22-1 chapter 22 lecture outline see powerpoint image slides for all figures and tables pre-inserted...
TRANSCRIPT
![Page 1: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/1.jpg)
22-1
Chapter 22
Lecture Outline
See PowerPoint Image Slides
for all figures and tables pre-inserted into
PowerPoint without notes.
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
![Page 2: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/2.jpg)
22-2
Respiratory System
• Anatomy of the Respiratory System
• Pulmonary Ventilation
• Gas Exchange and Transport
• Respiratory Disorders
![Page 3: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/3.jpg)
22-3
General Aspects
• Airflow in lungs– bronchi bronchioles alveoli
• Conducting division– passages for airflow, nostrils to bronchioles
• Respiratory division– distal gas-exchange regions, alveoli
• Upper respiratory tract– organs in head and neck, nose through larynx
• Lower respiratory tract– organs of thorax, trachea through lungs
![Page 4: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/4.jpg)
22-4
Alveolar Blood Supply
![Page 5: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/5.jpg)
22-5
Alveolus
Fig. 22.11
b and c
![Page 6: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/6.jpg)
22-6
Pleurae and Pleural Fluid
• Visceral (on lungs) and parietal (lines rib cage) pleurae
• Pleural cavity - space between pleurae, lubricated with fluid
• Functions– reduce friction– create pressure gradient
• lower pressure assists lung inflation
– compartmentalization• prevents spread of infection
![Page 7: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/7.jpg)
22-7
Pulmonary Ventilation
• Breathing (pulmonary ventilation) – one cycle of inspiration and expiration (respiratory cycle)– quiet respiration – at rest– forced respiration – during exercise
• Flow of air in and out of lung requires a pressure difference between air pressure within lungs and outside body
![Page 8: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/8.jpg)
22-8
Respiratory Muscles• Diaphragm (dome shaped)
– contraction flattens diaphragm
• Scalenes - hold first pair of ribs stationary
• External and internal intercostals– stiffen thoracic cage; increases diameter
• Pectoralis minor, sternocleidomastoid and erector spinae muscles– used in forced inspiration
• Abdominals and latissimus dorsi– forced expiration (to sing, cough, sneeze)
![Page 9: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/9.jpg)
22-9
Respiratory Muscles
![Page 10: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/10.jpg)
22-10
Neural Control of Breathing
• Breathing depends on repetitive stimuli from brain
• Neurons in medulla oblongata and pons control unconscious breathing
• Voluntary control provided by motor cortex• Inspiratory neurons: fire during inspiration• Expiratory neurons: fire during forced expiration• Fibers of phrenic nerve go to diaphragm;
intercostal nerves to intercostal muscles
![Page 11: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/11.jpg)
22-11
Respiratory Control Centers• Respiratory nuclei in medulla
– Ventral Respiratory Group- primary generator of the respiratory rhythm
– Inspiratory neurons and expiratory neurons, p 877, 878– Dorsal Respiratory Group, integrating center that
receives input from other areas (pons, cehmosensitive area in medulla, peripheral chemoreceptors, and stretch and irritant receptors
• Pons– Pontine respiratory group– Receives input from higher brain centers and
transmits signals to VRG and DRG that modify timing of transition from inspiration to expiration
![Page 12: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/12.jpg)
22-12
Respiratory Control Centers
![Page 13: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/13.jpg)
22-13
Input to Respiratory Centers
• From limbic system and hypothalamus– respiratory effects of pain and emotion
• From airways and lungs– irritant receptors in respiratory mucosa
• stimulate vagal afferents to medulla, results in bronchoconstriction or coughing
– stretch receptors in airways - inflation reflex• excessive inflation triggers reflex• stops inspiration
• From chemoreceptors– monitor blood pH, CO2 and O2 levels
![Page 14: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/14.jpg)
22-14
Chemoreceptors
• Peripheral chemoreceptors – found in major blood vessels
• aortic bodies – signals medulla by vagus nerves
• carotid bodies – signals medulla by glossopharyngeal nerves
• Central chemoreceptors – in medulla
• primarily monitor pH of CSF
![Page 15: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/15.jpg)
22-15
Peripheral Chemoreceptor Paths
![Page 16: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/16.jpg)
22-16
Voluntary Control
• Neural pathways– motor cortex of frontal lobe of cerebrum sends
impulses down corticospinal tracts to respiratory neurons in spinal cord, bypassing brainstem
• Limitations on voluntary control– blood CO2 and O2 limits cause automatic
respiration
![Page 17: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/17.jpg)
22-17
Pressure and Flow
• Atmospheric pressure drives respiration– 1 atmosphere (atm) = 760 mmHg
• Intrapulmonary pressure and lung volume
Boyle’s Law: pressure is inversely proportional to volume
• for a given amount of gas, as volume , pressure and as volume , pressure
• Pressure gradients– difference between atmospheric and
intrapulmonary pressure– created by changes in volume thoracic cavity
![Page 18: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/18.jpg)
Inspiration
Put your hands on your rib cage. Inhale. Notice that the thoracic cage moves up and out. Diaphragm moves down (Fig 22-8, A and C Herlihy)
• This movement increases the volume of the thoracic cavity and lungs.
• As the volume in the lung increases, the pressure in the lung decreases (Boyle’s Law)
• P in the lung < atmospheric P so air flows in 22-18
![Page 19: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/19.jpg)
22-19
Respiratory Cycle
![Page 20: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/20.jpg)
22-20
Passive Expiration
• During quiet breathing, expiration achieved by elasticity of lungs and thoracic cage
• Diaphragm relaxes, moves up. Rib cage moves down and in.
• As volume of thoracic cavity , intrapulmonary pressure and air is expelled
![Page 21: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/21.jpg)
22-21
Forced Expiration
• Internal intercostal muscles – depress the ribs
• Contract abdominal muscles intra-abdominal pressure forces
diaphragm upward pressure on thoracic cavity
![Page 22: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/22.jpg)
22-22
Pneumothorax
• Presence of air in pleural cavity– loss of negative intrapleural pressure allows
lungs to recoil and collapse
• Collapse of lung (or part of lung) is called atelectasis
![Page 23: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/23.jpg)
22-23
Resistance to Airflowthe greater the resistance, the slower the flow
• Pulmonary compliance– The ease with which the lungs expand– change in lung volume relative to a change in
transpulmonary pressure
• Bronchiolar diameter– primary control over resistance to airflow– Bronchoconstriction (reduce airflow)
• triggered by airborne irritants, cold air, parasympathetic stimulation, histamine
– Bronchodilation (increase airflow)• sympathetic nerves, epinephrine
![Page 24: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/24.jpg)
22-24
Alveolar Surface Tension
• Thin film of water needed for gas exchange– creates surface tension that acts to collapse
alveoli and distal bronchioles
• Pulmonary surfactant (great alveolar cells)
– decreases surface tension
• Premature infants that lack surfactant suffer from respiratory distress syndrome
![Page 25: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/25.jpg)
22-25
Alveolar Ventilation• Dead air
– fills conducting division of airway, cannot exchange gases
• Anatomic dead space– conducting division of airway
• Physiologic dead space– sum of anatomic dead space and any
pathological alveolar dead space
• Alveolar ventilation rate– air that ventilates alveoli X respiratory rate– directly relevant to ability to exchange gases
![Page 26: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/26.jpg)
22-26
Measurements of Ventilation
• Spirometer - measures ventilation
• Respiratory volumes– tidal volume: volume of air in one quiet breath– inspiratory reserve volume
• air in excess of tidal inspiration that can be inhaled with maximum effort
– expiratory reserve volume• air in excess of tidal expiration that can be exhaled
with maximum effort
– residual volume (keeps alveoli inflated)
• air remaining in lungs after maximum expiration
![Page 27: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/27.jpg)
22-27
Lung Volumes and Capacities
![Page 28: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/28.jpg)
22-28
• Vital capacity– total amount of air that can be exhaled with
effort after maximum inspiration• assesses strength of thoracic muscles and
pulmonary function
• Inspiratory capacity– maximum amount of air that can be inhaled
after a normal tidal expiration
• Functional residual capacity– amount of air in lungs after a normal tidal
expiration
Respiratory Capacities
![Page 29: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/29.jpg)
22-29
Respiratory Capacities
• Total lung capacity– maximum amount of air lungs can hold
• Forced expiratory volume (FEV)– % of vital capacity exhaled/ time– healthy adult - 75 to 85% in 1 sec
• Peak flow– maximum speed of exhalation
• Minute respiratory volume (MRV)– TV x respiratory rate, at rest 500 x 12 = 6 L/min– maximum: 125 to 170 L/min
![Page 30: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/30.jpg)
22-30
Respiratory Volumes and Capacities
• Age - lung compliance, respiratory muscles weaken
• Restrictive disorders compliance and vital capacity (limit amt
lungs can be inflated)
• Obstructive disorders– interfere with airflow by narrowing or blocking
the airway
![Page 31: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/31.jpg)
22-31
Composition of Air• Dalton’s Law: total atmospheric pressure is a sum of the
contributions of the individual gases
• Mixture of gases; each contributes its partial pressure– at sea level 1 atm. of pressure = 760 mmHg– nitrogen constitutes 78.6% of the atmosphere so
• PN2 = 78.6% x 760 mmHg = 597 mmHg
• PO2 = 159
• PH2O = 3.7
• PCO2 = + 0.3
• PN2 + PO
2 + PH2O + PCO
2 = 760 mmHg
![Page 32: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/32.jpg)
22-32
Composition of Air
• Partial pressures (as well as solubility of gas)
– determine rate of diffusion of each gas and gas exchange between blood and alveolus
• Alveolar air– humidified, exchanges gases with blood, mixes with
residual air – contains:
• PN2 = 569
• PO2 = 104
• PH2O = 47
• PCO2 = 40 mmHg
![Page 33: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/33.jpg)
22-33
Air-Water Interface
• Important for gas exchange between air in lungs and blood in capillaries
• Gases diffuse down their concentration gradients
• Henry’s law– amount of gas that dissolves in water is
determined by its solubility in water and its partial pressure in air
![Page 34: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/34.jpg)
22-34
Alveolar Gas Exchange
![Page 35: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/35.jpg)
22-35
Alveolar Gas Exchange
• Time required for gases to equilibrate = 0.25 sec
• RBC transit time at rest = 0.75 sec to pass through alveolar capillary
• RBC transit time with vigorous exercise = 0.3 sec
![Page 36: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/36.jpg)
22-36
Factors Affecting Gas Exchange• Concentration gradients of gases
– PO2 = 104 in alveolar air versus 40 in blood
– PCO2 = 46 in blood arriving versus 40 in alveolar
air
• Gas solubility– CO2 20 times as soluble as O2
• O2 has conc. gradient, CO2 has solubility
![Page 37: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/37.jpg)
22-37
Factors Affecting Gas Exchange• Membrane thickness - only 0.5 m thick
• Membrane surface area - 100 ml blood in alveolar capillaries, spread over 70 m2
• Ventilation-perfusion coupling - areas of good ventilation need good perfusion (vasodilation)
![Page 38: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/38.jpg)
22-38
Concentration Gradients of Gases
![Page 39: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/39.jpg)
22-39
Ambient Pressure and Concentration Gradients
![Page 40: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/40.jpg)
22-40
Lung Disease Affects Gas Exchange
![Page 41: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/41.jpg)
22-41
Perfusion Adjustments
![Page 42: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/42.jpg)
22-42
Ventilation Adjustments
![Page 43: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/43.jpg)
22-43
Oxygen Transport
• Concentration in arterial blood– 20 ml/dl
• 98.5% bound to hemoglobin• 1.5% dissolved
• Binding to hemoglobin– each heme group of 4 globin chains may
bind O2
– oxyhemoglobin (HbO2 )
– deoxyhemoglobin (HHb)
![Page 44: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/44.jpg)
22-44
Oxygen Transport
• Oxyhemoglobin dissociation curve– relationship between hemoglobin saturation
and PO2 is not a simple linear one
– after binding with O2, hemoglobin changes
shape to facilitate further uptake (positive
feedback cycle)
![Page 45: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/45.jpg)
22-45
Oxyhemoglobin Dissociation Curve
![Page 46: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/46.jpg)
22-46
Carbon Dioxide Transport
• As carbonic acid - 90%– CO2 + H2O H2CO3 HCO3
- + H+
• As carbaminohemoglobin (HbCO2)- 5% binds to amino groups of Hb (and plasma proteins)
• As dissolved gas - 5%
• Alveolar exchange of CO2
– carbonic acid - 70% – carbaminohemoglobin - 23%– dissolved gas - 7%
![Page 47: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/47.jpg)
22-47
Systemic Gas Exchange• CO2 loading
– carbonic anhydrase in RBC catalyzes• CO2 + H2O H2CO3 HCO3
- + H+
– chloride shift• keeps reaction proceeding, exchanges HCO3
-
for Cl- (H+ binds to hemoglobin)
• O2 unloading– H+ binding to HbO2 its affinity for O2
• Hb arrives 97% saturated, leaves 75% saturated - venous reserve
– utilization coefficient • amount of oxygen Hb has released 22%
![Page 48: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/48.jpg)
22-48
Systemic Gas Exchange
![Page 49: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/49.jpg)
22-49
Alveolar Gas Exchange Revisited
• Reactions are reverse of systemic gas exchange
• CO2 unloading
– as Hb loads O2 its affinity for H+ decreases, H+ dissociates from Hb and bind with HCO3
-
• CO2 + H2O H2CO3 HCO3- + H+
– reverse chloride shift
• HCO3- diffuses back into RBC in exchange
for Cl-, free CO2 generated diffuses into alveolus to be exhaled
![Page 50: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/50.jpg)
22-50
Alveolar Gas Exchange
![Page 51: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/51.jpg)
22-51
Factors Affect O2 Unloading
• Active tissues need oxygen!
– ambient PO2: active tissue has PO
2 ; O2 is
released
– temperature: active tissue has temp; O2 is
released
– Bohr effect: active tissue has CO2, which
lowers pH O2 is released
![Page 52: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/52.jpg)
22-52
Oxygen Dissociation and Temperature
![Page 53: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/53.jpg)
22-53
Oxygen Dissociation and pH
Bohr effect: release of O2 in response to low pH
![Page 54: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/54.jpg)
22-54
• Haldane effect– low level of HbO2 (as in active tissue) enables
blood to transport more CO2
– HbO2 does not bind CO2 as well as deoxyhemoglobin (HHb)
– HHb binds more H+ than HbO2
• as H+ is removed this shifts the
CO2 + H2O HCO3- + H+
reaction to the right
Factors Affecting CO2 Loading
![Page 55: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/55.jpg)
22-55
Blood Chemistry and Respiratory Rhythm
• Rate and depth of breathing adjusted to maintain levels of:– pH
– PCO2
– PO2
• Let’s look at their effects on respiration:
![Page 56: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/56.jpg)
22-56
Effects of Hydrogen Ions
• pH of CSF (most powerful respiratory stimulus)
• Respiratory acidosis (pH < 7.35) caused by failure of pulmonary ventilation
– hypercapnia: PCO2 > 43 mmHg
• CO2 easily crosses blood-brain barrier
• in CSF the CO2 reacts with water and releases H+
• central chemoreceptors strongly stimulate inspiratory center
– “blowing off ” CO2 pushes reaction to the left CO2 (expired) + H2O H2CO3 HCO3
- + H+
– so hyperventilation reduces H+ (reduces acid)
![Page 57: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/57.jpg)
22-57
Effects of Hydrogen Ions
• Respiratory alkalosis (pH > 7.45)
– hypocapnia: PCO2 < 37 mmHg
– Hypoventilation ( CO2), pushes reaction to the right CO2 + H2O H2CO3 HCO3
- + H+
H+ (increases acid), lowers pH to normal
• pH imbalances can have metabolic causes– uncontrolled diabetes mellitus
• fat oxidation causes ketoacidosis, may be compensated for by Kussmaul respiration
(deep rapid breathing)
![Page 58: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/58.jpg)
22-58
Effects of Carbon Dioxide
• Indirect effects on respiration– through pH as seen previously
• Direct effects CO2 may directly stimulate peripheral
chemoreceptors and trigger ventilation more quickly than central chemoreceptors
![Page 59: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/59.jpg)
22-59
Effects of Oxygen
• Usually little effect
• Chronic hypoxemia, PO2 < 60 mmHg,
can significantly stimulate ventilation– emphysema, pneumonia– high altitudes after several days
![Page 60: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/60.jpg)
22-60
Hypoxia
• Causes:– hypoxemic hypoxia - usually due to inadequate
pulmonary gas exchange• high altitudes, drowning, aspiration, respiratory
arrest, degenerative lung diseases, CO poisoning
– ischemic hypoxia - inadequate circulation– anemic hypoxia - anemia– histotoxic hypoxia - metabolic poison (cyanide)
• Signs: cyanosis - blueness of skin
• Primary effect: tissue necrosis, organs with high metabolic demands affected first
![Page 61: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/61.jpg)
22-61
Oxygen Excess
• Oxygen toxicity: pure O2 breathed at 2.5 atm or greater– generates free radicals and H2O2
– destroys enzymes– damages nervous tissue– leads to seizures, coma, death
• Hyperbaric oxygen– formerly used to treat premature infants,
caused retinal damage, discontinued
![Page 62: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/62.jpg)
22-62
Chronic Obstructive Pulmonary Disease
• Asthma– allergen triggers histamine release– intense bronchoconstriction (blocks air flow)
• Other COPD’s usually associated with smoking
– chronic bronchitis – emphysema
![Page 63: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/63.jpg)
22-63
Chronic Obstructive Pulmonary Disease
• Chronic bronchitis – cilia immobilized and in number– goblet cells enlarge and produce excess
mucus– sputum formed (mucus and cellular debris)
• ideal growth media for bacteria
– leads to chronic infection and bronchial inflammation
![Page 64: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/64.jpg)
22-64
Chronic Obstructive Pulmonary Disease
• Emphysema (barrel chest)– alveolar walls break down
• much less respiratory membrane for gas exchange– healthy lungs are like a sponge; in emphysema, lungs are
more like a rigid balloon
– lungs fibrotic and less elastic– air passages collapse
• obstruct outflow of air• air trapped in lungs
![Page 65: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/65.jpg)
22-65
Effects of COPD
pulmonary compliance and vital capacity
• Hypoxemia, hypercapnia, respiratory acidosis– hypoxemia stimulates erythropoietin release
and leads to polycythemia
• cor pulmonale – hypertrophy and potential failure of right heart
due to obstruction of pulmonary circulation
![Page 66: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/66.jpg)
22-66
Smoking and Lung Cancer
• Lung cancer accounts for more deaths than any other form of cancer– most important cause is smoking (15
carcinogens)
• Squamous-cell carcinoma (most common)– begins with transformation of bronchial
epithelium into stratified squamous– dividing cells invade bronchial wall, cause
bleeding lesions– dense swirls of keratin replace functional
respiratory tissue
![Page 67: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/67.jpg)
22-67
Lung Cancer
• Adenocarcinoma – originates in mucous glands of lamina propria
• Small-cell (oat cell) carcinoma– least common, most dangerous– originates in primary bronchi, invades
mediastinum, metastasizes quickly
![Page 68: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/68.jpg)
22-68
Progression of Lung Cancer
• 90% originate in primary bronchi
• Tumor invades bronchial wall, compresses airway; may cause atelectasis
• Often first sign is coughing up blood
• Metastasis is rapid; usually occurs by time of diagnosis– common sites: pericardium, heart, bones, liver,
lymph nodes and brain
• Prognosis poor after diagnosis– only 7% of patients survive 5 years
![Page 69: 22-1 Chapter 22 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright (c) The McGraw-Hill](https://reader030.vdocuments.us/reader030/viewer/2022032802/56649e1a5503460f94b07cb9/html5/thumbnails/69.jpg)
22-69
Healthy Lung/Smokers Lung- Carcinoma