SHAP001 Week 8 Coursebook PDF

SHAP001 Human Anatomy and Physiology Week 8 Course Book PRE-TUTORIAL A: SIGNIFICANCE OF THE RESPIRATORY SYSTEM Oxygen must be continuously supplied from the atmosphere and carbon dioxide...

SHAP001 Human Anatomy and Physiology Week 8 Course Book PRE-TUTORIAL A: SIGNIFICANCE OF THE RESPIRATORY SYSTEM Oxygen must be continuously supplied from the atmosphere and carbon dioxide eliminated if cells are to remain healthy. The lungs provide a respiratory exchange surface over which diffusion can occur between the air and the blood. The cardiovascular system provides the link between the interstitial fluid (aka tissue fluid) that bathes cells and the exchange surfaces of the lungs. The circulating blood carries oxygen from the lungs to peripheral tissues and transports carbon dioxide from tissues to the lungs. Diffusion at the lungs occurs across the walls of capillaries, where the vessels pass very close to the enclosed air in the delicate alveoli. The distance between the capillary wall and the air in an alveolus is in the order of only 1μm. The metabolic demands of body cells are such that the exchange surfaces of the lung must be very large, and in fact they are roughly 80 times the total surface area of the body. The functioning of the respiratory system rely on both: (Fill in the blanks) B____ Ulk f_____ of air/water – from _____ pressure to _____ pressure low high low Simple d____________ iffusion - from _____ concentration to _____concentration high low Right Left Alveoli sacs Lungs cardiovascular system Diaphragm cells SHAP001 Week 8 Coursebook 1  PRE-TUTORIAL A: ANATOMY OF CONDUCTING ZONE Structures which provide assageways for air travel into and out of the lungs oral cavity nasal cavity pharynx trachea bronchi vonchioles alveoli HEART SHAP001 Week 8 Coursebook 2  Label the diagrams: nasalcavity Externalnaresnostrils pharynx oralcavity trachea Larynx c shaped Rightmainprimary cartilage bronchus leftmain primary bronchus Rightlung leftlung diaphragm brothers L Deoxygenatedblood from pulmonary oxygenatedblood artery frompulmonary vein pores alveolar capillaries alveoli SHAP001 Week 8 Coursebook 3  A. Nasal Cavities with hair tilter allergenspathogens fun trap bacterialdustparticles mucus goblet mucusproducedby ggff.IS bacterialdus Fracnea 198 in Gobletcell Epithelialcell 5119 4 949 III feed Function breathingcreatingvocalsounds B. Larynx preventingfoodparticles fromgetting intotrachea incoming capillaries warmaUP entering wde9ha99wriayhksfrom iprfffffefae.it controlsairflowinand outoftherespiratory 19 99ationofthetemperatureofthebreath SHAP001 Week 8 Coursebook 4  C. Trachea food air D. Bronchi and Bronchioles hereis aserousfluidwithintheplueracavity arynx unctions inflation Lubicatedsurfacetoallowsmooth anddeflationoflungswhenbreathing against rub shapedcartilage Reducefrictionwhenthesurfaces achother rachea bronchi pleural Bronchioles costal costal alveoli costal replanting to the SHAP001 Week 8 Coursebook 5  is connectslungsand it wherethepulmonary Hilumvessels enterand exit thelungs PRE-TUTORIAL A: ANATOMY OF RESPIRATORY ZONE The alveoli (air sacs) and their surrounding capillaries: Iand alveoli95T c's 99 alveoli ducts SHAP001 Week 8 Coursebook 6  TUTORIAL A: GAS EXCHANGE AT ALVEOLUS gas waterfilm agl airsac blood blood 5 Features of the Respiratory Surface: The site of gas exchange is called a respiratory surface (i.e. _____________ in alveoli human) where it occurs by diffusion. To maintain the maximum possible rate of diffusion, respiratory surface has the following characteristics: 1. Permeable canpassthrough 2. Thin (__-cell-thick) 1 3. Moist 4. Efficient transport system _______________________________________________________________ Network ofcapillaries transportCO2out exhale _______________________________________________________________ andtransport 02in inhale 5. Large ____________ to _____________: increase volumeratio __________________________ area for diffusion surggy SHAP001 Week 8 Coursebook 7  Classwork – finding out SA: Vol ratio 3 I 3 I 3 1 SA = 54 ____ Vol= 27 ____ SA =162 ____ Vol= ___ 27 6sides 27cubes units SAE 3 33 995,54 Vol I w I d 27cubes 27 SHAP001 Week 8 Coursebook 8  TUTORIAL A: PROTECTION OF THE LUNGS Lungs are in ____________ cavity and protected by rib cage. thoracic Ribs intents s sternum diaphragm cartilage The pleural membranes, serous in nature, enclosing the lung. Serous membrane line free body surfaces that are sealed off from the outside environment and specialise as pleural coverings of the lung. The parietal pleura lines the entire inside free surface of the chest cavity and covers the top of the diaphragm. The visceral or pulmonary viscera adhere to the lungs. The intrapleural cavity is the sealed potential space between the parietal and visceral (pulmonary) pleura. The two membranes touch at many places, particularly during lung inflation while inhaling. The serous membranes secrete a small quantity of fluid into the pleural cavity to reduce friction. There is contact and rubbing between these two layers of membranes as the lungs inflate and deflate during breathing. inside outside SHAP001 Week 8 Coursebook 9 SHAP001 Week 8 Coursebook 10  TUTORIAL A: GAS EXCHANGE AT ALVEOLAR SURFACE – THE SIMPLE DIFFUSION Gas exchange across the alveolar surface: aka water film Gas exchange – oxygen and carbon dioxide: concentration The partial pressure (measured in mmHg or kPa) is the pressure that a particular gas exerts in a gas mixture. The pressure is caused by the impact of moving molecules against a surface. Respiratorysystem Pulmonary artery PulmonaryVein heart heart capillivies cardiovascularsystem The composition of alveolar air remains relatively unchanged because _________ we _______________________________________________________________. have constant inspiration expirationat alltimes SHAP001 Week 8 Coursebook 11  TUTORIAL A: VENTILATION MECHANISM – THE BULK TRANSPORT Ventilation is brought about by the actions of breathing, which include ________________(inspiration / breathing in) and __________________ (expiration / inspiration expiration breathing out). Both actions involve the i_________________ muscles and the intercostal _____________ muscles. diaphragm To understand breathing, we must first understand the Boyle’s Law. In other words, ___ volume → ___ pressure ___ volume → ___ pressure The flowchart below summarizes how breathing is brought out: volumeof lungs pressure of air fromatmosphere 1 increase 88 A. Inspiration (active) and Expiration (passive) flow intolungs Inspiration effort Expiration 1. Intercostal _____________ muscle and relax 1. Passive process achieved mainly by the _____________ muscle contract to bring elastic recoil of the thoracic cage (i.e. the diaphragm the rib cage upward and outward relax of diaphragm and intercostal muscle) → recoil compresses the lungs 2. Increase the v________ Olume of thoracic cavity 2. Volume of thoracic cavity decrease _______ 3. Decrease _________ in lung pressure 3. _______ in lung pressure increase 4. Air flows along the pressure gradient 4. Air flows along the pressure gradient from ______________ to from ______________ to atmosphere lungs _____________ _____________ lungs atmosphere SHAP001 Week 8 Coursebook 12  B. Three Factors Influencing Airway Resistance These three factors are: diameter of bronchioles, connective tissue of the lung and surface tension. 1. Diameter of bronchioles (a) Bronchodilation -increase ________ air flow; could be induced by epinephrine (= a___________) drenaline sympathetic nerve stimulation (b) Bronchoconstriction -decrease ________ air flow; could be induced by histamine parasympathetic nerve stimulation cold air anaphylactic shock (serious, life-threatening allergic reaction) asthma SHAP001 Week 8 Coursebook 13  2. Connective Tissue of the Lungs – the ease the lungs can expand In emphysema (over-inflation of the alveoli due to cigarette smoking), the elastic tissue has been damaged. Due to the poor elastic recoil, patients have no problem inflating the lungs but have extreme difficulty exhaling air. 3. Surface Tension of the alveoli and distal bronchioles keep Normally, epithelium produces s____________, 89 929 58 unfacetant an oily secretion, which keeps these tubes open and prevent them from collapsing during exhalation. In infant respiratory distress syndrome (IRDS), without surfactant, infants are not strong enough to inflate their alveoli. SHAP001 Week 8 Coursebook 14  TUTORIAL A: NEURAL CONTROL OF BREATHING brainstem Respiratory centre (B_______________ centre) in ________________ reathing contract inhale IOWPH too much CO2 SHAP001 Week 8 Coursebook 15  TUTORIAL A: TRANSPORT OF CARBON DIOXIDE Carbon dioxide is carried by blood in 3 different ways: (1) As dissolved gas (5%) They dissolve in plasma and is carried in solution. (2) Combined with protein (20%) 20% binds to the amino groups of plasma proteins and hemoglobin to form carbamino compounds – chiefly carbaminohemoglobin (HbCO2) o carbon dioxide does not compete with oxygen; they bind to different moieties on the hemoglobin molecule o therefore, hemoglobin can transport O2 and CO2 simultaneously (3) As carbonic acid (75%) CO2 + H2O → __________ → HCOs ________ + H2O _______; this reaction is reversible H 2603 and catalysed by carbonic anhydrase (enzyme) 97 3 95 20 20 s g1 SHAP001 Week 8 Coursebook 16  PRE-TUTORIAL B: TRANSPORT OF OXYGEN A. Basics of Oxygen Transport in Blood and the Partial Pressure top In'é ftp.ebpfife chains crosssection lateral Haemoglobin contains ____4 polypeptide chains, each of which contains an Fe ____ atom to bind _____________. oxygen Oxygen binding to the iron is how haemoglobin transports oxygen around the body. The fact is haemoglobin’s affinity for oxygen is NOT always the same. (Fill in the blanks) In some places, we want our haemoglobin to have a high affinity for oxygen, so it can easily __________ it out of the air. pick attraction And in others, we want it have a low affinity for oxygen, so it can release _________ the oxygen molecules to feed our cells. So what determines the strength of affinity? It has to do with “partial pressure”. B. Partial Pressure of Oxygen The partial pressure of a given gas ( ) is defined as the pressure exerted by that gas ( ) alone in a gas mixture such ( asair ). 02 SHAP001 Week 8 Coursebook 17  TUTORIAL B: TRANSPORT OF OXYGEN (CONTINUE) C. Oxygen Dissociation Curve When the % O2 saturation of blood is plotted against the oxygen tension (partial pressure), an oxygen dissociation curve is obtained. The curve is S ___-shaped. dissolved The lessO2is more in capillaries the 02is beingreleased from haemoglobin to use by body partial pressure oxygendissolved inblood The significance of the S-shaped curve, particularly the steep region, is: A _____ drop in oxygen tension brings about a _____ fall in % O2 saturation. small sharp In other words, if the oxygen tension falls as a result of the tissue utilizing oxygen at a faster rate, the haemoglobin gives up more of its oxygen. Haemoglobin has a _________ affinity of O2 (i.e. takes up O2 easily) where oxygen tension is high (i.e.highungs the _________), whereas Haemoglobin has a _________ affinity of O2 (i.e. gives up O2 easily) where oxygen 10 tension is low (i.e. theWtissue _________) More importantly, a small drop in oxygen tension brings about a _____ fall in % O2 saturation. sharp This property makes the haemglobin an efficient respiratory pigment. Classwork Sketch a curve on the graph above when carbon monoxide is inhaled. COhas200foldsstrongeraffinitytosame binding site of Oz in haem SHAP001 Week 8 Coursebook 18  D. Bohr Effect The Bohr Effect is a physiological phenomenon first described in 1904 by the Danish physiologist Christian Bohr, stating that hemoglobin's oxygen binding affinity is inversely related both to (1) pH, (2) concentration of CO2 and (3) temperature. The oxygen dissociation curve will shift to the RIGHT when there is: (1) ____ CO2 concentration hardforoxygento (2) ____ pH bind to the (3) ____ temperature haemoglobin Classwork – Scenario: Performing Vigorous Physical Exercise LowerO2Saturation higher0 saturation Significance of Bohr Effect: The oxygen dissociation curves shift to the right means______ oxygen is supplied to more the tissues. SHAP001 Week 8 Coursebook 19  E. Myoglobin Myoglobin is common in ___________ muscle of mammals and is responsible for the Skeletal colour of ‘red’ muscle. It is particularly abundant in animals which need extremely large amount of oxygen, such as seal, and in the flight muscles of birds. moreoxygenis held bymyoglobin Significance of the O2 dissociation curve to myoglobin’s functioning: Compared to Haemoglobin, O2 dissociation curve of myoglobin shifts to the __________. This means that the myoglobin has a ________ affinity for oxygen. left higher In other words, it remains fully saturated with oxygen at partial pressure well below that required for haemoglobin to give up its oxygen. In fact it only begins to release oxygen when the partial pressure of oxygen is really low. In this way, it acts as a s_________ of oxygen in resting muscle; only releasing it torage have been exhausted, as in vigorous physical when supplies of oxyhaemoglobin exercises. SHAP001 Week 8 Coursebook 20  F. Foetal Haemoglobin Similar to myoglobin, the foetal haemoglobin has an oxygen dissociation curve displaced to the ________ of the adult haemoglobin. left The foetal haemoglobin has a ________ affinity of oxygen than the mother’s blood high so that it can pick up oxygen from the mother’s blood across the placenta. SHAP001 Week 8 Coursebook 21