The document discusses lung elastance, compliance, and work of breathing. It defines key terms like elastance, compliance, and surface tension. It describes the elastance of the thoracic cage and lungs, the role of pulmonary surfactant in reducing surface tension, and how compliance is measured. It also explains the different components of work of breathing, including overcoming elastic, viscous, and airway resistance, and how work of breathing is affected in restrictive and obstructive lung diseases.
Gas exchange between the alveoli and the pulmonary capillary blood occurs by diffusion, as will be discussed in the next chapter. Diffusion of oxygen and carbon dioxide occurs passively, according to their concentration differences across the alveolar-capillary barrier. These concentration differences must be maintained by ventilation of the alveoli and perfusion of the pulmonary capillaries.
Alveolar ventilation brings oxygen into the lung and removes carbon dioxide from it. Similarly, the mixed venous blood brings carbon dioxide into the lung and takes up alveolar oxygen. The alveolar Image not available. and Image not available. are thus determined by the relationship between alveolar ventilation and pulmonary capillary perfusion. Alterations in the ratio of ventilation to perfusion, called the Image not available., will result in changes in the alveolar Image not available. and Image not available., as well as in gas delivery to or removal from the lung.
Alveolar ventilation is normally about 4 to 6 L/min and pulmonary blood flow (which is equal to cardiac output) has a similar range, and so the Image not available. for the whole lung is in the range of 0.8 to 1.2. Image not available. However, ventilation and perfusion must be matched on the alveolar-capillary level, and the Image not available. for the whole lung is really of interest only as an approximation of the situation in all the alveolar-capillary units of the lung. For instance, suppose that all 5 L/min of the cardiac output went to the left lung and all 5 L/min of alveolar ventilation went to the right lung. The whole lung Image not available. would be 1.0, but there would be no gas exchange because there could be no gas diffusion between the ventilated alveoli and the perfused pulmonary capillaries.
Oxygen is delivered to the alveolus by alveolar ventilation, is removed from the alveolus as it diffuses into the pulmonary capillary blood, and is carried away by blood flow. Similarly, carbon dioxide is delivered to the alveolus in the mixed venous blood and diffuses into the alveolus in the pulmonary capillary. The carbon dioxide is removed from the alveolus by alveolar ventilation. As will be discussed in Chapter 6, at resting cardiac outputs the diffusion of both oxygen and carbon dioxide is normally limited by pulmonary perfusion. Thus, the alveolar partial pressures of both oxygen and carbon dioxide are determined by the Image not available. If the Image not available. in an alveolar-capillary unit increases, the delivery of oxygen relative to its removal will increase, as will the removal ...
Ventilation perfusion ratio (The guyton and hall physiology)Maryam Fida
Ventilation perfusion ratio is :
“The ratio of alveolar ventilation and the amount of blood that perfuse the alveoli”.
FORMULA
It is expressed as VA/Q.
VA is alveolar ventilation
Q is the blood flow (perfusion)
Normal value of ventilation perfusion ratio is about
0.8
VA is 4.2 L /min
Q is 5.5 L/min (Same as Cardiac output)
So VA/Q = 4.2/5.5 = 0.8
If VA becomes zero ratio becomes zero
If Q becomes zero ratio becomes infinite.
If ratio becomes zero or infinite then there is no gaseous exchange. So this ratio indicates the efficiency of gaseous exchange in lungs.
In standing or sitting position this ratio is not uniform in all parts of the lungs.
In standing position, in upper parts of lungs there is almost no blood flow so normally in upper parts of lungs the ratio is higher may be near 3.
In lower part of lungs, there is more blood flow so the ratio is decreased may be 0.6.
In certain diseases the VA/Q ratio is higher which means perfusion is inadequate i.e. in some parts of lungs the alveoli are non functional or partially functional. This is seen in cases of pulmonary thrombosis or embolism.
When there is higher VA/Q ratio, PO2 and PCO2 in the alveolar air resembles the values in the inspired air.
When exchange is not occurring because of lack of perfusion, inspired air goes to alveoli, as there is no exchange occurring so the same values of PCO2 and PO2 as in inspired air.
Gas exchange between the alveoli and the pulmonary capillary blood occurs by diffusion, as will be discussed in the next chapter. Diffusion of oxygen and carbon dioxide occurs passively, according to their concentration differences across the alveolar-capillary barrier. These concentration differences must be maintained by ventilation of the alveoli and perfusion of the pulmonary capillaries.
Alveolar ventilation brings oxygen into the lung and removes carbon dioxide from it. Similarly, the mixed venous blood brings carbon dioxide into the lung and takes up alveolar oxygen. The alveolar Image not available. and Image not available. are thus determined by the relationship between alveolar ventilation and pulmonary capillary perfusion. Alterations in the ratio of ventilation to perfusion, called the Image not available., will result in changes in the alveolar Image not available. and Image not available., as well as in gas delivery to or removal from the lung.
Alveolar ventilation is normally about 4 to 6 L/min and pulmonary blood flow (which is equal to cardiac output) has a similar range, and so the Image not available. for the whole lung is in the range of 0.8 to 1.2. Image not available. However, ventilation and perfusion must be matched on the alveolar-capillary level, and the Image not available. for the whole lung is really of interest only as an approximation of the situation in all the alveolar-capillary units of the lung. For instance, suppose that all 5 L/min of the cardiac output went to the left lung and all 5 L/min of alveolar ventilation went to the right lung. The whole lung Image not available. would be 1.0, but there would be no gas exchange because there could be no gas diffusion between the ventilated alveoli and the perfused pulmonary capillaries.
Oxygen is delivered to the alveolus by alveolar ventilation, is removed from the alveolus as it diffuses into the pulmonary capillary blood, and is carried away by blood flow. Similarly, carbon dioxide is delivered to the alveolus in the mixed venous blood and diffuses into the alveolus in the pulmonary capillary. The carbon dioxide is removed from the alveolus by alveolar ventilation. As will be discussed in Chapter 6, at resting cardiac outputs the diffusion of both oxygen and carbon dioxide is normally limited by pulmonary perfusion. Thus, the alveolar partial pressures of both oxygen and carbon dioxide are determined by the Image not available. If the Image not available. in an alveolar-capillary unit increases, the delivery of oxygen relative to its removal will increase, as will the removal ...
Ventilation perfusion ratio (The guyton and hall physiology)Maryam Fida
Ventilation perfusion ratio is :
“The ratio of alveolar ventilation and the amount of blood that perfuse the alveoli”.
FORMULA
It is expressed as VA/Q.
VA is alveolar ventilation
Q is the blood flow (perfusion)
Normal value of ventilation perfusion ratio is about
0.8
VA is 4.2 L /min
Q is 5.5 L/min (Same as Cardiac output)
So VA/Q = 4.2/5.5 = 0.8
If VA becomes zero ratio becomes zero
If Q becomes zero ratio becomes infinite.
If ratio becomes zero or infinite then there is no gaseous exchange. So this ratio indicates the efficiency of gaseous exchange in lungs.
In standing or sitting position this ratio is not uniform in all parts of the lungs.
In standing position, in upper parts of lungs there is almost no blood flow so normally in upper parts of lungs the ratio is higher may be near 3.
In lower part of lungs, there is more blood flow so the ratio is decreased may be 0.6.
In certain diseases the VA/Q ratio is higher which means perfusion is inadequate i.e. in some parts of lungs the alveoli are non functional or partially functional. This is seen in cases of pulmonary thrombosis or embolism.
When there is higher VA/Q ratio, PO2 and PCO2 in the alveolar air resembles the values in the inspired air.
When exchange is not occurring because of lack of perfusion, inspired air goes to alveoli, as there is no exchange occurring so the same values of PCO2 and PO2 as in inspired air.
Ventilation and Perfusion in different zones of lungs.Gyaltsen Gurung
This powerpoint presentation will make you explore about the Perfusion and Ventilation in different zones of lungs with its co-relation with pulmonary tuberculosis.
The apparatus used to measure
Volume of air exchanged during breathing
Respiratory rate
The record is called a spirogram
Upward deflection inhalation
Downward deflection exhalation
A brief overview of the physiology of the neuromuscular junction.It includes a video towards the end sourced from the internet with the copyright watermarks intact.
Outline the various factors affecting airway resistance and correlate it to changes in pulmonary ventilation.
Describe the metabolism of surfactant, discuss its significance and relate its deficiency to clinical conditions.
Define compliance of the lung and chest wall, illustrate and discuss the compliance curve and describe the effect of surfactant on it.
Discuss work of breathing and relate it to clinical conditions.
Ventilation and Perfusion in different zones of lungs.Gyaltsen Gurung
This powerpoint presentation will make you explore about the Perfusion and Ventilation in different zones of lungs with its co-relation with pulmonary tuberculosis.
The apparatus used to measure
Volume of air exchanged during breathing
Respiratory rate
The record is called a spirogram
Upward deflection inhalation
Downward deflection exhalation
A brief overview of the physiology of the neuromuscular junction.It includes a video towards the end sourced from the internet with the copyright watermarks intact.
Outline the various factors affecting airway resistance and correlate it to changes in pulmonary ventilation.
Describe the metabolism of surfactant, discuss its significance and relate its deficiency to clinical conditions.
Define compliance of the lung and chest wall, illustrate and discuss the compliance curve and describe the effect of surfactant on it.
Discuss work of breathing and relate it to clinical conditions.
Respiratory physiology is a branch of physiology that studies the mechanics, chemistry, and control of respiration. Respiration is the process by which an organism exchanges gases with its environment. In humans, respiration is the process by which we take in oxygen from the air and release carbon dioxide back into the air.
The mechanics of respiration are the processes by which air is moved into and out of the lungs. This is done by the muscles of the respiratory system, which include the diaphragm, the intercostal muscles, and the muscles of the larynx. The details of how the respiratory system carries out its functions are covered in this course.
The main objective of this course is that readers should:
1. Know the meaning of respiration
2. Be able to explain how the intrapulmonary and intrapleural pressures vary during ventilation and relate these pressure changes to Boyle's law.
3. Be able to define the terms compliance and elasticity and explain how these lung properties affect ventilation.
4. Be able to discuss the significance of surface tension in lung mechanics, explain how the law of Laplace applies to lung function, and describe the role of pulmonary surfactant.
5. Be able to know the pulmonary function tests and their importance. e.t.c.
The biomechanical properties of connective tissues are critical determinants of how mechanical forces acting on the body/organ produce physical changes at the cellular level.
The Biomechanical properties of lung are discussed
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
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Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
2. OBJECTIVES.
Pulmonary Elastance
Elastance of thoracic cage
Elastance of Lungs
Alveolar surface tension
Pulmonary surfactant
Pulmonary Compliance
Def, NR
Measurement
Static Vs Specific
Work of breathing
3. PULMONARY ELASTANCE
Elastance –
Def – recoil of Retractive tendency of any structure.
Elastance of Thoracic cage
Elastance of lungs
Friday, May 14, 2021
4. ELASTANCE OF THORACIC CAGE
Constant tendency of thoracic cage to expand
which is normally kept partially pulled inward.
It is because of the elastic nature of ribs, muscles
and tendons.
Friday, May 14, 2021
5. ELASTANCE OF LUNGS
Constant tendency of lungs to collapse
Tissue forces
Presence of many elastic tissues such as smooth
muscle, elastic and collagen in the lung parenchyma
Surface forces – alveolar surface tension.
Friday, May 14, 2021
6. ALVEOLAR SURFACE TENSION
Surface of alveolar
membrane lined by liquid
Unbalance attraction of
liquid molecules at surface
creates surface tension --
Vander wall forces.
Surface tension increases
the tendency of the lungs
to deflate/collapse.
Friday, May 14, 2021
7. Law of laplace
P=2T/r
Therefore, small alveoli
tend to become still smaller
whereas large alveoli tend
to become still larger
Friday, May 14, 2021
8. PULMONARY SURFACTANT
Source – type II alveolar epithelial
cells(granular pneumocytes).
Composition – DPPC (Dipalmitoyl-
phosphatidylcholine)
Mechanism of action
Hydrophilic portion
Hydrophobic portion
Friday, May 14, 2021
9. Mechanism of action.
Hydrophilic portion
Hydrophobic portion
This causes spreading of surfactant molecules
over the surface of fluid lining the alveoli.
Apoproteins and calcium ions are responsible
for uniform and quick spreading of surfactant
molecules over the surface.
Friday, May 14, 2021
10. Functions
The tendency of alveoli to collapse
Work of breathing
Prevents pulmonary oedema Pulls fluid from the
capillaries into the interstitial space surrounding the
alveoli and into the alveoli leading to pulmonary oedema.
Alveolar stabilization.
Pulling pressure 18 cm of H2O
4 cm of H2O
Friday, May 14, 2021
11. MECHANISM OF ALVEOLAR
STABILIZATION
In the presence of
surfactant
ST = 1/ Surfactant.
Other factors
Interdependence of
alveolar septa
Fibrous tissue.
Friday, May 14, 2021
12. Factors affecting pulmonary
surfactant
.
• Long term inhalation
of 100% O2
.
• Occlusion
• Main bronchus
• Pulmonary artery.
.
• Cigarate smoking.
• Cutting vagi.
Friday, May 14, 2021
• Thyroid hormones
. • Glucocorticoids
.
15. Definition & Normal value
C= δV/ δ P
Transpulmonary pressure = alveolar
pressure – pleural pressure.
Normal value
Both 0.13L/cm of H2O
Lung alone 0.22 L/cm of H2O
Friday, May 14, 2021
18. FACTORS AFFECTING COMPLIANCE
Elastic forces of the
lung tissue – mainly
due to elastic &
collagen fibres (1/3rd)
Elastic forces caused
by surface tension
(2/3rd)
Friday, May 14, 2021
19. Static vs Specific Lung
Compliance
Static compliance
Depend upon size
Amount of functional
lung tissue.
Specific lung
compliance
Compliance of the lung
at relaxation volume
i.e. at the end of tidal
expiration
FRC.
Friday, May 14, 2021
20. LUNG COMPLIANCE CHANGES
• Emphysema
• Ageing process
• .
Friday, May 14, 2021
• Lung diseases (TB,
Silicosis)
• Destruction of
functional lung tissue.
• RLD
21. Work of breathing
Contraction of respiratory
muscles.
Expansion of thoracic cage
& Lungs
Decreases intra alveolar
pressure & push air inside
Friday, May 14, 2021
24. AIRWAY RESISTANCE
Friction of gas molecules and wall of airways.
Factors affecting
Rate of gas flow
Airway radius. Poiseuille-Hagen formula
Resistance α 1/r4
Length of airway
Type of airflow
Friday, May 14, 2021
25. CONTROL OF AIRWAY DIAMETER
Sympathetic adrenergic – Bronchodilataion
Vagus – bronchoconstriction & Mucous
formation.
Friday, May 14, 2021
26. COMPONENTS OF WORK OF
BREATHING
Work done to overcome
Elastic resistance (65%)
Viscous resistance (7%)
Airway resistance (28%)
Friday, May 14, 2021
27. CALCULATION OF WORK OF
BREATHING
Work done during inspiration
Work done during Expiration
Friday, May 14, 2021
28. WORK DONE DURING
INSPIRATION
Compliance work refers to
the work done by respiratory
muscles to inflate the lungs
against the elastic resistance
of chest wall and lungs.
It is represented by the
triangular area Thus most of
the work done (65%) is used
to overcome elastic
resistance.
Friday, May 14, 2021
29. Non-elastic resistance work
Work is done to overcome the nonelastic
resistance.
It includes the work done to overcome:
Viscous resistance of lungs (7%) and
Airway resistance (28%).
Friday, May 14, 2021
30. WORK DONE DURING
EXPIRATION
Since in quiet breathing,
expiration is a passive
process so no work is done
during expiration.
When the lungs are recoiling
back some energy is required
to overcome non-elastic
resistance, i.e. the airway
resistance plus viscous tissue
resistance.
Friday, May 14, 2021
33. APPLIED
Work of breathing in
Restrictive lung diseases
Obstructive lung diseases.
Friday, May 14, 2021
34. FACTORS AFFECTING TOTAL WORK
OF BREATHING.
Total work of breathing in quiet respiration
0.3-0.8 kg mt/min.
Increases
As resistance increases
Muscular exercise.
Friday, May 14, 2021
35. Objectives seen……
Pulmonary Elastance
Elastance of thoracic cage
Elastance of Lungs
Alveolar surface tension
Pulmonary surfactant
Pulmonary Compliance
Def, NR
Measurement
Static Vs Specific
Work of breathing
Friday, May 14, 2021