5. Other questions….. How does size of organism, its habitat and its metabolic activity affect the structure of its respiratory surface?
6. The lowly animals…… Use of cell membrane as respiratory medium Part of the body with direct contact with the respiratory medium is used for respiration E.g. poriferans, protists, cnidarians
7. Highly evolves animals (tayoyun) Use of a highly extensive respiratory structure Respiratory medium is separated from blood and capillaries Give examples- student number 12
9. The commoners (common respiratory organs) Tracheal system Arthropods Gills E.g. amphibians, fish Lungs E.g. birds, mammals
10. Angproblemangtubig, bow Due to low amount of oxygen per volume its energy cost is higher compared to air Ventilation is present if oxygen is minimal Increased contact between respiratory medium and respiratory surface Without ventilation region of high O2 conc and region of high CO2 conc will occur
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12. Fish ventilation They swim against the current What is the consequence of this method of ventilation?
13. Countercurrent exchange Water moves opposite the direction of blood Gills are highly extensive Lessens the energy cost
14. Countercurrent exchange pa rin….. Ensures the presence of a diffusion gradient between the respiratory medium (water) and transporting medium (blood) Very efficient
19. Tracheal system Direct transport of gas between respiring cells and respiratory medium Tubular structure Trachea- large tube Plural tracheae Spiracles- opening to the outside Tracheole- fine tubes directly connected to cells
20. Lungs Confined inside the body cavity Circulatory system bridges the respiratory medium and transport tissue Respiratory structure- epithelium + dense capillaries
23. Mammalian respiration Give the sequence of structures where gases will travel from the environment to the body then back to the environment
24. Air we breath Filtered by hairs and cilia Warmed, humidified and sampled for odors
25. Mammalian respiration…. The act of swallowing moves the larynx upward tipping the epiglottis over the glottis Glottis- opening of the windpipe Larynx- adapted as voicebox Syrinx- vocal organ of birds Found at the base of the trachea Produce sound without the vocal chords found in mammals
26. Sound Sound: produced when voluntary muscles stretch and vibrate during the process High-pitched sound: tight, rapid vibration Low-pitched sound: less tense, slow vibration
27. The Phlegm Epithelial lining is covered with mucus and beating cilia Mucus traps contaminant, while, the cilia moves this to the pharynx where it can be swallowed
37. Factors that affect breathing Tidal volume- volume of air inhaled and exhaled in each breath Ave human tidal volume is 500 ml Vital capacity- max tidal volume during forced breathing 3.4 L female; 4.8 L male Residual volume- air left in the lungs during exhalation Lungs hold more air than the vital capacity
38. Old age Age or disease decrease the elasticity of the lungs Residual volume increases at the expense of vital capacity Max O2 conc in the alveoli decreases Gas exchange efficiency is decreased
39. Bird breathing Presence of air sacs Do not function directly in gas exchange; acts as bellows Lungs and air sacs- ventilated during breathing Presence of parabronchi rather than alveoli Air moves in one direction Air is completely exchanged Max O2 conc is higher in birds than in mammals
41. Regulation of Breathing Breathing – controlled by the medulla oblongata and the pons This ensures that respiration is coordinated with circulation Medulla oblongata- major control center of breathing Control center in the pons works synergistic with the control center of the medulla oblongata
42. Regulation of Breathing Negative feedback- helps maintain breathing Stretch sensors- found in the lungs send impulses to the medulla (inhibits the breathing control center) Medulla- monitors CO2 level of the blood CO2 conc is detected through slight change in blood and tissue fluid pH Carbonic acid lowers pH Drop in pH increases rate of rate and depth of breathing
43. Oxygen Concentration Oxygen Concentration- have little effect to breathing control center Severe depression of O2 conc stimulates O2 sensors in the aorta and carotid arteries to send alarm signals Breathing rate is increased by the control centers Increase in CO2 conc is a good indicator of decrease in O2 conc
44. Hyperventilation Excessive deep, rapid breathing inc CO2 conc in the blood Breathing centers temporarily stops working Impulses to the rib muscles and diaphragm are inhibited Breathing resumes when CO2 conc inc
45. Different Factors Affect Breathing Nervous and chemical signals affects rate and depth of breathing Most efficient if it works in tandem with the circulatory system E.g. Exercise: inc cardiac output-inc breathing rate Enhances O2 uptake and CO2 removal
46. Respiratory pigments: transports gases and buffers the blood Low solubility of O2- problem if O2 is transported via the circulatory system E.g. Normal human consume 2L of O2 per minute Only 4.5 ml of O2 can dissolve into a L of blood in the lungs If 80% dissolved O2 would be delivered, 500 L of blood should be pumped per minute (a ton per 2 mins) Unrealistic!!!! Special respiratory pigments are used
47. Respiratory Pigments Transports O2 instead of dissolving into a solution Inc O2 that can be carried in the blood (~200 mL O2 per L in mammalian blood) Decreases cardiac output (20-25 L per min)
48. Respiratory Pigments Binds O2 reversibly Loads O2 from respiratory organ; unloads in other parts of the body Hemocyanin- found in hemolymph of arthropods and many mollusks Copper- acts as the oxygen-binding component Hemoglobin- respiratory pigment of all vertebrates
49. Hemoglobin Consists of four heme subunits Iron acts as the binding site of O2 Loading and unloading of O2 depends on the property of each subunits called cooperativity Affinity is dependent to the conformation of each subunit Binding of one O2 molecule to one subunit induces the inc in affinity of other subunits Unloading of one O2 molecule decreases the affinity of other subunits
50. Dissociation Curves of Gases Cooperativity of heme subunits is shown in a dissociation curve Steep slope- slight change in Po2 causes substantial loading or unloading of O2 Because of cooperativity, slight drop in Po2 causes a relatively large inc in O2 to be unloaded
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52. The Bohr Shift A shift to the right of the oxygen hemoglobin dissociation curve Brought about by increase CO2 or low blood pH Decrease in affinity of hemoglobin to O2 Greater efficiency of O2 unloading
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54. Carbon Dioxide transport Hemoglobin- also transports CO2 not only O2 Assists in buffering the blood Blood released by respiring cells: 7%- transported in the solution of blood plasma 23% - bind to amino group of hemoglobin 70% - transported in the blood in the form of carbonic acid
55. Carbon Dioxide Transport CO2- converted in the red blood cells into bicarbonate Reacts first with water to form carbonic acid (carbonic anhydrase) Dissociates into H+ and bicarbonate H ions- attach to different sites in the Hb and other proteins Bicarbonate ions- diffuse into the plasma Movement of blood through the lungs reverses the process favoring the conversion of bicarbonate to CO2
56. Deep-diving air breathers Stockpile oxygen- O2 is reserved in the blood and muscles (e.g. Weddell seal) High percentage of myoglobin Dec heart rate and O2 consumption 20-min dive- O2 in myoglobin is used up Energy is derived from fermentation rather than respiration
