excretory system Flashcards
What are the functions of the kidneys?
filters blood to:
remove waste
maintain water balance
maintain blood pH
eliminates urea
What are the functions of the urinary system?
filter blood and create urine as a waste by-product
What are the structures of the urinary system?
kidneys, ureters, bladder and urethra
What are the components of urine?
Water - 95%
Urea - 2%
Creatinine - 0.1%
Potassium - 0.6%
Sodium - 0.1%
Chloride - 0.6%
What is the process of making urea called?
demination (look at notes)
Where does that making of urea take place?
Liver
What are the three processes of urine formation?
Filteration
Reabsorption
Secretion
What is filteration?
movements of chemicals from Glomerulus to Bowmans Capsule due to pressure
What is reabsorption?
movement of materials back into the blood from the nephron
What is secretion?
movement of chemicals from the blood to the nephron
What is the role of the kidneys and excretory system in maintaining blood pH levels?
-pH control occurs in the Proximal and Distal Tubules
-Build up of H+ ions lower body/blood pH
-CO2 combines with water in the nephron cells to form carbonic acid which breaks down into bicarbonate ion and hydrogen. Bicarbonate ion enters the blood and hydrogen is excreted into the nephon
-H+ ions recombine with phosphate or ammonia ions and are excreted with filtrate from the nephron
What is the role of the kidneys and excretory system in regulation of water balance?
The kidneys can adjust the concentration of the urine to reflect the body’s water needs, conserving water if the body is dehydrated or making urine more dilute to expel excess water when necessary
What is the feedback system associated with ADH? (look at notes)
-Specialized nerve receptors called osmorecpetors are located in the hythothalamus to dectect changes in osmotic pressure
-Sweating or water loss = more ADH solution/blood = osmotic pressure results in water leaving osmorecptors (cells shrink)
-less urine and more concentrated urine
-it increases water reabsorption
What is the feeback system associated with aldosterone? (look at notes)
-low blood volume or low blood pressure detected
-signal sent to adrenal gland
-aldosterone released into blood and travels to kidneys
-less urine and less concentrated urine
-it increases water reabsorption
What is the role of nephrons?
they cleanse the blood and balance the constituents of the circulation.
What are the structures of nephrons?
-afferent arteriole
-glomerulus
-efferent arteriole
-peritubular capillaries (tubular capillaries)
-bowmans capsule
-proximal convoluted tubule (PCT)
-loop of henle
-distal convoluted tubule (PCT)
-collecting duct
-renal pelvis
What is the job of the afferent arteriole?
carries blood to the glomerulus
What is the job of the glomerulus?
a high pressure cappillary bed that is the site of filtration (materials filter into the Bowmans Capsule)
What is the job of the efferent arteriole?
carries filtered blood away from the glomerulus to the peritubular capillaries (tubular capillaries)
What are the peritubular capillaries (tubular capillaries)?
a network of small blood vessels that surround the tubules of the nephron
What is the job of the Bowmans capsule?
cup like structure that surrounds the glomerulus that helps the glomerulus to filter blood
What is the job of the PCT?
to reabsorb water and solutes like sodium
What is the job of the Loop of Henle?
reabsorb water and sodium chloride from the filtrate and carries the filtrate from the proximal tubule to the DCT
What is the job of the collecting duct?
a tube that carries urine from the nephrons to the renal pelvis
