HOMEOSTASIS Flashcards
Functions of the Urinary System:
1) To excrete nitrogenous wastes such as urea and uric acid
2) To maintain the water-salt balance in the blood
3) To maintain the acid-base balance of blood
The kidneys are located on ___
either side of the spinal (vertebral
column) column, below the diaphragm!
urine is formed in the ___
kidney
Urine travels through ____to ____
Urine travels through the ureter to urinary
bladder
Urine is stored in the ____
urinary bladder until it is
ready to be released out the urethra.
In males, the urethra also carries sperm during
ejaculation.
- In females, the urinary and reproductive systems are
separate
Renal cortex
outer layer area
Renal medulla
contains cone-shaped renal pyramids
Renal pelvis
innermost hollow region where urine
collects before draining into ureter
The primary function of the kidneys is to produce ____
urine
each kidney is composed of ______
one
million tiny nephrons that actually produce the
urine.
Glomeruli capsule
blood is filtered and molecules from the blood inside the Glomerulus filter into the capsule
Glomerulus allow easy passage of molecules to diffuse Water, urea, glucose, amino acids, uric acids, and salts enters
Proximal convoluted tubule:
REABSORPTION
This tube is lined with cells that have many mitochondria and tightly packed microvilli
* The filtrate enters the proximal convoluted tubule.
* Reabsorption of filtrate occurs here. About 60 to 70% of nutrients, salt and water are reabsorbed here!
Nephron Loop:
helps with water reabsorption
Distal convoluted tubule:
helps begin the process of secretion
* Penicillin and H+ molecules are secreted into the urine
joins with the collecting duct .
Urine is made from water, urea, uric acid, salts, NH4+ and creatinine at this point
5) Collecting duct connects to deliver urine to renal pelvis, Urine is made up of
Urine is made from water, urea, uric acid, salts, NH4+ and creatinine at this point
Urine Formation
- Filtration
* Blood pressure forces small molecules from blood capillary into capsule—creates filtrate
* Water, nutrients, salts, and urea
* Next steps prevent loss of nutrients and water - Reabsorption of solutes
* Substances move back into blood, out of filtrate
* Selective process
* Numerous mitochondria for active transport
* Water follows as salt is reabsorbed - Secretion
* Moving substances into filtrate
* Uric acid, hydrogen ions, ammonia, and penicillin
* Helps get rid of harmful substances not filtered
- Filtration
- Blood pressure forces small molecules from blood capillary into capsule—creates filtrate
- Water, nutrients, salts, and urea
- Next steps prevent loss of nutrients and water
- Reabsorption of solutes
- Substances move back into blood, out of filtrate
- Selective process
- Numerous mitochondria for active transport
- Water follows as salt is reabsorbed
- Secretion
- Moving substances into filtrate
- Uric acid, hydrogen ions, ammonia, and penicillin
- Helps get rid of harmful substances not filtered
kidneys ___ bicarbonate ions and ____ hydrogen ions as
needed.
- If the blood is acidic, hydrogen ions are excreted and bicarbonate ions are reabsorbed.
- If the blood is basic, hydrogen ions are not excreted and bicarbonate ions are not reabsorbed.
reabsorb, excrete
____ buffers hydrogen ions in urine.
Ammonia (NH3)
Ammonia is produced in tubule cells by the breakdown of amino acids.
* Phosphate provides another means of buffering hydrogen ions in urine.
How to analyze a urine
sample?
- Color: dark = dehydrated
- Smell: sweet = indication of diabetes
- Cloudiness: more cloudy = higher risk of infection
High level of glucose in urine indicates
Glucose: High levels of glucose in the urine may mean diabetes
