BIOL 199 Study Guide - Final Guide: Conjugate Acid, Reabsorption, Proximal Tubule
Organs of Excretion
• Waste must be excreted from the body to maintain homeostasis
o The urinary system releases a combination of water and other fluid made
up of urea, ammonia, and other chemicals
o Liver and large intestine filter bile pigment and dead red blood cells
o Skin releases sweat which contains water and electrolytes
o Lungs release CO2
Anatomy
• The urinary system has two kidneys which remove impurities (anything that
doesn’t belong or is in excess) and regulate water levels
• Two ureters drain fluid from the kidneys into the bladder
• The urethra releases urine from the body
Kidneys
• Kidneys have two distinct regions: the outer
cortex and the inner medulla
• Each kidney has many nephrons which filter
blood
o Kidneys have the ability to signal for
more red blood cells
Nephrons
• The glomerulus is a balled up blood vessel that
the nephron takes its blood from
• The renal tubule collects and filters the blood
o Bowman’s capsule – cup that squeezes
the blood out of the glomerulus
o Proximal tubule – closest to the capsule
o Loop of Henle – concentrated urine
o Distal tubule – closet to the collection
duct
• The same blood vessel twists around the tubule,
so good substances can diffuse back into the
blood
o Both the tubule and capillary are one
cell thick
o Water leaves the tubule throughout the
whole process
Function
• Kidneys are very important to homeostatic
maintenance
Document Summary
The urinary system has two kidneys which remove impurities (anything that doesn"t belong or is in excess) and regulate water levels. Two ureters drain fluid from the kidneys into the bladder. Kidneys: kidneys have two distinct regions: the outer cortex and the inner medulla, each kidney has many nephrons which filter blood, kidneys have the ability to signal for more red blood cells. The glomerulus is a balled up blood vessel that the nephron takes its blood from. The same blood vessel twists around the tubule, so good substances can diffuse back into the blood: both the tubule and capillary are one cell thick, water leaves the tubule throughout the whole process. Function: kidneys are very important to homeostatic maintenance. They keep water levels in check, remove waste, and maintain electrolyte and ph levels: high blood pressure is the result of not peeing enough. Blood filtration: filtration physical filtration process. Filtration salts go first, and water follows via.