2007-01-04 04:14:12 · 4 answers · asked by Gina I 1 in Science & Mathematics ➔ Biology
Humans have lung in which oxygen and CO2 are able to diffuse into and out of the bloodstream via alveoli. Fish use gills where the diffusion takes place by water passing over them.
2007-01-04 04:18:42 · answer #1 · answered by NML 1635 3 · 0⤊ 0⤋
Respiratory System Of Fishes
2016-12-10 18:29:55 · answer #2 · answered by ? 4 · 0⤊ 0⤋
In humans and other mammals, the respiratory system consists of the airways, the lungs, and the respiratory muscles that mediate the movement of air into and out of the body. Within the alveolar system of the lungs, molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous environment and the blood. Thus, the respiratory system facilitates oxygenation of the blood with a concomitant removal of carbon dioxide and other gaseous metabolic wastes from the circulation. The system also helps to maintain the acid-base balance of the body through the efficient removal of carbon dioxide from the blood.
Most fish exchange gases by using gills that are located on either side of the pharynx. Gills are made up of threadlike structures called filaments. Each filament contains a network of capillaries that allow a large surface area for the exchange of oxygen and carbon dioxide. Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gill filaments. The blood in the capillaries flows in the opposite direction to the water, causing counter current exchange. They then push the oxygen-poor water out through openings in the sides of the pharynx. Some fishes, like sharks and lampreys, possess multiple gill openings. However, most fishes have a single gill opening on each side of the body. This opening is hidden beneath a protective bony cover called an operculum. Some fishes, such as lungfish, have developed an adaptation known as a labyrinth that allows them to survive in oxygen-poor areas or places where bodies of water constantly dry up. These species of fish possess specialized organs that serve as lungs. A tube brings air containing oxygen to this organ by way of the fish's mouth. Some kinds of lungfish are so dependent on receiving oxygen from the air that they will suffocate if not allowed to reach the surface of the water.
2007-01-04 05:14:34 · answer #3 · answered by Saveena 1 · 0⤊ 0⤋
HUMANS HAV LUNGS AND FISHES HAV GILLS 4 RESPN!!!!!!!
2007-01-04 04:18:46 · answer #4 · answered by zak 1 · 0⤊ 0⤋