The Respiratory System and Its Functions
Respiratory System
Respiratory System: Overview
Figure 17-2 b: Anatomy Summary
3
Respiration Includes
•
Pulmonary ventilation
–
Air moves in and out of lungs
–
Continuous replacement of gases in alveoli (air sacs)
•
External respiration
–
Gas exchange between blood and air at alveoli
–
O2 (oxygen) in air diffuses into blood
–
CO2 (carbon dioxide) in blood diffuses into air
•
Transport of respiratory gases
–
Between the lungs and the cells of the body
–
Performed by the cardiovascular system
–
Blood is the transporting fluid
•
Internal respiration
–
Gas exchange in capillaries between blood and tissue cells
–
O2 in blood diffuses into tissues
–
CO2 waste in tissues diffuses into blood
Functions of the Respiratory System:
Overview
Figure 17-1: Overview of external and cellular respiration
•
Exchange O
2
–
Air to blood
–
Blood to cells
•
Exchange CO
2
–
Cells to blood
–
Blood to air
•
Filter, warm & moisten air
•
Nose, (mouth), pharynx, larynx, trachea, bronchi &
bronchioles
•
Huge increase in cross sectional area
The Airways:
Conduction of Air from Outside to Alveoli
Figure 17-4: Branching of the airways
6
Nose
•
Provides airway
•
Moistens and warms air
•
Filters air
External nose
7
The Pharynx (throat)
•
Houses tonsils (they respond to inhaled antigens)
•
Uvula closes off nasopharynx during swallowing so food doesn’t
go into nose
•
Epiglottis posterior to the tongue: keeps food out of airway
•
serve as common
passageway for food and air
*
*
8
The Larynx (voicebox)
•
Three functions:
1.
Produces vocalizations (speech)
2.
Provides an open airway (breathing)
3.
Switching mechanism to route air and food into proper
channels
•
Closed during swallowing
•
Open during breathing
9
Trachea (the windpipe)
•
Descends: larynx through neck
•
Divides in thorax into two main (primary) bronchi
•
16-20
C
-shaped rings
of hyaline cartilage
joined by fibroelastic
connective tissue
•
Flexible for bending
but stays open despite
pressure changes
during breathing
trachea
Left
primary
bronchus
Right
Primary
Bronchus
Wider,
shorter, and
more vertical
than the left
Both primary bronchi have the same anatomic structure
as the trachea.
Bronchi
•
The primary bronchi divide to form SECONDARY
BRONCHI
•
There is one secondary bronchus for each lobe of the
lungs.
•
There are 2 lobes on the left lung.
•
There are 3 lobes on the right lung.
•
These also have the same anatomy as the trachea.
Bronchi, continued
•
The secondary bronchi branch to form TERTIARY
BRONCHI.
•
They continue to branch.
•
As they get smaller, they lose their cartilage.
•
When they lose their cartilage, they are called
BRONCHIOLES which are microscopic.
13
Lungs and Pleura
Pleural cavity
– slit-like potential space filled with pleural fluid
•
Lungs can slide but separation from pleura is resisted (like film
between 2 plates of glass)
•
Lungs cling to thoracic wall and are forced to expand and
recoil as volume of thoracic cavity changes during breathing
Around each lung is a flattened sac
of serous membrane called
pleura
Parietal pleura
– outer layer
Visceral pleura
– directly on lung
14
•
Right lung: 3 lobes
–
Upper lobe
–
Middle lobe
–
Lower lobe
•
Left lung: 2 lobes
–
Upper lobe
–
Lower lobe
Oblique fissure
Oblique fissure
Horizontal fissure
Abbreviations in medicine:
e.g.” RLL pneumonia”
Each lobe is served by a
lobar (secondary)
bronchus
The respiratory system is vital for gas exchange in the body, involving processes like pulmonary ventilation, external and internal respiration. It includes organs like the nose, pharynx, larynx, and trachea, which help in conducting air to the alveoli. This system facilitates the exchange of oxygen and carbon dioxide between the blood and cells, supporting cellular respiration. Understanding the anatomy and functions of the respiratory system is crucial for overall health and well-being.
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Presentation Transcript
Respiratory System: Overview Figure 17-2 b: Anatomy Summary
Respiration Includes Pulmonary ventilation Air moves in and out of lungs Continuous replacement of gases in alveoli (air sacs) External respiration Gas exchange between blood and air at alveoli O2 (oxygen) in air diffuses into blood CO2 (carbon dioxide) in blood diffuses into air Transport of respiratory gases Between the lungs and the cells of the body Performed by the cardiovascular system Blood is the transporting fluid Internal respiration Gas exchange in capillaries between blood and tissue cells O2 in blood diffuses into tissues CO2 waste in tissues diffuses into blood 3
Functions of the Respiratory System: Overview Exchange O2 Air to blood Blood to cells Exchange CO2 Cells to blood Blood to air Figure 17-1: Overview of external and cellular respiration
The Airways: Conduction of Air from Outside to Alveoli Filter, warm & moisten air Nose, (mouth), pharynx, larynx, trachea, bronchi & bronchioles Huge increase in cross sectional area Figure 17-4: Branching of the airways
Nose Provides airway Moistens and warms air Filters air External nose 6
The Pharynx (throat) Houses tonsils (they respond to inhaled antigens) Uvula closes off nasopharynx during swallowing so food doesn t go into nose Epiglottis posterior to the tongue: keeps food out of airway serve as common passageway for food and air * * 7
The Larynx (voicebox) Three functions: 1. Produces vocalizations (speech) 2. Provides an open airway (breathing) 3. Switching mechanism to route air and food into proper channels Closed during swallowing Open during breathing 8
Trachea (the windpipe) Descends: larynx through neck Divides in thorax into two main (primary) bronchi 16-20 C-shaped rings of hyaline cartilage joined by fibroelastic connective tissue Flexible for bending but stays open despite pressure changes during breathing 9
Wider, shorter, and more vertical than the left trachea Right Primary Bronchus Left primary bronchus Both primary bronchi have the same anatomic structure as the trachea.
Bronchi The primary bronchi divide to form SECONDARY BRONCHI There is one secondary bronchus for each lobe of the lungs. There are 2 lobes on the left lung. There are 3 lobes on the right lung. These also have the same anatomy as the trachea.
Bronchi, continued The secondary bronchi branch to form TERTIARY BRONCHI. They continue to branch. As they get smaller, they lose their cartilage. When they lose their cartilage, they are called BRONCHIOLES which are microscopic.
Lungs and Pleura Around each lung is a flattened sac of serous membrane called pleura Parietal pleura outer layer Visceral pleura directly on lung Pleural cavity slit-like potential space filled with pleural fluid Lungs can slide but separation from pleura is resisted (like film between 2 plates of glass) Lungs cling to thoracic wall and are forced to expand and recoil as volume of thoracic cavity changes during breathing 13
Right lung: 3 lobes Upper lobe Middle lobe Lower lobe Left lung: 2 lobes Upper lobe Lower lobe Abbreviations in medicine: e.g. RLL pneumonia Horizontal fissure Oblique fissure Oblique fissure Each lobe is served by a lobar (secondary) bronchus 14
