Part 1 Structure and Function of the Respiratory System - PowerPoint PPT Presentation

View by Category
About This Presentation
Title:

Part 1 Structure and Function of the Respiratory System

Description:

Part 1 Structure and Function of the Respiratory System When you can not breath, nothing else matters Slogan of the American Lung Association Respiratory System ... – PowerPoint PPT presentation

Number of Views:314
Avg rating:3.0/5.0
Slides: 42
Provided by: liucy
Learn more at: http://course.sdu.edu.cn
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Part 1 Structure and Function of the Respiratory System


1
(No Transcript)
2
Part 1 Structure and Function of the Respiratory
System
  • When you can not breath, nothing else matters
  • Slogan of the American Lung Association

3
Respiration is the process by which the body
takes in and utilizes oxygen (O2) and gets rid of
carbon dioxide (CO2).
4
An Overview of Key Steps in Respiration
5
Respiration can be divided into four major
functional events
  • Ventilation Movement of air into and out of
    lungs
  • Gas exchange between air in lungs and blood
  • Transport of oxygen and carbon dioxide in the
    blood
  • Internal respiration Gas exchange between the
    blood and tissues

6
Respiratory System Functions
  • Gas exchange Oxygen enters blood and carbon
    dioxide leaves
  • Regulation of blood pH Altered by changing blood
    carbon dioxide levels
  • Voice production Movement of air past vocal
    folds makes sound and speech
  • Olfaction Smell occurs when airborne molecules
    drawn into nasal cavity
  • Protection Against microorganisms by preventing
    entry and removing them
  • Metabolism Synthesize and metabolize different
    compounds (Nonrespiratory Function of the Lung)

7
Section I ANATOMY OF THE RESPIRATORY TRACT
8
Respiratory System Divisions
  • Upper Airway
  • Nose, pharynx, larynx and associated structures
  • Lower Airway
  • trachea, bronchi, lungs

9
Conducting Zone
  • All the structures air passes through before
    reaching the respiratory zone.
  • Cartilage holds tube system open and smooth
    muscle controls tube diameter
  • Warms and humidifies inspired air.
  • Filters and cleans

Insert fig. 16.5
10
Respiratory Zone
  • Region of gas exchange between air and blood.
  • Includes respiratory bronchioles and alveolar
    sacs.

11
Airway branching
12
Section II BLOOD SUPPLY TO THE LUNG
  • Two separate blood supplies pulmonary
    circulation and bronchial circulation
  • Pulmonary circulation
  • Bronchial circulation

13
Pulmonary circulation
  • Brings deoxygenated blood from the right
    ventricle to the gas-exchange units
  • At the gas-exchanging units, oxygen is picked up
    and carbon dioxide is removed from the blood
  • The oxygenated blood returned to the left atrium
    for distribution to the rest of the body

14
Bronchial circulation
  • Arise from the aorta
  • Provides nourishments to the lung parenchyma(???)

15
Section III MUSCLES OF RESPIRATION
  • Inspiratory muscle
  • Diaphragm and Abdominal breathing (????)
  • external intercostal muscle and thoracic
    breathing (????)
  • accessory muscle of inspiration
  • Expiratory muscle
  • relax during normal breathing
  • Internal intercostal muscle
  • Muscles of the abdominal wall

16
Thoracic Walls and Muscles of Respiration
17
Breathing Rate
  • At rest 10-20 breaths / minute
  • During exercise 40 - 45 at maximum exercise in
    adults

18
Thoracic Volume
19
Mechanisms of Breathing How do we change the
volume of the rib cage ?
  • To Inhale is an ACTIVE process
  • Diaphragm
  • External Intercostal Muscles

Both actions occur simultaneously otherwise not
effective
20
Pleura
21
  • Pleural fluid produced by pleural membranes
  • Acts as lubricant
  • Helps hold parietal and visceral pleural
    membranes together

22
Ventilation
  • Movement of air into and out of lungs
  • Air moves from area of higher pressure to area of
    lower pressure
  • Pressure is inversely related to volume

23
Alveolar Pressure Changes During Respiration
24
Principles of Breathing
Functional Unit Chest Wall and Lung
Follows Boyles LawPressure (P) x Volume (V)
Constant
25
Principle of Breathing
Follows Boyles Law PV C
At Rest with mouth open Pb Pi 0
Pb
Airway Open
A
Pi
PS
D
1
26
Principle of Breathing
Follows Boyles Law PV C
  • At Rest with mouth open Pb Pi 0
  • Inhalation
  • Increase Volume of Rib cage
  • Decrease the pleural cavity pressure- Decrease
    in Pressure inside (Pi) lungs

Pb
Airway Open
A
Pi
PS
CW
D
2
27
Principle of Breathing
Follows Boyles Law PV C
  • At Rest with mouth open Pb Pi 0
  • Inhalation
  • Pb outside is now greater than Pi- Air flows
    down pressure gradient
  • Until Pi Pb

Pb
Airway Open
A
Pi
CW
PS
D
3
28
Principle of Breathing
Follows Boyles Law PV C
  • At Rest with mouth open Pb Pi 0
  • Exhalation Opposite Process
  • Decrease Rib Cage Volume

Pb
Airway Open
A
Pi
CW
PS
D
4
29
Principle of Breathing
Follows Boyles Law PV C
  • At Rest with mouth open Pb Pi 0
  • Exhalation Opposite Process
  • Decrease Rib Cage Volume
  • Increase in pleural cavity pressure -
    Increase Pi

Pb
Airway Open
A
Pi
CW
PS
D
5
30
Principle of Breathing
Follows Boyles Law PV C
  • At Rest with mouth open Pb Pi 0
  • Exhalation Opposite Process
  • Decrease Rib Cage Volume
  • Increase Pi
  • Pi is greater than Pb
  • Air flows down pressure gradient
  • Until Pi Pb again

Pb
Airway Open
A
Pi
CW
PS
D
6
31
(No Transcript)
32
Section IV SURFACTANT AND SURFACE TENSION
  • Surface tension (????) a measure of the
    attraction force of the surface molecules per
    unit length of the material to which they are
    attached

33
Surface Tension
  • Force exerted by fluid in alveoli to resist
    distension
  • Lungs secrete and absorb fluid, leaving a very
    thin film of fluid.
  • H20 molecules at the surface are attracted to
    other H20 molecules by attractive forces.
  • Force is directed inward, raising pressure in
    alveoli.

34
What is Surface Tension ?
35
Surface Tension
  • Law of Laplace
  • Pressure in alveoli
  • directly proportional to surface tension
  • inversely proportional to radius of alveoli
  • if surface tension were the same in all
    alveolus....

Insert fig. 16.11
36
Effect of Surface Tension on Alveoli size
37
Surfactant (??????)
  • Phospholipid produced by alveolar type II cells.
  • Lowers surface tension.
  • Reduces attractive forces of hydrogen bonding
  • by becoming interspersed between H20 molecules.
  • Surface tension in alveoli is reduced.

38
Area dependence of Surfactant action
39
Surfactant prevents alveolar collapse
40
Volume L
6
3
Without surfactant
RV
Pleural Pressure
0
0
- 30 cm H2O
- 15
Volume-pressure curves of lungs filled with
saline and with air (with or without surfactant)
41
Physiology Importance of Surfactant
  • Reduce the work of breathing
  • Stabilize alveoli
  • Prevent collapse and sticking of alveoli
  • Maintain the dryness of the alveoli
  • Prevent the edema of the alveoli
About PowerShow.com