10. Respiratory System (14)

Volume of Air Remaining in Lungs after a Normal, Passive Tidal Expiration

Functional Residual Capacity (FRC)

When can FRC be greater than relaxation volume of a totally relaxed respiratory system?

If the Next Inhalation is Greater: than the Prior (Hyperinflation)

What does a reduction in surfactant result in?

Increased Surface Tension in Alveoli and Subsequent Increased Compression of Alveoli (Increased Surface Tension Recoil)

Maximal Volume of Air that can be Inspired During a Maximal Inspiratory Effort

Inspiratory Capacity

Maximal Volume of Air that can be Inhaled During a Maximal Forced Inspiration (Starts at the End of a Normal Inspiration)

Inspiratory Reserve Volume (IRV)

Elastic Recoil of Lungs and Alveolar-Associated Surface Tension

Inward force

Bone Abnormalities Lead to Reduced Movement of Thoracic Skeletal Components and Reduced Ability to Inhale Normally

Kyphoscoliosis

Can the total functional residual capacity be measured by spirometry?

No, because it contains residual volume

Can the total lung capacity be measured by spirometry?

No, because it contains residual volume

Excessive Amount of Adipose Tissue in Thoracic Region Impairs Breathing Movements

Obesity (Pickwickian Syndrome)

Disease Conditions in which Ability to Exhale is Affected

Obstructive disorders

Elastic Recoil of Chest Wall Musculature

Outward force

What are alveolar septa broken down by?

Proteolytic Enzymes of Leukocytes Attracted Locally by Macrophages

Production of Fiber-like Scar Tissue in Lung; Lung Tissues Become Stiff -Alveolar Tissue and Associated Capillaries Become Distorted

Pulmonary fibrosis

Composed of Two or More Lung Volumes

Pulmonary lung capacities

Functional Residual Capacity Lung Volume at this Point (End Expiration) may be Referred to as what?

Relaxation Volume or Resting Volume

Volume of Air Remaining in Lungs Following a Forced Maximal Expiration

Residual Volume (RV)

Volume of Gas Cannot be Exhaled Nor can it be Measured by Spirometry

Residual Volume (RV)

Disease Conditions in which Ability to Inhale is Affected

Restrictive Disorders

How do you directly measure tidal volume?

Spirometry

Change in Body Position from _____ or _____ to Supine Alters the FRC -What is this determined by?

Standing or Sitting -Static Compliance (Parameters)

What is the total lung capacity made up of?

Sum of All Lung Volumes (IRV + VT + ERV + RV)

What does a vital capacity contain?

Sum of IRV + VT + ERV

What is the inspiratory capacity made up of?

Sum of IRV + Vt

Volume of Air Inhaled or Exhaled with Each Breath

Tidal Volume (VT or TV)

Volume of Air Present in Lungs Following a Maximal Inspiratory Effort

Total Lung Capacity (TLC)

What percentage of TLC can the FRC be?

Up to 50%

Volume of Air Exhaled During a Maximal Forced Expiration

Vital Capacity

Why are the changes related to the effects of gravity on the diaphragm as opposed to the lungs?

a) Abdominal Contents Pulled Downward by Gravity and Diaphragm Returns to Anatomical Position; (Sitting); Intercostal Muscles and Diaphragm Exert Greater Recoil on Chest Wall (Sitting) b) Chest Wall Curve Shifts to Right (Sitting to Supine)

What are the static compliance (parameters)

a) Outward Recoil of Chest Wall b) Inward Recoil of Lungs c) Measure Alveolar, Intrapleural Pressures and Lung Volumes In Different Body Positions - Creates "Relaxation Pressures" at Different Lung Volumes d) Plot Lung Volumes (Absolute) or Lung Volumes as a Percentage of the Vital Capacity vs Relaxation Pressure

Inhalation can occur before relaxation volume is reached due to what?

a) Rapid Shallow Breathing b) Emphysema: Structural Changes in Airways c) Partial Obstruction of Airway (Asthma)

What is the normal vital capacity?

4.5L

What is the average tidal volume at rest?

500 mL

What is the normal value for minimal air?

500 mL

What is the normal total lung capacity?

6L

Maximum Volume of Air that can be Exhaled During a Forcible Exhalation (Starts at the End of a Normal Passive Exhalation)

Expiratory Reserve Volume (ERV)

What is the normal functional residual capacity?

3L

What is the normal inspiratory capacity?

3L

What does the functional residual capacity consist of?

ERV + RV

Emphysema a. Reduction of Elastic Fibers in _____ b. Reduction of _____ Supporting Tissue c. Destruction of Alveoli and Alveolar _____ d. Destruction of _____ _____ (Occurs with Destruction of Alveolar Septa) e. Increase in _____ Cells and Decrease of _____ Cells

-Alveoli -Bronchiolar -Septa -Capillary Beds -Goblet; Ciliated

What are examples of obstructive disorders?

-Asthma -Emphysema

FRC can be Lesser than Relaxation Volume (at Rest) if the _____ _____ Changes; Standing to Supine Abdominal Contents Abut Against Inferior Surface of Diaphragm Due to Change in Force Vector of Gravity; This Causes a Reduction in the Expression of the _____ _____ _____ of the Thorax (Lev p. 32, 34 and 60) thus Reducing FRC to Approximately _____ L

-Body Position -Outward Elastic Forces -2L

Changes in body position from sitting to standing are Related to Effects of Gravity on Mechanics of the Chest Wall - Greatest Effect on Chest Wall and Mostly on the _____ Rather than on _____

-Diaphragm -Lungs

Functional Residual Capacity At End _____ Respiratory Muscles are in Their Resting Position Muscles themselves Exert an Outwardly-Directed Muscular Elastic Force on the Thorax; This is a Force Attempting to Keep Alveoli Open thus Opposing the _____ _____ of the Lungs and Surface Tension Forces in Alveoli that are Attempting to Collapse Alveoli

-Expiration -Elastic Forces

Functional Residual Capacity During _____, Stretched Lung Elastic Tissues Recoil to Resting Length; This Recoil Passively Pulls Alveolar Walls to their _____ Position; Surface Tension at Inner Lining of Alveolar Epithelium Assists in the Return of Alveoli to their Resting Position by Compression Combined Forces are Inwardly Directed

-Expiration -Resting

Functional Residual Capacity At End _____ Contraction of Inspiratory Muscles Have Compressed Musculature of Thorax (Muscle Length Shortens) This Causes Stretch on the Elastic Elements of the chest wall musculature (within _____ Muscles)

-Inspiration -Inspiratory

Functional Residual Capacity At End _____, Contraction of _____ Muscles Have Expanded the Lungs and Stretched Elastic Components of Lung Tissues

-Inspiration -Inspiratory

FRC is considered to be a balance point between which two opposing forces?

-Inward force and outward force

Amount of Gas Remaining in Lungs Following a Complete Collapse of Lungs -Is this a functional volume?

-Minimal Air -No

What are restrictive disorders related to?

-Movement of lungs or thorax

What are examples of restrictive diseases?

-Pulmonary fibrosis -Reduction in surfactant -Kyphoscoliosis -Obesity -Neuromuscular diseases (myasthenia gravis, ALS)

Functional Residual Capacity During Passive _____ of Respiratory Muscles; Stretched Muscular Elastic Elements are Rebounding and Returning Muscles to Their Resting Position by _____

-Relaxation -Recoil

How do you indirectly measure tidal volume?

1) VT = 3.24x Body Weight in Pounds (3.24ml/lb) or 2) VT = 7-8x Body weight in Kilograms (7-8ml/Kg)

What is the normal expiratory reserve volume?

1.5L

What is the normal residual volume?

1.5L

What is the normal inspiratory reserve volume?

2.5L

When does vital capacity start?

After a forced maximal inspiration

When does the inspiratory capacity begin?

At the end of a tidal expiration