chapter 46~ respiratory system Flashcards
The environmental source of O2 and the “sink” for released Co2. For aquatic animals, the respiratory medium is water; for terrestrial animals, it is air.
Respiratory medium
The process by which animals exchange gases with their surroundings — how they take in oxygen from the outside environment and deliver it to body cells, and remove carbon dioxide from body cells and deliver it to the environment.
External respiration
A layer of epithelial cells that provides the interface between the body and the respiratory medium.
Respiratory surface
A branching network of tubes that carries air from small openings in the exoskeleton of an insect to tissues throughout its body.
Tracheal system
The organ system responsible for gas exchange, consisting of all parts of the body involved in exchanging air between the external environment and the blood.
Respiratory system
A respiratory organ formed as evagination of the body that extends outward into the respiratory medium.
Gills
One of a pair of invaginated respiratory surfaces, buried in the body interior where they are less susceptible to drying out; the organs of respiration in mammals, birds, reptiles, and most amphibians.
Lungs
The flow of blood or other body fluids on the internal side of the respiratory surface.
Perfusion
The flow of the respiratory medium (air or water, depending on the animal) over the respiratory surface.
Ventilation
The exchange of gases with the respiratory medium by animals.
Breathing
A mechanism in which the water flowing over the gills moves in a direction opposite to the flow of blood under the respiratory surface.
Countercurrent exchange
A gill extends out from the body and contacts the water directly. An external gill lacks a protective covering.
External gills
A gill located within the body that has a cover providing physical protection for the gills. Water must be brought to…
Internal gills
In insects, an extensively branched, air conducting tube formed by invagination of the outer epidermis of the animal, and reinforced by rings of chitin. In vertebrates, the windpipe, which branches into the bronchi.
Tracheae
An opening in the chitinous exoskeleton of an insect through which air enters and leaves the tracheal system.
Spiracles
In bird lungs, an array of fine, parallel tubes through which air flows, and across which a capillary network crosses in a perpendicular direction to produce a cross current pattern of blood flow relative to the air flow.
Parabronchi
One of the millions of tiny air pockets in mammalian lungs, each surrounded by dense capillary networks.
Alveoli
A gulping or swallowing motion that forces air into the lungs.
Positive pressure breathing
Muscular contractions that expand the lungs, lowering the pressure of the air in the lungs and causing air to be pulled inward.
Negative pressure breathing
One of the small, branching airways in the lungs that lead into the alveoli.
Bronchioles
The throat. In some invertebrates, a protrusible tube used to bring food into the mouth for passage to the gastrovascular cavity; in mammals, the common pathway for air entering the larynx and food entering the esophagus.
Pharynx
An airway that leads from the trachea to the lungs.
Bronchi
The voice box.
Larynx
The volume of air entering and leaving the lungs during inhalation and exhalation.
Tidal volume
