BAI GIANG HE HO HAP (respiratory system)

Purves et al., Life: The Science of Biology Respiratory system Respiratory system Key processes and concepts • Function of the respiratory system The role of O2 in cellular respiration External and internal respiration • Properties of respiratory gases related to the diversity in structures of respiratory systems in animals • Physical basis of the transport of respiratory gases and lung ventilation: diffusion , bulk flow and related equations; ideal gas law, poiseuille's law, surface tension, partial pressure • Structures of respiratory system in human: conducting zone, respiratory zone, alveolus, respiratory membrane, pleural sac • Lung ventilation and bulk flow: atmospheric pressure (Patm), alveoli pressure (Palv), negative intrapleural pressure (Pip) – Respiratory muscles – Lung compliance, pulmonary surfactant • Gas exchange at the lungs and at the tissues –diffusion and partial pressure • The transport of oxygen in the circulation , oxygen saturation of Hemoglobin, PO250 • Cacbonic anhydrase and the transport of CO2 in the circulation • Control of respiration Biochemical or Internal Respiration (Hô hấp trong) versus Physiological or External Respiration (hô hấp ngoài) Internal respiration deals with converting food energy to ATP External respiration deals with the mechanics of moving oxygen from the atmosphere into the lungs and to the tissues and with moving carbon dioxide from the tissues and the lungs to the atmosphere Specific terms • Pneumo- -Pneumothorax -Pneumonia -Pneumograph -Pulmonary system THE BIG PICTURE IN RESPIRATION • Function is to maintain levels of CO2 and O2 in body tissues • Homeostatic Systems help maintain ideal levels of O2 and CO2 Why living organism need Oxygen? Why we need to breath constantly? ATP — each cell must make its own ATP —ATP is not stored by cells to any substantial extent Nguồn: C.L Standfield 2011 ATP production http://www.windows2universe.org/physical_science/chemistry/oxygen_molecular.html •aerobic catabolism: Glucose + O2 -> 38 ATP + CO2 +H2O •anaerobic glycolysis: Glucose-> ATP + lactic acid The amount of ATP produced is nearly 20 times higher when O2 is present Properties of respiratory gases related to the diversity in structures of respiratory systems in animals • Percentages of CO2 and O2 in atmosphere • Solubility of CO2 and O2 in fresh and in salt water • Concentration of CO2 and O2 in air and water • Density of gases and water Gases in Atmosphere: –Nitrogen= 78% –Oxygen= 21% –Carbon Dioxide = 0.03% Partial pressure • Partial Pressure Definition and Units • At sea level atmospheric pressure Patm= 760 mm Hg Patm = P + PN2 + PCO2 O2 – PO2 = 760 mm Hg X 21% = 160 mm Hg – PN2= 760 x 78% =593 mm Hg – PCO2= 760 x 0.03% = 0.23 mm Hg Definition of PO2 50 • This is the partial pressure of oxygen at which 50% of the hemoglobin becomes saturated with O2 – The higher the PO2 50 the lower the affinity of hemoglobin for oxygen – The lower the PO2 50 the higher the affinity of hemoglobin for oxygen - at tissues: creased metabolic activity -> ↑ CO2 -> ↓pH -> ↑ PO2 50 -> affinity of Hb for O2 ↓ -> O2 is released - at the lungs: pH ↑ -> ↓ PO2 50 -> affinity of Hb for O2 ↑ -> O2 binds to Hb easily Effects of temperature and pH on hemoglobin association curve Bohr effect CARBON DIOXIDE TRANSPORT • Dissolved CO2: – 7% • Bound to Hemoglobin (carbaminohaemoglobin) : 23% • BICARBONATE IONS (HCO3- ) in red blood cells: 70% Cacbonic anhydrase CO2 + H2O H2CO3 H+ + HCO3- • Carbamino effect: Hb + CO2 HbCO2 (carbaminohemoglobin) Increased Pco2 -> Increased Binding of CO2 to Hb decreasing the Hb-O2 affinity -> increased O2 release from HbO2 • Haldane effect: Po2 rises -> increased CO2 unloading At the tissues Cacbonic anhydarse (CA) CA CO2 + H2O < > H2CO3 < > H+ + HCO3- • CO2 is converted to other form ->maintain pCO2 gradient -> increase CO2 solubility •Maintain plasma pH At the lungs Control of Respiration •peripheral chemoreceptor: PO2[...]... temperature V : the volume of gas (L) When n, T are constant -> the pressure is inversely proportional to the volume of gas to change Palv -> the volume of alveoli must be changed How to create the change in alveoli volume? • Lungs are elastic and the changes in the volume of the lungs/alveoli are generated by the changes in the thoracic cavity • The changes in the volume of the thoracic cavity is... between the atmosphere (Patm) and alveoli (Pavl) Q= ΔP R Patm: atmospheric pressure Pavl: intra-alveolar pressure -ΔP: Patm-Pavl -R: the resistance to the flow ΔP = Pair - Pavl •inspiration/inhalation: Patm > Pavl • expiration/exhalation Patm < Pavl How to have ΔP ? • ΔP= Patm – Pavl • Patm is constant (760 mmHg) Palv should be changed ! the ideal gas law RT P =n V P : gas pressure (atm or mmHg ) n : the... (primary) Bronchus/bronchi (phế quản) • Secondary bronchi • Tertiary bronchi – respiratory zone Trachea (Khí quản) • 10-11 cm long, 2-2.5 cm in diameter, run parallel wit h and anterior to the esophagus • 15-20 C-shaped bands of cartilage •In the epithelium lining the conducting zone ( the larynx and the trachea, also bronchi but lesser extent): − Goblet cells secret mucus trapping foreign particles in... into esophagus •Branches in to left and right bronchi surrounded by cartilage rings Conducting zone: conducts air from the larynx to the lungs Respiratory zone: sites of gas exchange within the lungs • 300 million alveoli in two lungs -> total surface of 100m2 • Alveolar pores allow equilibration of pressure within the lung Cross section of an alveolus • Type I alveolar cells: epithelial cells making... gas transport between the lungs and the tissues (bulk flow) 4 Respiratory gas exchange between the blood and tissues (diffusion) Lung ventilation Pleura and intrapleural sac Áp suất khoang màng phổi thành lồng ngực lá thành /sac túi màng phổi lá tạng Cơ ho nh Áp suất trong phổi/phế nang Lung ventilation is driven by bulk flow • Air (containing O2 and CO2) moves into and out of the lungs by bulk flow... Inspiratory muscles: Diaphragm (Cơ ho nh), external intercostals (cơ liên sườn ngoài) - Expiratory muscles: Internal intercostals (Cơ liên sườn trong), abdominal muscles: Actions of respiratory muscles generate changes in the volume of the lungs Hít vào Thở ra Cơ liên sườn ngoài giãn Cơ liên sườn trong và các cơ bụng co chỉ khi thở ra sâu/cố sức Cơ liên sườn ngoài co Cơ ho nh co Cơ ho nh giãn Intrapleural pressure...Henry’s Law (calculating how much gas can dissolve in a solution) C=kxP C= molar concentration of dissolved gas (moles/liter or mM/L) P= partial pressure of gas (mm Hg) k = solubility constant of gas in solvent (moles/liter mm Hg or mM/L mm Hg) k = C/P (solubility (k) = C (molar concentration of the gas) divided by P (partial pressure of the gas) Oxygen Solubility: Air... thở ra sâu/cố sức Cơ liên sườn ngoài co Cơ ho nh co Cơ ho nh giãn Intrapleural pressure (Pip) Áp lực(âm) trong khoang màng phổi • Pip is always negative ( keep the lungs from collapsing during breathing ... of Biology Bulk flow/convection and diffusion Diffusion- relies on thermal energy; efficient over short distances: 0.5m Bulk Flow (Q)/convection relies on fluid pressure gradient; 0.0001m Uses ATP to generate pressure gradient; 0.6m 0.0000 2m Modified Fig 21.6 Hill at el, 2008 Works well over long distances Purves et al., Life: The Science of Biology Bulk flow and diffusion are both used in respiratory... 34 > problem in blood and role of hemoglobin Carbon Dioxide Solubility: Air vs Water Air Water 0.052 mM/LmmHg 0.03 mM/LmmHg kair / kwater = 1.7 Solubility CO2 in Water / Solubility O2 in Water 0.03 / 0.0015 mM/LmmHg = 20 Air versus Water 1 Air has 209 ml oxygen/liter 2 Water has 6.6 ml oxygen/liter 3 Water is 1000 times more dense than air Purves et al., Life: The Science of Biology Bulk flow/convection