excretory system Flashcards
what is the excretory system?
process which allows waste products to be removed
what does the excretory system consist of?
-kidneys
-bladder
-ureters
-urethra
in mammals:
what are ureters?
two tubes which carries urine from kidneys to the bladder
in mammals:
what does the bladder do?
stores urine before it is removed from the body
in mammals:
what does the urethra do?
allows passing of urine from bladder out of the body
in birds:
what are the ureters?
two tubes which carries urine from the kidneys to the cloaca
in birds:
what is the cloaca?
allows urine and other waste products to be cleared from the body
in birds:
How do they remove ammonia?
in the form of uric acid
-does not require water and is an insoluble substance
in mammals:
How do they remove ammonia?
in the form of urea
-requires water to allow it to be excreted as urine
what are the kidneys?
key organ involved in waste removal
what do kidneys contain?
millions of nephrons
what takes place in nephrons?
ultrafiltration of the blood and urine is produced
what happens with kidney failure?
a buildup of toxic products in body tissue
nephrons:
what is the glomerulus?
a knot of capillaries
nephrons:
what is the renal (bowman’s) capsule?
collects the filtrate from the glomerulus
nephrons:
what is the tubules?
allow transportation of filtrate to and from the loop of Henle
nephrons:
what does the collecting duct do?
collects urine and passes to the ureter
what three processes of the kidneys are nephrons at the site of?
1.ultrafiltration
2.selective reabsorption
3.urine formation
what is ultrafiltration?
removing substances from the blood
what is selective reabsorption?
reabsorbing the substances, the body needs
what is urine formation?
substances which are not reabsorbed travel as urine along nephron to the collecting ducts where the waste travels to the bladder
where does ultrafiltration occur?
in the renal (Bowman’s) capsule
what happens during ultrafiltration?
blood enters via the renal artery and flows through many capillaries under high pressure
what are three parts of the loop of Henle?
1.descending limb
2.ascending limb
3.distal convoluted tube
what is the descending limb?
(In the loop of Henle)
-it is permeable to water
-water leaves the nephron by osmosis and is reabsorbed
- as much water as the body needs is reabsorbed
what is the ascending limb?
(In the loop of Henle)
-this is permeable to ions
what is the distal convoluted tubule?
(In the loop of Henle)
-where final reabsorption of ions and water occurs
what is osmoregulation?
maintaining the balance of salt and water concentrations
what is the ornithine cycle?
it takes place in the liver, and it converts ammonia to urea
what are two excretory disorders?
-liver damage
-nephritis
what is cirrhosis?
when scar tissue affects normal liver function
common causes of cirrhosis are?
-damage to liver from disease, medication or toxins
-infection of hepatitis C
-excess fat build up in liver
are there any treatments for cirrhosis disease?
-there is no treatment
however,
-healthy diet
-exercise
can stop it from getting worse
what are the symptoms of cirrhosis?
-loss of appetite
-weight loss
-vomit and/or diarrhea
-lack of energy
-increase of urination
what is nephritis?
an inflammation of the kidneys
-causes problems with filtering blood
what is nephritis caused by?
disease
medications
some disorders
what are symptoms of nephritis?
-weight loss
-protein in urine
-increased urination
-increased vomit
-vomiting
