Gas Exchange Revision Carousel Flashcards
Describe the mechanisms of inspiration.
-Diaphragm contract (moves down and flattens)
-External intercostal muscles contract to push rib cage up and out
-Volume of thorax increases
-Pressure decreases below atmospheric pressure
-Air rushes into lungs down a pressure gradient
Describe the roles of smooth muscle and elastic tissue in the airways.
SM-contracts to constrict airways
ET-Elongate smooth muscle again, recoiling the airway to its original shape and size
Describe the precautions that must be taken when using a spirometer.
-Subject should be free of asthma
-No air leaks in apparatus
-Sterilised mouthpiece
-Soda lime should be fresh and functioning
Describe what is meant by ‘vital capacity’ and state the factors that it depends upon.
Maximum volume of air that can be moved by the lungs in one breath and is measured by taking one deep breath and expiring all the possible air from lungs
-Dependent on
-Height
-Age/gender
-Exercise levels
Most bony fish have 5 pairs of gills covered by a bony flap, known as the …? What is the function of this bony flap?
Operculum which protects the gills and ensures a constant flow of water
Describe the structure of gills in bony fish.
-2 rows of gill filaments
-GF are slender branches of tissues known as primary lamellae and are attached to a bony arch
-Each gill filament is folded into secondary lamellae providing a vary large SA
Describe ventilation in bony fish.
Buccal cavity can change volume, floor of mouth moves downwards, drawing water into the buccal cavity, mouth closes and water is pushed through the gills. As water is pushed through, the opperculum moves outwards
How does air enter the tracheal system in an insect?
Spiracle
How is air supplied to respiring tissues in an insect?
Tracheal System
The ends of tracheoles in insects are filled with tracheal fluid. What is the function of this fluid?
Gaseous exchange occurs between air in tracheole and the tracheal fluid
When an insect is active, what changes occur in the insect to increase their oxygen supply?
Tracheal fluid can be withdrawn into the body fluid to increase the surface areas of the tracheole walls exposed to air
Describe what is meant by ‘tidal volume’ and state a typical figure.
Volume of air moved in and out with each breathe at rest (0.5dm3)
Describe 3 feature of an effective transport system.
-A fluid to carry oxygen and some nutrients around the body
-Exchange surfaces
-A pump to create pressure to push the fluid around the body
State the equation for ventilation rate.
Tidal Volume x Breathing Rate
Describe what is meant by ‘inspiratory reserve volume’.
Maximum volume of air you can breath in forcibly
