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Respiratory System trachea bronchus (bronchi) bronchioles.

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Presentation on theme: "Respiratory System trachea bronchus (bronchi) bronchioles."— Presentation transcript:



3 Respiratory System trachea bronchus (bronchi) bronchioles

4 Bronchioles & Alveoli bronchiole alveoli

5 Nasal Cavity Nasal cavity possess hairs for trapping large dirt particles wall of nasal cavity lined with ciliated epithelium and mucus-secreting cells to trap dirt and bacteria

6 near surface are numerous blood vessels so incoming air are warmed, moistened & filtered before entering lungs

7 Pharynx & Larynx

8 pharynx belongs to both respiratory & digestive system glottis is the opening of larynx and it is covered by epiglottis during swallowing

9 larynx consists cartilage at the entrance of trachea within the cartilage are two membranes, vocal cords to produce sound waves

10 Trachea (Windpipe) and Bronchi trachea lies in front of oesophagus and extended into thoracic cavity at the lower end of trachea is divided into two bronchi which subdivides into many bronchioles

11 each bronchiole terminates in hollow, lobed air sacs called alveoli inner lining of the trachea produces mucus and possess cilia

12 mucus are used to trap the dirt & germ while cilia are used to waft the mucus towards the throat, it is then either coughed out or swallowed. Those coughed out are called phlegm wall of trachea strengthened by C-shaped cartilages to keep trachea open

13 Alveoli Adaptations thin wall ( only one-cell thick) –short diffusion distance for gases folding shape and numerous alveoli –large surface area for diffusion of gases

14 lots of capillaries present –maintain high concentration gradient of gases moist surface –to dissolve gases for diffusion

15 Structure of Lung lungs are protected by the thoracic basket which is made up of vertebrae, ribs and sternum each lung is surrounded by two pleural membranes

16 the inner membrane is in contact with the lungs and the outer membrane lines against the walls of the thorax and diaphragm between the two membranes is pleural cavity which contains a pleural fluid secreted by the membranes

17 pleural fluid lubricates the pleura so to reduce friction as the pleural membranes rub against each other during breathing

18 rib pleural membranes alveoli pleural fluid Intercostal muscles bronchiole larynx trachea - have ring of cartilage left lung left bronchus heart diaphragm

19 Thoracic Basket (rib cage) vertebrae sternum ribs pleural cavity - absorb shock 2 pleural membranes

20 Gaseous Exchange in Alveoli tissue Lungs(alveoli) CO 2 (by plasma and in form of HCO 3 - ) O 2 + haemoglobin atmosphere CO 2 O2O2 oxyhaemoglobin (by red blood cell)

21 Heart Deoxygenated blood Oxygenated blood Lung Pulmonary artery Pulmonary vein Tissue Gaseous Exchange in Alveoli

22 air moves out during expiration air moves in during inspiration O2O2 CO 2 cell in capillary wall plasma cell in alveolar wall mucus red blood cell deoxygenated blood from pulmonary artery oxygenated blood to pulmonary vein

23 Mechanism of Breathing brought about by the action of diaphragm & intercostal muscles divided into two processes : inhalation (inspiration) & exhalation (expiration)

24 Inspiration (Inhalation) Diaphragm muscle - contract Intercostal muscle - contract Diaphragm - flattened ribs & sternum - move upward & outward

25 thoracic cavity expands (volume increases) air pressure in lung is lower than atmospheric pressure so air rushes in lungs inflated (expand) Inspiration (Inhalation)

26 Expiration (Exhalation) intercostal muscles relax diaphragm muscles relax diaphragm becomes dome- shaped ribs and sternum move downwards & inwards

27 thoracic cavity volume decreases air pressure inside lungs increases air forces out lungs deflated

28 Walking & Running time (seconds) lung volume ( cm ) 3 at rest lung volume ( cm ) time (seconds) during exercise

29 Calculations of the Rate and Depth of Breathing From the graphs the volume of air he breathed in per minute at rest and during exercise can be measured :


31 If the percentage by volume of oxygen in atmospheric air is 21% and that in exhaled air is 16%. Then the volume of oxygen retained in the body per minute can then be calculated : At rest : 18 x 500 x (21-16)% = 450cm 3 During exercise : 27 x 2000 x (21-16)% =2700cm 3

32 CO 2 remains Constant during Exercise CO 2 concentration in blood remains CONSTANT muscles release CO 2 ventilation rate increases + 

33 The graph of Lung capacities

34 Tidal Volume –amount of air entering & leaving the lungs during normal breathing –during exercise → can increase volume

35 –during exercise → cannot increase the capacity –increase only after prolong training –maximum air exhaled after taking the deepest inhalation Vital Capacity Vital Capacity

36 –volume of air remaining in the lungs which cannot be expelled even after forced exhalation Residual Volume Residual Volume

37 Smoking & Health Effects on health : (I) Tar : (i) carcinogenic ( producing cancer ) (II) Nicotine : (i) cause heart diseases carbon monoxide Composition of a cigarette : = cigarette+ tar+ nicotine

38 Smokers’ lung

39 (ii) dependence (iii) retards growth of foetus (III) Carbon Monoxide : (i) combines irreversibly with haemoglobin and prevents it from carrying oxygen + COhaemoglobin (ii) decrease in physical fitness (iii) cause air pollution carboxyhaemoglobin

40 Smoking and Health Hazards 1.Lung Cancer Smoking increase the risk of lung cancer 2.Heart disease Nicotine increases the workload of heart increase the rate of heart attack

41 Smoking and Health Hazards 3.Chronic bronchitis Smoking causes inflammation of trachea and bronchitis The severe chronic bronchitis can cause death 4.Emphysema Causes of "smoker's cough" Smoker cough causes damage of alveolar wall in lungs

42 Passive Smoking process of breathing in smoke from cigarette smokers causes nose, throat & eye irritations Warning DO NOT SMOKE !!!!!

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