Anatomy and Physiology Exam 4
Urinary system
★ The kidneys
1. Main functions
a. Ridding body of waste materials that are ingested or produced
by metabolism
b. Controlling volume and electrolyte composition of body fluids
2. Regulatory function → maintains the stable internal environment
necessary for the cells to perform their various activities
a. Excretion of metabolic waste products, foreign chemicals, drugs,
hormone metabolites
■ Waste products must be eliminated from the body as
rapidly as they are produced
■ Urea, creatine, uric acid, end products of hemoglobin
breakdown, metabolites of hormones
b. Regulation of acid-base balance
■ Excrete acids and regulate the body fluid buffer stores
c. Regulation of water and electrolyte balances
■ Excretion must precisely match intake
■ Intake regulated by individuals eating and drinking
kidneys adjust their excretion rates
d. Regulation of arterial pressure
■ Dominant role in long-term regulation → excrete sodium
and water
■ Contribute to short-term regulation
e. Regulation of erythrocyte production
■ Secrete erythropoietin → stimulates production of RBCs
by hematopoietic stem cells in the bone marrow
f. Regulation of calcitriol
g. Gluconeogenesis → glucose synthesis
● Kidneys are positioned posteriorly
● CLINICAL → kidney trauma
○ Upper parts of both kidneys are protected by the thoracic cage
Urinary system
★ The kidneys
1. Main functions
a. Ridding body of waste materials that are ingested or produced
by metabolism
b. Controlling volume and electrolyte composition of body fluids
2. Regulatory function → maintains the stable internal environment
necessary for the cells to perform their various activities
a. Excretion of metabolic waste products, foreign chemicals, drugs,
hormone metabolites
■ Waste products must be eliminated from the body as
rapidly as they are produced
■ Urea, creatine, uric acid, end products of hemoglobin
breakdown, metabolites of hormones
b. Regulation of acid-base balance
■ Excrete acids and regulate the body fluid buffer stores
c. Regulation of water and electrolyte balances
■ Excretion must precisely match intake
■ Intake regulated by individuals eating and drinking
kidneys adjust their excretion rates
d. Regulation of arterial pressure
■ Dominant role in long-term regulation → excrete sodium
and water
■ Contribute to short-term regulation
e. Regulation of erythrocyte production
■ Secrete erythropoietin → stimulates production of RBCs
by hematopoietic stem cells in the bone marrow
f. Regulation of calcitriol
g. Gluconeogenesis → glucose synthesis
● Kidneys are positioned posteriorly
● CLINICAL → kidney trauma
○ Upper parts of both kidneys are protected by the thoracic cage
