Respiration & Breathing

Respiration

What is respiration?

It is the release of energy from food

substances in living cells.

respirationSugar is oxidised to release energy, carbon

dioxide and water are formed.Equation: sugar + oxygen energy + carbon dioxide + water

(i) sugar comes from food(ii) oxygen comes from air(iii) carbon dioxide is excreted thru’ lungs(iv) energy is used for life processes or lost

as heat (keeps body warm).

Breathing system

To move air in and out of lungs for gaseous exchange.

Gaseous exchange

Diffusion of oxygen from lungs into blood.

Movement of carbon dioxide from blood into lungs.

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Breathing System - Nasal Passage

nasal cavity

voice box

windpipe

epiglottis

Path taken by air to lungs.

1 Air passes through nasal passages, wind pipes and alveoli.

2 Wind pipes are kept open by cartilage rings.

3 Gaseous exchange takes place in alveoli.

Air Sacs - Alveoli

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The Rib cage

How air enters and leaves the lungs

Breathing

1 Chest expands to inhale

2 Chest contracts to exhale

Is breathing voluntary?

Inhalation

Exhalation

The Rib Cage The Bell jar

Compare and Contrast

Composition of air in the lungs

Gas Percentage ininhaled air

Percentage inexhaled air

Oxygen 21% 16%

Carbon dioxide 0.04% 4%

Nitrogen 79% 79%

Water vapour a little a lot

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Experiment to show that exhaled air contains

Carbon Dioxide

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Indicator used to test for presence of Carbon Dioxide

calcium hydroxide (lime water)

To test for presence of Carbon dioxide in Expired air

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Gaseous exchange in alveoli

Pulmonary Circulation

Respiratory System

Air Sacs

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Gaseous Exchange

Respiratory System

Return

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Exercise- Breathing Hard

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Recovery period

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What is energy needed for?

• Animals - for movement, sending messagesthrough nerves, transport of food, keeping warm.

• Plants - for taking up minerals from soil, openingand closing of stomata, and transport of food.

• All organisms - for growth, cell division, andmoving molecules against a concentration gradient

Energy

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Respiration in animal and plant

Gills of fish Fish breathe with gills.

Gills are feather-like structures with a rich supply of blood vessels.

Gills are found under the gill covers of fish.

Gillcover

Water entersthe mouth of the fish …

How a fish breathes in …How a fish breathes in …

Water entersthe mouth of the fish …

… and flows over the gills.

Oxygen passes through the walls of the blood vessels and into the blood.

How a fish breathes in …How a fish breathes in …

Gills

Carbon dioxide passesthrough the wallsof the blood vesselsand dissolves in the water.

How a fish breathes out …How a fish breathes out …

Water with dissolved carbon dioxide flows out from under the gill cover.

Carbon dioxide passesthrough the wallsof the blood vesselsand dissolves in the water.

How a fish breathes out …How a fish breathes out …

… through special nostrils called blowholes on top of their heads.

Dolphins and whales breathe …

blowhole

blowhole

How do different animals breathe? Lungs eg. Man, whale, seal, bat, snake, dog, cow Moist skin eg. Frogs, toads, salamander, earthworm Gills eg. Fish, tadpole, mudskipper Breathing tube eg. Wriggler, water stick insect Breathing holes eg. Ant, dragonfly

My Pals are Here! Science 4B © 2003 Times Media Private Limited

Respiratory System in Plants

underside of a leafstoma

• Plants exchange gases with their surroundings through the stoma.

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At nightAt night

oxygen

carbon dioxide

During respiration

oxygencarbon dioxide

During photosynthesis

oxygen

carbon dioxide

During respiration

In the dayIn the day

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Which is faster?What does it depend on?

Respiration and Photosynthesis