Respiratory Physiology Quiz

Respiratory Physiology

• Respiratory physiology is the study of how the respiratory system works to provide oxygen and remove carbon dioxide from the body.
• The process starts at the mouth and ends at the mitochondria.
• This system involves many parts and their interconnections in a complex pathway.

Outline

• The outline of the respiratory system pathway of oxygen includes:
  • Anatomy & Histology of the Respiratory System
  • Physiology
  • Measurements in clinical practice
  • Linking disease, measurements and clinical history

Cardiovascular & Respiratory Interactions

• Interactions between the cardiovascular and respiratory systems impact rest, sleep, and exercise.
• Central and Autonomic controls are involved in these interactions.
• Mechanisms that control blood flow, gas exchange, and transport are complex and dynamic.

Model of the Mammalian Respiratory System

• The model of the mammalian respiratory system illustrates air and oxygen flow through various lung components, including:
  • ventilation (convective)
  • cardiac output
  • metabolic and molecular processes.
  • Components of the respiratory system: Parts of the airways: trachea, bronchi, bronchioles, alveolar ducts, and alveoli

Global Interactions

• Cardiovascular and ventilatory systems must be coupled efficiently.
• This reduces stress and supports energy transformations.
• Interaction between physiological mechanisms links gas exchange.

The Upper Airway

• Describes structures and their components such as: Nares, Hard and Soft Palate, Oral Cavity, Tongue, Larynx, Thyroid Cartilage, Cricoid Cartilage, Nasopharynx, Uvula, Oropharynx, Epiglottis, Trachea and Oesophagus.

Rib Cage

• Explains structures and their components for the rib cage, including: Clavicle, Sternal Angle, Sternum ,Xiphoid and Costal Cartilages, True Ribs (1–7), False Ribs (8–12).

What's Inside the Chest?

• Provides radiological imaging of the chest and structures inside, such as: Clavicle, Aortic Arch, Trachea, Upper, Middle, and Lower Lungs, Carina, Diaphragm, Stomach, Liver and Heart.

Airways

• Classifies the airways' structure into conducting and respiratory zones.
• The conducting zone includes Trachea, Bronchi, Bronchioles, with multiple levels of branching from trachea down to alveoli.
• The respiratory zone includes Respiratory Bronchioles, Alveolar Ducts, and Alveolar Sacs.

Major Airway Histology

• Trachea
• Respiratory Bronchioles
• Alveolus'
• Pulmonary capillary
• Alveolar capillary membrane

Airway Surface

• Describes Structures of the Airway Surface, with information on: Mucous layer, Goblet cells, and Cilia.

Alveoli

• Provides anatomical information on the alveolus structure.

Circulation

• Describes general blood circulation relevant to respiratory physiology.

Pulmonary Circulation

• Details the parts of the Pulmonary Circulation pathway including the Pulmonary Artery, Pulmonary Capillaries, Pulmonary Circuit, and Pulmonary Vein.
• Includes measurements such as alveolar surface area, capillary surface area, capillary volume (rest and max) associated with Pulmonary circulation.

Systemic Circulation

• Summarizes the blood circulation parts associated with the systemic circulation, including: the heart, lungs, and various other body parts like the muscles, liver, kidneys, brain, skin, etc with comparative volume measurements at rest vs. exercise. (e.g., muscles - 20% resting, 84% exercising)

Cellular Respiration - Mitochondria

• Describes the process of cellular respiration as well as the role of mitochondria in cells (i.e., ATP production).
• Details the use of Oxygen as a reactant in mitochondrial respiration.
• Explains how different cells have varied number of mitochondria.

Summary

• The respiratory system starts at the mouth and ends at the mitochondria (the process in the pathway of oxygen).
• Understanding the anatomy and histology are essential for understanding gas exchange and its impact in diseases.

Mechanics of Ventilation

• Explains the mechanics of breathing (ventilation).
• Diagrams illustrate the concept of breathing in and breathing out.

Static Lung Volumes

• Describes static lung volumes, including: Total Lung Capacity, Inspiratory Reserve Volume, Vital Capacity, Inspiratory Capacity, Tidal Volume, Expiratory Reserve Volume, Residual Volume and Functional Residual Capacity.

Simple Model

• An illustration of the chest wall, pleural space and lung and their alveoli along with diagrams of a X-ray picture of a chest.

Compliance

• Describes how lung volume changes as a function of transpulmonary pressure.
• Shows differences between compliant vs. noncompliant lungs based on curves.

The Respiratory Cycle

• Presents step-by-step diagrams of the cyclical changes in pressure and volumes.

Respiratory Muscles

• Respiratory muscles have no inherent rhythm, and generate tension due to neuron-induced actions, so they can overcome airflow resistance.
• The thorax is positioned at Functional Residual Capacity (FRC) at rest, and assumes this position.

Muscles of Inspiration and Expiration

• Shows and describes the structural components of the muscles used for inspiration (e.g. sternocleidomastoid, scalenes, serratus anterior, external intercostals, diaphragm ) and expiration (e.g., internal intercostals, transverse thoracis, external oblique and internal oblique, rectus abdominis).

Diaphragm

• Details the functions of the diaphragm, including ventilation, support for coughing, sneezing, singing and instruments, along with its important role in constipation situations.

Diaphragm & Sleep

• Discusses the diaphragm's function during sleep, notably during REM sleep, and describes how ventilation may become erratic in some cases.
• Discusses the issue of Oxygen desaturation as a possible consequence of erratic ventilation during sleep.

Summary

• Respiratory muscles are crucial for respiration, with activity varying.
• The diaphragm is the primary muscle and damages to these muscles, or their nerve supply will negatively impact respiratory function.

Airflow

• Introduces the concept of airflow in the respiratory system.

Flow Characteristics

• Illustrates the laminar, turbulent and transitional types of airflow as a function of pressure.

Airways Resistance

• Describes the resistance in the conducting zone and respiratory zone as a function of airway generation.

Factors Affecting Airways Resistance

• Discusses factors affecting airway resistance, including: Airway length, Radius of airways, Lung volume, Elastic recoil, Bronchomotor tone.

Flow-Volume-Time Relationships

• Details flow-volume-time relationships, including: FVC, FEV1, and PEF for normal vs. airflow obstruction and restrictive ventilatory defects.

Flow Limitation

• Illustrates diagrammatically the flow limitation concept (i.e., different parts of the respiratory system potentially acting as a limit to airflow).

Gas Exchange

• Explains the principle concepts of gas exchange in the lungs

Alveolar Gas Exchange

• Explains the process of gas exchange at the alveolar level

Successful Gas Exchange

• Lungs must be ventilated and perfused, and ventilation and perfusion must be well matched for effective gas exchange.

Transport of Oxygen

• Presents the different pathways of oxygen from inspiration, alveolar ventilation, to cellular uptake.
• Presents the role of arterial and venous mixtures, V/Q ratios and haemoglobin concentration in this pathway.

Diffusion of Oxygen

• Shows how oxygen diffusion is a function of time spent in capillary transit.

Transport of Carbon Dioxide (CO2)

• Describes the transport pathways for carbon dioxide, including: Alveolar ventilation, dead space, alveolar PCO2, barometric pressure, V/Q Ratios, and Shunts.

Diffusion of Carbon Dioxide

• Shows how carbon dioxide diffusion is a function of time spent in capillary transit.

Gas Transport in Blood

• Explains the concept of gas transport in blood, with hemoglobin playing a major role.

Haemoglobin – Its Task

• Details how the function of Haemoglobin works, including: large capacity for Oxygen transport, carrying oxygen, releasing oxygen and loading/unloading oxygen over the different ranges of oxygen pressures.
• Explains how its binding affinity alters with demands of oxygen

Transport of Oxygen

• Lists different four forms of oxygen storage in the body, in context of oxygen transport.

Oxygen and Haemoglobin

• Presents the oxygen and hemoglobin reaction equations.

Transport of Oxygen

• Explains how the concentration of bound oxygen and total oxygen is calculated.

Oxyhaemoglobin Dissociation Curve

• Illustrates the curve concept and relates it to systemic and pulmonary circulation.

Oxyhaemoglobin Dissociation Curve

• Shifts right in the curve as a response to changes in factors like Temperature, pH and CO2.

Oxyhaemoglobin Dissociation Curve

• Shifts left as a response to changes in factors like temperature, pH and CO2, along with 2-3 DPG.

Transport of Oxygen - anaemia

• Effect of anemia on bound oxygen concentration, as a function of different concentrations of Haemoglobin.

Transport of Carbon Dioxide (CO2)

• Describes the transport of carbon dioxide, including: physical solution of CO2, carbonic acid and bicarbonate ion.

Carbonic Acid (CA)

• Describes the carbonic acid reaction between CO2 and H2O.
• Indicates the speed of the reaction using carbonic anhydrase

Transport of Carbon Dioxide

• Explains how CO2 is transported in the form of bicarbonate ions and carbamino compounds. (using the concept of haemoglobin).

Transport of CO2 & O2

• Presents the overall process.

Ventilation-Perfusion Relationships

• Presents anatomical imaging of the lungs.

Three-Zone Model

• Describes the three-zone model and its components related to gas exchange and blood flow in the lungs.

V/Q Ratios in the Upright Lung

• Provides graphics and description of various V/Q ratios in the lungs based on height in the respiratory system

A Simple Model

• Presents a simplified theoretical model to illustrate gas exchange, includes various parameters (including CO2, O2, and pressure differences between the capillaries, alveoli and airways).

V/Q Scans – Normal & Severe COPD

• Presents graphics of VQ scans for normal vs. severe COPD.

Acid-Base Balance

• Explains the concept of acid-base balance and how the lungs and kidneys work to keep it consistent.

Basic Concepts

• Illustrates factors affecting acid-base balance in the body.
• Describes the body's systems that help in maintaining the acidity of bodily fluids.

Basic Concepts

• Details several chemical reactions and their roles in producing and absorbing protons.
• Indicates that lungs and kidneys act as fast response system for balancing the acidity/alkalinity values of the body.

pH

• Describes pH values, as related to acidity/alkalinity.
• Explains how to determine pH values, from hydrogen ion concentration.
• Graphical representations of pH values in relation to various physiological states.

Normal Values

• Presents various values and measurements considered as normal for physiological factors (e.g., pH values, H+ concentration, PaCO2, PaO2, HCO3 and SaO2.

The Body Buffer Systems

• Lists components (bicarbonate/carbonic acid, protein & phosphates) and their roles in maintaining the body's acid-base balance.

Basic Concepts, Metabolic Acidosis, Respiratory Alkalosis, Acute Respiratory Acidosis, Metabolic Alkalosis

• Describes the concept of various physiological states in contexts of metabolic acidosis, respiratory alkalosis etc, in relation to the pH values and the various chemical/physiological pathways involved. .

Clinical Acid-Base Disturbances

• Demonstrates the compensatory events that occur in response to various primary events. e.g. If PaCO2 increases, HCO3 concentration also increases, and viceversa.

Acid-Base Diagram

• Presents a graphical representation of acid-base disorders, in relation to blood acidity values.

Innervation of Respiratory Muscles and Airways

• Explains innervation of different components of the respiratory system.

Control of Respiration

• Explains respiration control mechanisms.
• Relates breathing pattern to involuntary control, and a regular rhythmic pattern.

Control of Respiration

• Lists 3 key functions required for adequate breathing pattern including: Maintaing adequate breathing rate and rhythm, adjusting tidal volume and respiratory frequency to meet demand, and adjusting breathing pattern to comply with other activities (e.g., speech).

Control of Respiration

• Under normal circumstances breathing is finely controlled. The system utilises pathways (PCO2, PO2) to maintain normal levels.
• Additional pathways are needed to accommodate additional activities such as speaking or swallowing.
• Two controllers influence this (i.e., metabolic and behavioral controllers).

Brainstem

• Illustrates diagrammatically central/peripheral chemoreceptors and indicates the role of various brainstem components in control of breathing and respiration.

Global Innervation

• Shows different nerve pathways that innervate (supply nerves to) the airways and muscles.

Central and Peripheral Chemoreceptors

• Presents a combination schematic diagrams of central/peripheral chemoreceptors and describes the functions, in relation to PaCO2 and PaO2, and H+.

Overall Control

• Shows how various systems (nervous system, sensory and emotional stimuli) influence breathing control (e.g. cortex in cerebral cortex, peripheral chemoreceptors).

Control of Breathing Pattern

• Presents the interrelation between different systems involved in breathing (influenced by chemcial/neurological components, motor nerves and muscles).
• Links breathing to chest, lungs and airways.

Mechanical Work of Breathing

• Discusses the importance, and how work of breathing is affected by the elastic and resistive parameters of the breathing pattern.

Gas Exchange and Breathing

• Describes how the relationship between VT and fB/frequency affects dead space ventilation.

Fundamental Stimulus

• Describes that tidal volume is controlled by PaCO2.
• Explains the rapid reaction time of the system to CO2 stimulus, and slower reaction time in response to oxygen stimulus.

Effects of Hypercapnia

• Discusses the effects of hypercapnia, from breathlessness to nausea, to loss of consciousness.
• Presents graphs describing ventilation responses as related to PaCO2.

Effects of Hypoxia

• Describes the physiological effects of hypoxia.
• Graphical presentations illustrating ventilation response as related to PaO2 and SaO2

Hypoxia in Normal Subject

• Shows a presentation of a normal subject undergoing a hypoxic stimulation challenge test.

Effects of Hypoxia

• Graphical presentation of ventilation vs. PaO2 (kPa), and ventilation vs. SaO2 (%)

Effect of Hypoxia

• Describes the physiological effects of hypoxia: increased ventilation, cardiac frequency, disorientation, loss of consciousness, and relationship of P02 with SaO2.

Hypoxic Challenge Test Response

• Pathway of hypoxic stimulus through various components of the pulmonary and respiratory systems, resulting in an increase in ventilation

Respiratory Function Tests

• Describes basic respiratory function tests - Spirometry, Lung volumes, Gas exchange, Skin tests, Exercise, Blood gases, including their uses, different stages (i.e., screening, intermediate and complex).

Children & Adults

• Shows that lung function testing is applicable to various age groups, with modifications required for pediatric testing.

Spirometry - This is the Practical Next Week

• Describes general uses of Spirometry.

Uses of Spirometry

• Provides baseline assessment of lung function, follows disease's course, measures inhalers, and assesses interventions.

Patterns of Spirometry

• Illustrates graphical representations of different patterns of spirometry (normal, airflow obstruction, restrictive ventilatory defect).

Respiratory Muscle Weakness

• Illustrates how respiratory muscle weakness can affect lung function tests.

Oximetry

• Describes uses for oximetry, often combined with spirometry as screening tool, and its relationship to patient assessment.

Pulse Oximeter Technology

• Shows the use and technology behind pulse oximeters.

Pulse Oximeter Technology

• Presents the absorption spectra concept involved in pulse oximeter measurements and provides visual representations of the principle.

Pulse Oximeter Technology

• Shows how pulsatile blood flow is detected and measurable with pulse oximetry.

Pulse Oximeter Technical Issues - Practical

• Shows some common practical issues encountered in the use of pulse oximeters.

Technical Limitations – Skin Pigmentation

• Shows limitations encountered in the applications of pulse-oximetry, specifically in situations with darker skin pigmentation.

Technical Limitations – Skin Pigmentation

• Demonstrates differences in extinction coefficients for various pigments as a result of pigmentation, and how they can potentially affect pulse oximeter readings.

Clinical Limitations

• Lists some common clinical limitations encountered in pulse oximetry measurements, including issues related to arterial oxyhemoglobin dissociation curve, skin perfusion and various other factors as related to arterial oxygen uptake and saturation.

Pulse Oximetry

• Presents general applications of pulse oximetry.

Summary

• Presents a summary of the respiratory system and its relationship to various parts of the body.
• Provides information related to clinical measurements, pathways, and physiological parameters to assess the effects of disease.
• Emphasizes the overall importance of respiration to the human body.