Control & Coordination Part 1 The Respiratory System Year 9 Science 2013 Control & Coordination Part 1 The Respiratory System

Gas Exchange Oxygen and carbon dioxide need to be exchanged with the environment for ___________and _____________

Diffusion The process of gas exchange is always by _____________between the external and internal environment of the organism.

Surface Area: Volume For single-celled and small organisms this is not a problem because of their high ___________to __________ratio.

Multicellular Organisms Large organisms rely on specialised __________surfaces.

Features of Respiratory Surfaces Large____________ ______, _______and easily penetrable surface. Adequate____________ Efficient transport of carrier fluid_________) across respiratory surface.

Mammalian Respiratory System Is composed of: Lungs Respiratory passages ___________ ____________ _____________

Alveoli The site of________________ Increases the surface area for gas exchange. http://www.bmu.unimelb.edu.au/examples/gasxlung/

Breathing Contraction & relaxation of the __________muscle results in changes in pressure within the lung cavity, forcing air in & out.

Epiglottis The ___________prevents food from travelling down the trachea and blocking the passage of air.

Gas exchange relies on diffusion, therefore ______________gradients need to be maintained.

For oxygen to continually diffuse into capillaries around alveoli, oxygen needs to be transported ___________from the site

Respiratory pigments such as ___________carry oxygen in the blood from lungs and release oxygen into cells.

Rhythmic pumping of the __________ensures continuous flow of blood along capillaries surrounding the alveoli.

Haemoglobin and _____________bind in a reversible reaction.