaped organ that excretes waste products from the body; located in the
space between the peritoneum and the muscles adjacent to the spine
medulla - innermost part of the kidney
cortex - outer portion of the kidney renal artery - artery branching from the abdominal
aorta and supplying blood to the kidney
abdominal aorta - portion of aorta that extends through the abdominal cavity
renal vein - vein that returns blood from the kidney to the caudal vena cava
ureter - tubular structure that carries urine from the kidneys to the urinary bladder
bladder - a hollow organ that collects, stores, and releases urine
urethra - tube that carries urine from the bladder to the outside of the body (during
urination)
Name and explain the functions of the renal system.
1. Excretion of nitrogen containing waste
• proteins and amino acids breakdown and produce ammonia (nitrogen compound with
strong smell; extremely toxic to tissues)
• liver converts ammonia to urea (organic compound also containing nitrogen)
• nucleotides (form DNA & RNA) breakdown to uric acid (forms salts)
• muscle activity produces creatinine (chemical waste product)
2. Regulation of body compounds and serum pH (the level of acidity in blood serum)
• regulate sodium (Na), chloride (Cl), potassium (K), by conservation in times of need
(ELECTROLYTES!!!)
• when blood pH increases/decreases, kidneys excrete less/more hydrogen ions
3. Production of hormones
• controls blood pressure and RBC production
Identify structures within the kidney and detail the formation of urine and its
regulation
nephron - structural unit of kidney that produces urine; tubular structure that is closed at
one end and opens at the opposite
*Kidney filters blood through nephron - small molecules are forced through filtrate kidneys recapture useful molecules and return them to bloodstream
Glomerulus - a bundle of capillaries inside of the Bowman’s capsule. Blood is delivered
to capillaries and water is forced to Bowmans Capsule.
Bowmans Capsule - a folded section of the nephron that surrounds the glomerulus.
Large proteins are filtered out.
Proximal Convoluted Tubule - first section of tubular nephron. Reabsorption of essential
molecules takes place.
Loop of Henle - long thin loop of nephron. Sodium is pumped out.
Distal Convoluted Tubules - highly coiled tubules. More sodium is pumped out, blood
pH is regulated.
Collecting ducts - area where nephrons empty into. Collection of urine before drainage
into renal pelvis.
renal pelvis - innermost portion of kidney. Collects urine from ducts, moved to bladder
for storage.
Evaluate urine and blood as a measure of the health of the animal and urinary
system.
URINALYSIS - complete evaluation of urine; consists of 3 parts
1. Physical
a. Color - yellow of varying intensity depending on hydration
b. Clarity - clear vs. cloudy
c. Volume - how much is produced per micturition in mLs
d. Odor - None, fruity, ammonia, etc.
2. Chemical
a. Urine Test Strips - strips dipped into urine sample that change color to indicate
presence/absence of various items. (Table 6-2, pg 93)
b. Specific Gravity - weight of urine as compared to distilled water. Higher # = higher
concentration. Refractometer - instrument used to measure specific gravity.
3. Microscopic
a. Urine is centrifuged and the remaining sediment stained and viewed under
microscope.
b. Bacteria, blood cells, skin cells, and crystals can be viewed. (Figure 6-15, pg 96)
BLOOD TESTS
Blood chemistry profiles are offered in most clinics or samples can be sent to
commercial laboratories.
Tests are grouped together to measure various aspects of the blood. (Table 6-4,
pg 97)
Will include test result and normal reference range.
Urea & creatinine - compounds cleared from blood by kidney.
Na, K, Cl, Ca, PO4 - electrolytes; kidneys maintain normal blood levels
Discuss the clinical significance of chapter material.
Azotemia - elevation of blood urea nitrogen and creainine
Uremia - group of clinical signs associated with azotemia; include vomiting, diarrhea,
poor appetite, bad breath, lethargy
Acute renal failure - kidneys suddenly are unable to maintain normal function; often
toxin ingestion (antifreeze)
Chronic renal failure - kidneys lose ability to maintain normal function over a long period
Skin turgor - measure of how quickly the skin returns to normal position when pinched;
indicates dehydration levels (table 6-6, pg 98)
Replacement volume - amount of fluid treatment in ml that is given to dehydrated
animals.
Replacement volume (ml) = %dehydration x body weight (kg) x 1,000
Maintenance volume - amount of fluid treatment in ml the maintains hydration levels
Maintenance volume (ml) = 20-25ml/kg/day