Question

Compare the functioning of alveoli in lungs and nephrons in the kidneys with respect to their structure and functioning.

Answer 1

	ALVEOLI IN LUNGS	NEPHRONS IN KIDNEY
STRUCTURE	Alveoli are small with a diameter of 0.1 - 0.2 mm.	A nephron is about 3 cm long and is 20-30 nm in diameter. Nephron is a cluster of thin walled blood capillaries.
FUNCTIONING	Alveoli provide a large surface area for exchange of gases in lungs. They absorb oxygen that is inhaled and diffuse it into the blood and pick up carbon dioxide from the alveoli and diffuse it into the lungs which is then exhaled out.	They filter the blood and maintain osmoregulation. They filter out urine from the blood by process of ultrafiltration, reabsorption, secretion and osmosis.