BREATHING WHICH IS NOT RESPIRATION

Transcription

1 BREATHING WHICH IS NOT RESPIRATION

2 Breathing vs. Respiration All animals respire. A lot of people think respiration means breathing- this is not true! Breathing is the physical process of inhaling oxygen and exhaling carbon dioxide Respiration is the chemical process of the body converting glucose and oxygen into energy. It occurs in all cells in our body. Not all animals breath in the same way plus plants need a way to exchange gases too!!

3 Respiration in animals Whether they live in water or on land, all animals must respire. To respire means to take in oxygen and give off carbon dioxide. Some animals rely of simple diffusion through their skin to respire. While others Have developed large complex organ systems for respiration.

4 Respiratory System Function: to provide oxygen gas need for cellular respiration and remove carbon dioxide from the body Invertebrate Organs: gills and trachae Main Vertebrate Organs: Nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, lungs, gills, diaphragm

5 Vertebrate respiratory systems Chordates have one of two basic structures for respiration: Gills for aquatic chordates Example: tunicates, fish and amphibians Lungs - for terrestrial chordates Examples: adult amphibians, reptiles, birds, and mammals

6 Mammals The chief organ in mammalian respiration is the lungs. Breathing is dependent upon the rib muscles and the diaphragm, a structure shaped like a dome-shaped floor just beneath the lungs.

7 Mammals Inhalation happens when the rib cage opens up and the diaphragm flattens and moves downward. The lungs expand into the larger space, causing the air pressure inside to decrease. The drop in air pressure inside the lung makes the outside air rush in. Exhalation is the opposite process. The diaphragm and the rib muscles relax to their neutral state, causing the lungs to contract. The squashing of the lungs increases their air pressure and forces the air to flow out.

8 Mammals Oxygen enters the body in the mouth and nose, passes through the larynx and the trachea. The trachea splits into two bronchial tubes, which lead to smaller tubes that lead to 600 million alveoli, which are small sacs surrounded by capillaries. The capillaries take oxygen into the arteries, and the oxygen-rich blood is then pumped into every cell of your body. Once the oxygen has been absorbed, carbon dioxide and water are eliminated through the lungs.

9 Section 37-3 Figure The Respiratory System The Human Respiratory System

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11 Fish Blood passing through the gills is pumped in the opposite direction to the water flowing over these structures to increase oxygen absorption efficiency. This also ensures that the blood oxygen level is always less than the surrounding water, to encourage diffusion The oxygen itself enters the blood because there is less concentration in the blood than in the water: it passes through the thin membranes and is picked up by hemoglobin in red blood cells, then transported throughout the fish s body.

12 Aquatic Gills Water flows through the mouth then over the gills where oxygen is removed Carbon dioxide and water are then pumped out through the operculum

13 Birds Respiration in birds is much different than in mammals. Birds have a larynx, but it is not used to make sounds. Birds have lungs, but they also have air sacs. Depending upon the species, the bird has seven or nine air sacs.

14 Birds The air sacs permit a unidirectional flow of air through the lungs. Unidirectional flow means that air moving through bird lungs is largely 'fresh' air & has a higher oxygen content.

15 Birds In contrast, air flow is 'bidirectional' in mammals, moving back and forth into and out of the lungs. As a result, air coming into a mammal's lungs is mixed with 'old' air (air that has been in the lungs for a while) & this 'mixed air' has less oxygen. So, in bird lungs, more oxygen is available to diffuse into the blood.

16 Birds Birds do not have a diaphragm; instead, air is moved in and out of the respiratory system through pressure changes in the air sacs.

17 Amphibians Most amphibians breathe with gills as larvae and with lungs as adults. Additional oxygen is absorbed through the skin in most species. The skin is kept moist by mucus, which is secreted by mucous glands. In some species, mucous glands also produce toxins, which help protect the amphibians from predators.

18 Reptiles The scales of reptiles prevent them from absorbing oxygen through their skin, as amphibians can. Reptiles breathe air only through their lungs. Their lungs are more efficient than the lungs of amphibians, with more surface area for gas exchange. This is another important reptile adaptation for life on land.

19 Reptiles Reptiles have various ways of moving air into and out of their lungs. Lizards and snakes use muscles of the chest wall for this purpose. These are the same muscles used for running, so lizards have to hold their breath when they run. Crocodiles and alligators have a large sheet of muscle below the lungs, called a diaphragm, that controls their breathing. This is a structure that is also found in mammals

20 Reptiles Gas exchange in reptiles still occurs in alveoli however, reptiles do not possess a diaphragm. Breathing occurs via a change in the volume of the body cavity which is controlled by contraction of muscles in all reptiles except turtles.

21 Vertebrate lungs As you move from amphibians to mammals the surface area of the lungs increases Insures a greater amount of gas exchange (or a two way flow of air). Birds, by contrast have lungs and air sacs which have only a one-way flow of air. This allows for them to have constant contact with fresh air. This adaptation enables them to fly at high altitudes where there is less oxygen.

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23 Section 33-3 Figure 33 10:Vertebrate Lungs Nostrils, mouth, and throat Trachea Lung Air sac Salamander Lizard Primate Pigeon

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25 Invertebrate respiration Invertebrate respiratory organs have Large surface areas Are in contact with air or water If require diffusion they must be moist. Diffusion occurs when particles spread. They move from a region where they are in high concentration to a region where they are in low concentration.

26 Insects Insects do not breathe the same way that we do. Oxygen travels to insect tissues through tiny openings in the body walls called spiracles, and then through tiny blindended, air-filled tubes called tracheae.

27 Insects To simplify the insect respiratory system, it acts like a sponge. The sponge has small holes that lets water into the sponge moistening the sponge. Similarly, the spiracle openings allows air into the system bathing the insect's tissues with oxygen. Carbon dioxide, a metabolic waste, exits the body through the spiracles.

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29 Section 29-2 Figure 29 9 Invertebrate Respiratory Systems Gill Siphons Tracheal tubes Movement of water Insect Spiracles Mollusk Airflow Spider Book lung

30 Plants Plants do breathe - they give out carbon dioxide and absorb oxygen from the air that surrounds them. Their tissues respire just as animal tissues do. Plants, however, do not have lungs or a blood stream, so we cannot say that they breathe in the same way as animals.

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32 All parts of the plant respire, the leaves, the stem, the roots and even the flowers. The parts above the soil get their oxygen directly from the air through pores. The pores in the leaves are called stomata (singular: stoma). The pores in the branches of trees are called lenticels.

33 Plants We also have to be careful when studying green plants because in the light the green parts of these plants carry out photosynthesis as well as respiration.

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35 Plants Photosynthesis does the opposite of respiration. Carbon dioxide is absorbed and oxygen is produced. In order to study respiration in green plants, we must block out the light, because although green plants respire all the time they only photosynthesize in the light