Life 49- Gas Exchange Flashcards
Trachea
A tube that carries air to the bronchi of the lungs of vertebrates. When plural, refers to the major airways of insects.
Tidal volume
The amount of air that is exchanged during each breath when a person is at rest
Inspiratory reserve volume
The amount of air that can be inhaled above the normal ideal inspiration
Alveolus
A small, baglike cavity, especially the blind saves of the lung
Intercostal muscles
Muscles between the ribs that can augment breathing movements by elevating and suppressing the rib cage.
Thoracic cavity
The portion of the mammalian body cavity bounded by the ribs, shoulders, and diaphragm. Contains the heart and the lungs.
Surfactant
A substance that decreases the surface tension of a liquid. In the lung, it is secreted by cells of the alveoli, is mostly phospholipid and decreases the amount of work necessary to inflate the lungs.
Expiration reserve volume
The amount of air that can be forcefully exhaled beyond the normal tidal expiration
Positive cooperativity
Occurs when a molecule can bind several ligand sand each one that binds alters the conformation of the molecule so that it can bind the next ligand more easily.
Bohr effect
The fact that low pH decreases the affinity of hemoglobin of oxygen.
Surface tension
The attractive intermolecular forces at the surface of liquid; especially important in water.
Bronchus
The major airway(s) branching off the trachea into the vertebrate lung.
Parabronchi
Passages in the lungs of birds through which air flows
Diaphragm
A sheet of muscle that separates the thoracic and abdominal cavities in mammals; responsible for breathing
Air sacs
Structures in the respiratory system of birds that receive inhaled air; they keep fresh air flowing unidirectional lay through the lungs, but are not themselves gas exchanged surfaces.
Dead space
The lung volume that fails to be ventilated with fresh air (because the lungs are never completely emptied during exhalation)
Respiratory gases
Oxygen and carbon dioxide; the gases that an animal must exchange between its internal body fluids and the outside medium (air or water)
Fick’s law of diffusion
An equation that describes the factors that determine the rate of diffusion of a molecule from an area of higher concentration to an area of lower concentration
Carotid body
A chemosensor in the carotid artery that senses a decrease in blood supply or a dramatic decrease in partial pressure of oxygen in the blood.
Hemoglobin
Oxygen-transporting protein found in the red blood cells of vertebrates (and found in some invertebrates)
External Gills
Highly branched and folded extensions of the body surface that provide a large surface area for gas exchange with water; typical of larval amphibians and many larval insects.
Countercurrent flow
An arrangement that promotes the maximum exchange of heat, or of a diffusible substance, between two fluids by having the fluids flow in opposite directions through parallel vessels close together.
Internal Gills
Gills enclosed in protective body cavities; typical of mollusks, Arthropods, and fishes
Lung
An internal organ specialised for respiratory gas exchange with air.
Vital capacity
The maximum capacity for air exchange in one breath; the sum of the tidal volume and the inspiratory and expiratory reserve volumes.
Pleural membrane
The membrane lining the outside of the lungs and the walls of the thoracic cavity
Bronchioles
The smallest airways in a vertebrate lung, branching of the bronchi.
