Breathing
Muhtasari
You have taken roughly twenty thousand breaths since this time yesterday and noticed almost none of them. Each one is a small piece of engineering: a set of muscles changes the shape of your chest, the pressure inside it drops below the pressure of the room, and air does the rest by moving from where there is more of it to where there is less. Nothing sucks the air in. It is pushed in, by the atmosphere.
This lesson takes that machinery apart. You will trace the path air follows from the trachea down to the alveoli, learn the exact sequence of muscle, volume and pressure that the specification wants for inhaling and exhaling, and see why a gas exchange surface the size of a badminton court is folded up inside your ribcage. By the end you should be able to label any diagram of the respiratory system, write either breathing sequence out in order without hesitating, and explain the movement of both gases across the alveolar wall in terms of one idea: a difference in concentration that the body works constantly to keep steep.
Malengo
- The respiratory (breathing) system takes air into and out of the body so that oxygen from the air can diffuse into the bloodstream and carbon dioxide can diffuse out of the bloodstream into the air. The lungs are in the upper part of the body (thorax), protected by the ribcage and separated from the lower part of the body (abdomen) by the diaphragm. Students should be able to recognise the following on a diagram of the respiratory system: ribs, intercostal muscles, diaphragm, lungs, trachea, bronchi, bronchioles, alveoli.
- To inhale: the intercostal muscles contract, pulling the ribcage upwards; at the same time the diaphragm muscles contract, causing the diaphragm to flatten; these two movements cause an increase in the volume of the thorax; the consequent decrease in pressure to below that of the air surrounding the body results in atmospheric air entering the lungs. To exhale: the intercostal muscles relax, allowing the rib cage to move downwards; at the same time the diaphragm muscles relax, allowing the diaphragm to resume its domed shape; these two movements cause a reduction in the volume of the thorax; the consequent increase in pressure results in air leaving the lungs.
- The alveoli provide a very large surface area, richly supplied with blood capillaries, so that gases can readily diffuse into and out of the blood.
Ramani ya mawazo
Mada hii imechorwa ili uone jinsi mawazo yanavyounganika.
Fungua ramani ya mawazo kwenye programu
Maelezo ya Somo
Dokezo Kamili la Somo Linapatikana kwenye Programu ya Green Bridge
Pata programu ya Green Bridge CBT kwenye simu au kompyuta yako kwa maktaba kamili ya IGCSE: mitihani ya miaka iliyopita, miongozo ya usahihishaji, ramani za mawazo, kadi za marudio na masomo ya sauti.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Breathing. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- Which structure separates the thorax from the abdomen? A. The ribcage B. The diaphragm C. The trachea D. The bronchioles Answer: B
- Which of these happens when a person inhales? A. The diaphragm relaxes and becomes domed B. The volume of the thorax decreases C. The intercostal muscles contract and the ribcage moves upwards D. The pressure inside the thorax rises above atmospheric pressure Answer: C
- Approximately what percentage of exhaled air is carbon dioxide? A. 0.04% B. 4% C. 16% D. 21% Answer: B
- Which feature of the alveoli most increases the rate at which oxygen diffuses into the blood? A. Rings of cartilage that hold them open B. A large surface area with walls one cell thick and many capillaries C. A thick layer of muscle in their walls D. Cilia that sweep mucus away from them Answer: B
- In the lungs, carbon dioxide moves from the blood into the air inside an alveolus. Which statement explains this movement? A. Energy is used to pump carbon dioxide across the alveolus wall B. The concentration of carbon dioxide is higher in the blood than in the alveolus C. The wall of the alveolus is thick, which slows the gas down D. Breathing out increases the concentration of carbon dioxide in the alveolus Answer: B
Fanyia kazi maswali haya kwenye programu
Fanyia kazi maswali haya kwenye programu
Vitabu Vinavyopendekezwa
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Breathing? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
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