The human excretory system 1) excretes salts from its surface. a) liver b) lungs c) skin d) kidneys 2) responsible for excreting carbon dioxide. a) liver b) lungs c) skin d) kidneys 3) has functional units called nephrons. a) liver b) lungs c) skin d) kidneys 4) produces both urea & bile. a) liver b) lungs c) skin d) kidney 5) organ in which blood loses urea & reabsorbs glucose and amino acids. a) liver b) lungs c) skin d) kidneys 6) removes old red blood cells from the circulatory system. a) liver b) lungs c) skin d) kidneys 7) maintains homeostasis by removing body heat, water, & other wastes. a) liver b) lungs c) skin d) kidneys 8) adds or removes glucose from the blood as necessary. a) liver b) lungs c) skin d) kidneys which is the correct pathway for the elimination of urine? a) urethra, ureter, bladder, kidney b) kidneys, urethra, bladder, ureter c) bladder, ureters, kidney, urethra d) kidneys, ureters, bladder, urethra in humans, for carbon dioxide to be excreted, it must pass from the blood into: a) nephrons b) alveoli c) sweat glands d) the liver a blockage in a ureter would interfere with: a) urine entering the kidney b) urine entering the bladder c) urine leaving the body d) urea entering the kidney 12) which is not a metabolic waste in humans? a) carbon dioxide b) oxygen c) salt d) urea e) water