Module 3 Definitions Flashcards
Exchange surface
A specialised area adapted to make it easier for molecules to cross from one side of the surface to the other
Gaseous exchange
The movement of gases by diffusion between an organism an its environment across a barrier e.g. the alveoli
Tissue
A group of similar, specialised cells working together to perform a common function
Tidal volume
The volume of air moved in and out of the lungs with each breath at rest
Vital capacity
The largest volume of air that can be moved in and out of the lungs in one breath
Residual volume
The volume of air that always remains in the lungs even after the biggest possible exhalation
Inspiratory reserve volume
The volume of air that can be breathed in above the normal tidal volume
Expiratory reserve volume
The volume of air that can be breathed out above the normal tidal volume
Transport
The movement of oxygen, nutrients, hormones, waste and heat around the body
Open circulatory system
Blood does not always remain in vessels
Closed circulatory system
The blood always remains in vessels
Single circulatory system
Blood passes through the heart once for each circuit of the body
Double circulatory system
Blood flows through the heart for one circuit of the body. Contains a pulmonary circuit and a systemic circuit
Cardiac cycle
The sequence of events in one heartbeat
Myogenic
Muscle tissue that generates its own contractions
Fibrillation
The chambers of the heart contracting out of rhythm
Endothelium
Tissue that lines the inside of a structure e.g. a blood vessel
Partial pressure
The amount of pressure exerted by a gas relative to the total pressure exerted by all the gases in the mixture
Dissociation
The breakdown of a molecule into 2 molecules e.g. oxyhaemoglobin into oxygen and haemoglobin
The Bohr effect
The change in shape of the oxyhaemoglobin dissociation curve when carbon dioxide is present. Carbon dioxide causes oxyhaemoglobin to release more readily.
Transpiration
The loss of water by evaporation out of the leaves via the stomata
Xerophyte
A plant that is adapted to reduce water loss by transpiration so that it can survive in very dry conditions
Translocation
The transport of assimilates between the sources and sinks of a plant in the phloem tissue. This requires energy
Source
Where sucrose and other assimilates are loaded into the phloem e.g. leaf
Sink
Where sucrose and other assimilates are unloaded from the phloem e.g. flower
Assimilates
Carbon containing compounds produced by a plant using the carbon from carbon dioxide
