Respiratory System Anatomy & Physiology for Nurses

1. HUMAN RESPIRATORY SYSTEM
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2. Lecture Outline
At the end of this unit learners will be able
to:
1.Define respiratory system.
2.Define respiration.
3.Describe the structure and function of
upper respiratory and lower respiratory
tract.
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3. Lecture Outline
• 4. Discuss the physiology of respiration by
explaining the mechanism of:
• 􀂉 Pulmonary Ventilation
• 􀂉 External Respiration
• 􀂉 Internal Respiration
• 5. Discuss nervous control of respiration.
• 6. Briefly discuss the lung volumes &
capacities.
• 7. References 3

4. * It is the system, consisting of tubes and is
responsible for the exchange of gases in
Humans by filtering incoming air
and transporting it into the microscopic
alveoli where gases are exchanged
* Your respiratory system provides the energy
needed by cells of the body to funtion
accroding to their designated tasks.
THE HUMAN RESPIRATORY SYSTEM
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5. THE HUMAN RESPIRATORY SYSTEM
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6. The organs of the
“Respiratory Tract”
can be divided into two groups
“STRUCTURALLY”
** The Upper Respiratory Tract ** The Lower Respiratory Tract
* Nose
* Nasal cavity
* Sinuses
* Pharynx
* Larynx
* Trachea
* Bronchial Tree
* Lungs
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7. THE HUMAN RESPIRATORY SYSTEM
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8. The organs of the
“Respiratory Tract”
can be divided into two groups
“FUNCTIONALLY”
** The Conducting Portion
- system of interconnecting
cavities and tubes that
conduct air into the lungs
** The Respiratory Portion
- system where the exchange of
respiratory gases occurs
* Nose
* Pharynx
* Larynx
* Trachea
* Bronchi
* Respiratory
bronchioles
* Alveolar Ducts
* Alveoli
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9. The Respiratory Epithelium
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10. THE HUMAN RESPIRATORY SYSTEM
I. N O S E
A. N a s a l C a v i t y
B. P a r a n a s a l S i n u s e s
II. P H A R Y N X
III. L A R Y N X
A. E p I g i o t t i s
B. V o c a l C o r d s
IV. T R A C H E A
v. B R O N C H I
A. B r o n c h i a l T r e e
VI. L U N G S
A. L o b e s o f t h e L u n g s
B. P l e u r a l C a v i t i e s
C. A l v e o l i 10

11. THE NOSE
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12. * It provides an entrance for air in which air is
filtered by coarse hairs inside the nostrils.
* It has 2 portions : the external and internal
* The external portion is supported by a framework
of bone and cartilage covered with skin and
lined with mucous membrane.
* The internal portion is a large cavity in the skull,
merging with the extrenal nose anteriorly and
communicating with the throat posteriorly.
THE NOSE
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13. The Nasal Cavity
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14. * Interior area of the nose; lined with a sticky mucous
membrane and contains tiny, surface hairs,
cilia. divided medially by the nasal septum.
* Nasal conchae divide the cavity into passageways
that are lined with mucous membrane,
and help increase the surface area available
to warm and filter incoming air.
•Particles trapped in the mucus are carried to the
pharynx by ciliary action, swallowed,
and carried to the stomach where gastric juice
destroys any microorganisms in the mucus.
The Nasal Cavity
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15. Paranasal Sinuses
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16. * Sinuses are air-filled spaces
within the maxillary, frontal, ethmoid,
and sphenoid bones of the skull.
* These spaces open to the nasal cavity
and are lined with mucus membrane
that is continuous with that lining the nasal cavity.
* The sinuses reduce the weight of the skull
and serve as a resonant chamber to affect
the quality of the voice.
Paranasal Sinuses
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17. THE PHARYNX
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18. * The “throat” is a funnel shaped tube that lies posterior
to the nasal cavity, oral cavity and larynx;
and anteriorly to the cervical vertebra.
* It is composed of:
Nasopharynx – uppermost portion
Oropharynx – middle portion
Laryngopharynx – lowermost portion
* It is a common passageway for air and food and it
provides a resonating chamber for speech sounds
THE PHARYNX
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19. THE LARYNX
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20. * It is an enlargement in the airway
superior to the trachea and inferior to the pharynx.
* It helps keep particles from entering the trachea
and also houses the vocal cords.
* It is composed of a framework of muscles
and cartilage bound by elastic tissue
THE LARYNX
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21. The
Epiglottis
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22. * It is a large leaf-shaped piece of cartilage.
* A flap of cartilage that prevents food from
entering the trachea (or windpipe).
* During swallowing, there is elevation of the larynx
The Epiglottis
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23. The Vocal Cords
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24. * Inside the larynx, 2 pairs of folds of muscle and
connective tissues covered with mucous
membrane make up the vocal cords.
a. The upper pair is the false vocal cords.
b. The lower pair is the true vocal cords.
c. Changing tension on the vocal cords controls pitch,
while increasing the loudness depends upon
increasing the force of air vibrating the vocal cords.
The Vocal Cords
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25. * During normal breathing,
the vocal cords are relaxed and the
glottis is a triangular opning.
* During swallowing,
the false vocal cords and epiglottis
close off the glottis.
The Vocal Cords
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26. THE TRACHEA
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27. * It is a tubular passageway for air, located anterior
to the esophagus
* It extends from the larynx to the 5th thoracic vertebra
where it divides into the right and left bronchi.
THE TRACHEA
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28. THE TRACHEA
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29. * The inner wall of the trachea is lined with
ciliated mucous membrane with many
goblet cells that serve to trap incoming particles.
* The tracheal wall is supported by
20 incomplete cartilaginous rings.
THE TRACHEA
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30. BRONCHI
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31. * The Bronchi are the two main air passages
into the lungs.
* They are composed of the:
** “Right Primary Bronchus”
- leading to the right lung.
** “Left Primary Bronchus”
- leading to the left lung.
BRONCHI
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32. The Bronchial Tree
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33. * The bronchial tree consists of branched tubes
leading from the trachea to the alveoli.
* The bronchial tree begins with the two
primary bronchi, each leading to a lung.
* The branches of the bronchial tree from the trachea
are right and left primary bronchi;
these further subdivide until bronchioles
give rise to alveolar ducts which terminate in alveoli.
* It is through the thin epithelial cells of the alveoli
that gas exchange between the blood and air occurs.
The Bronchial Tree
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34. THE LUNGS
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35. •The paired soft, spongy, cone-shaped lungs,
separated medially by the mediastinum and are
enclosed by the diaphragm and thoracic cage.
•2 layers of serous membrane, collectively known as
pleural membrane, enclose and protect each lung.
** Parietal Pleura
- outer layer attached to the thoracic cavity
** Visceral Pleura
- inner layer covering the lung itself
THE LUNGS
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36. Right-3 lobes Left-2 lobes
THE LUNGS
trachea
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37. * The two organs that extract oxygen from
inhaled air and expel carbon dioxide
in exhaled air.
* This is the main and primary organ of the
Respiratory System.
* The bronchus and large blood vessels enter each lung.
THE LUNGS
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38. Lobes of the Lungs
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39. * The right lung has three lobes.
* The left lung has two lobes.
* Each lobe is composed of lobules
that contain air passages, alveoli, nerves,
blood vessels, lymphatic vessels,
and connective tissues.
Lobes of the Lungs
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40. The Pleural Cavities
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41. * A layer of serous membrane, between the
visceral pleura and the parietal pleura.
* It contains a lubricating fluid secreted by the
membranes that prevents friction between the
membranes and allows their easy movement
on one another during breathing.
The Pleural Cavities
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42. The Alveoli
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43. * They are cup-shaped out pouching lined
by epithelium and supported by a thin elastic
basement membrane.
•With that you can imagine having bunch of grapes
with each grape indicating and alveolus.
* Alveolar sacs are 2 or more alveoli that
share a common opening.
* This is where the primary exchange of gases occur.
The Alveoli
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44. Respiratory Centers of the CNS
• The primary
portions of the
brainstem that
control
ventilation are
the medulla
oblongata and
the pons.
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45. 45
Respiratory Centers

46. 46
Two respiratory nuclei in medulla oblongata
Expiratory center (ventral
respiratory group, VRG)
•involved in forced
expiration
Inspiratory center (dorsal respiratory group, DRG)
• more frequently they fire, more deeply you
inhale
• longer duration they fire, breath is prolonged,
slow rate

47. 47
Respiratory Centers in Pons
Apneusticcenter (lower pons)
•Sends continual inhibitory impulses to inspiratory
center of the medulla oblongata,
•As impulse frequency rises, breathe faster and
shallower
•Stimulation causes apneusis
•Integrates inspiratory cutoff
information
Pneumotaxic center (upper pons)

48. Lung Volumes and Capacities
• The tidal volume (TV), about 500 mL, is
the amount of air inspired during normal,
relaxed breathing.
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49. The inspiratory reserve
volume (IRV)
• About 3,100 mL, is the additional air that
can be forcibly inhaled after the inspiration
of a normal tidal volume.
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50. expiratory reserve volume
(ERV)
• about 1,200 mL, is the additional air that
can be forcibly exhaled after the expiration
of a normal tidal volume.
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51. Residual volume (RV)
• about 1,200 mL, is the volume of air still
remaining in the lungs after the expiratory
reserve volume is exhaled.
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52. Total Lung Capacity (TLC),
• about 6,000 mL, is the maximum amount
of air that can fill the lungs (TLC = TV +
IRV + ERV + RV).
• The vital capacity (VC), about 4,800 mL,
is the total amount of air that can be
expired after fully inhaling (VC = TV + IRV
+ ERV = approximately 80 percent TLC).
The value varies according to age and
body size. 52

53. inspiratory capacity (IC)
• The), about 3,600 mL, is the maximum
amount of air that can be inspired (IC = TV
+ IRV).
• The functional residual capacity (FRC),
about 2,400 mL, is the amount of air
remaining in the lungs after a normal
expiration (FRC = RV + ERV).
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54. Dead Space
• Some of the air in the lungs does not
participate in gas exchange. Such air is
located in the anatomical dead space
within bronchi and bronchioles—that is,
outside the alveoli.
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55. STRUCTURE FUNCTION
nose / nasal cavity warms, moistens, & filters air as it is inhaled
pharynx (throat) passageway for air, leads to trachea
larynx the voice box, where vocal chords are located
trachea (windpipe)
tube from pharynx to bronchi
rings of cartilage provide structure, keeps the
windpipe "open"
trachea is lined with fine hairs called cilia which
filter air before it reaches the lungs
bronchi
two branches at the end of the trachea, each lead
to a lung
bronchioles
a network of smaller branches leading from the
bronchi into the lung tissue & ultimately to air
sacs
alveoli
the functional respiratory units in the lung where
gases (oxygen & carbon dioxide) are exchanged
(enter & exit the blood stream)
Summary
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56. References
• Ross, & Wilson. (2000) Anatomy &
Physiology in Health & Illness.Edinburgh:
Churchill. Eight Edition.
• Tortora, G. J. (2000). Principles of Human
Anatomy and Physiology (3rd ed). New
York: Happer & Row.
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