what does the urinary system do?
filters nitrogenous waste from the blood.
helps regulate water, electrolyte and acid base balances
how does the urinary system filter waste?
kidneys filter blood in nephrons and secrete or reabsorb electrolytes under the direction of hormones
why does the urinary system filter?
maintain blood pressure
filtration of waste from the blood
what is the kidneys 5 main functions?
removal of waste
water balance (in and out)
salt balance (homeostasis of blood osmolarity)
long term blood pressure homeostasis
acid/base balance of blood
where are the kidneys in the body?
in the back under the 12th rib. held in place by fat
The retroperitoneum is an anatomical space located behind the abdominal or peritoneal cavity
what are the main components of the urinary system?
kidneys,
ureters,
bladder,
prostate (in males)
urethra (longer in males)
what does the kidneys produce?
enzymes to help regulate blood pressure
hormone erythropoietin to simulate red blood cell production in bone marrow
what artery supplies the kidney with blood?
renal artery
what is the nephron?
functional unit of the kidneys:
the filter that forms urine.
each kidney contains over a million of these tiny filter
thousands of collecting ducts collects fluids from several nephrons and conveys it to the renal pelvis
what are the 3 main processes which result in urine formation?
glomerular filtration
tubular reabsorption
tubular secreation
what happens in glomerular filtration?
- blood enters the kidneys through the renal artery and flows into the glomerulus (network of tiny blood capillaries) locates within the bowmans capsule
- filtration pressure
the blood pressure in the glomerulus forces water, ions and small molecules out of the blood and into the bowmans capsule. - filtrate compostion
the substances that pass through the filtration membrane include: water, glucose, aminio acids, urea and electrolytes. protiens and blood cells are to large so remain in the bloodstream - formation of filtrate
the filterated fluid collects in the bowmans capsule and will eventually flow into the renal tubules.
what happens in tubular reabsorption?
location:
proximal convoluted tube
mechanisms:
passive diffusion, faciliated diffusion, active transport and osmosis
key substances are reabsorbed such as:
-water about 70%
-glucose and amino acids
-electrolytes (ions like sodium, potassium and bicarbonate)
what happens in tubular secreation?
mechanism
location
substances are actively transported from the blood into the renal tubules.- helps regulate the composition of urine.
location- distal convoluted tubule and collecting duct of the nephron.
substances secreated:
-urea
-creatinine
-drugs#
- potassium and hydrogen ions
mechanism
-active transport
what is nephrolithiasis?
kidney stones
a condition characteristed by the formation of solid mineral and salt deposits in the kidney
what are the symptoms of nephrolithiasis?
severe pain in the back, side or lower abdomen, (described as renal colic pain)- results from inflammation, stretching and spasms from the urinary tract.
- hematuria (blood in the urine)
-nausea and vomiting
-frequent urination or urgent need to urinate
-painful urination
what is the pathophysiology of nephrolithiasis?
what are the 3 factors which contribute
kidney storms form when there is an imbalance in the substances that make up urine:
-factors that contribute to stone formation:
-high concentration of calcium, oxalate or uric acid in urine.
- dehydration leading to concentrated urine
- certain metabolic disorders that affect how the body processes minerals
whats the diagnosis of kidney stones?
- medical history and physical examination
- imaging tests such as ultersound or ct
-urinalysis dipsticks to test for blood, crystals, infection (white cells, keytones, proteins and ph.
-blood in the urine usually indicates trauma to the urinary tract
what are the complications and management/ treatment of kidney stones?
UTI,
obstruction of urine flow,
kidney damage
dietary modifications,
increased fluid intake,
medical or surgical intervention to remove stones
high fluid intake for 24 hours to flush out the stone
what are the 4 types of kidney stones?
cystine stones
calcium stones
uric acid stones
stuvite stones
what are kidney stones risk factors
male,
family history,
dehydration
calcium supplements,
diet high in animal protiens,
hypothyroidism,
obesity.
what is the process of kidney stones being produced?
- supersaturation of urine:
- kidney stones begin to form when urine becomes supersaturated with certain substances (calcium, oxalate, uric acid and phosphate) - nucleation-
supersaturated urine can lead to formation of tiny crystals. nucleation. - crystal growth
ones formed they grow larger as more of the supersaturated deposit on them. - aggregation
the crystals can stick together forming larger aggregates. this happens by the presence of protiens and substances that promote or inhibate stone fornation - retention
if they become large enough they might not pass through the urinary tract and become lodged in the kidneys, ureters or bladder.
factors infulencing stone formation:
dehydration,
diet- high instake of salt, animal protien and oxaltee rich foods.
metabolic disorders- hyperparathyroidism, UTI
-genetics
what is renal failure?
when kidneys unable to remove bodys metabolic waste.
unable to perform regulatory functions.
Impaired renal excretion results in accumulation of waste and toxins in body fluids
Leads to disruption in endocrine and metabolic function, fluid, electrolyte and acid-base disturbances
what is chronic kidney disease?
a decrease in kidney function or damage to the kidneys lasting for 3 months or more. it is often classified into five stages based on the glomerular filtration rate, which measures how well the kidneys are filtering blood
