Transcript The Respiratory System ch14

The Respiratory System ch14
• The primary function of the respiratory system is to allow
oxygen from the air to enter the blood and carbon dioxide
from the blood to exit into the air.
• Inspiration –inhalation (breathing in)
• Expiration- exhalation ( breathing out)
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The Nose
Functions
•Provides an airway for respiration
•Moistens and warms entering air
•Filters and cleans inspired air
•Resonating chamber for speech
•Detects odors in the airstream
•Respiratory mucosa-contains goblet cells that
secrete mucus
Mucus
oStickiness traps inhaled particles
oLysozyme kills bacteria
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Nasal cavity
•Vibrissae (guard hairs) – stiff hairs that
filter large particles from the air
•Nasal cilia – hair-like projections that
propel trapped particles towards the throat
for digestion by digestive enzymes
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•Rich supply of capillaries warm the
inspired air
•Nasal conchae – folds in the mucous
membrane that increase air turbulence
and ensures that most air contacts the
mucous membranes
•Olfactory mucosa – mucous
membranes that contain smell
receptors
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The Nose, Nasal Cavity, and Pharynx
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Figure 23.3c
The Pharynx (throat)
Funnel shaped passageway that connects the
nasal and oral cavities to the larynx
Three regions of the pharynx
•Nasopharynx – air passage
•Oropharynx – passageway for air, food,
and drink
•Laryngopharynx – passageway for air,
food, and drink
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The Larynx (voice box)
Functions :
•Keeps food and drink out of the airway
•Sound production
Anatomical Features:
•Nine c-rings of hyaline cartilage form the framework
of the larynx (the apex of this triangular box is called
the Adam’ss apple
•Muscular walls aid in voice production and the
swallowing reflex
•Glottis – the superior opening of the larynx
•Epiglottis – prevents food and drink from entering
airway when swallowing
•False vocal cords – aid in closing the glottis when
swallowing
•True vocal cords – produce sound when air passes
between them
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The Anatomy of the Larynx
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Figure 23.4
The Glottis
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Figure 23.5a, b
The Trachea (windpipe)
Functions :
•Air passageway
•Cleans, warms, and moistens incoming air
Anatomical features :
•Rings of hyaline cartilage – reinforce the trachea
and keep it from collapsing when you inhale
•Traps inhaled debris and propels mucus up to the
pharynx where it is swallowed
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The Anatomy of the Trachea
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Figure 23.6a, b
Bronchi
Function :
•Solely an air passageway
Anatomical features :
•Left and right primary bronchi branch off from
trachea
•Once the left and right primary bronchi enter the
lungs they are subdivided into smaller tubes:
Secondary bronchi (one for each lobe) → tertiary
bronchi → bronchioles → terminal bronchioles →
respiratory bronchioles → alveolar ducts → alveolar
sacs
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The Bronchi and Lobules of the Lung
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Figure 23.10a
The Lungs
•Left
Divided into 2 lobes
Smaller than the right lung
Cardiac notch accommodates the heart
•Right
Divided into 3 lobes
•Each lobe is separated by connective tissue and has it
own arteries and veins.
•Serous membranes-cover the entire surface of the lungs and
produce pleural fluid -enables the lungs to expand and
contract with minimal friction
•Visceral –adheres to the surface of the lung
•Parietal- lines the thoracic cavity
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The Gross Anatomy of the Lungs
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Figure 23.7
The Bronchi and Lobules of the Lung
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Figure 23.10b
The Alveoli
•Alveolar sacs-clusters of alveoli
•Alveoli- the site of gas exchange which
occurs between the air in the alveoli and
capillaries
•Alveolar cells – allow for diffusion of gases
& secrete surfactant- reduces the surface
tension of fluid in the lungs and helps make
(alveoli) more stable. This keeps them from
collapsing when an individual exhales
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Alveolar Organization
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Figure 23.12a-c