Transcript The Respiratory System

The Respiratory System
• 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
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Goblet Cells
Respiratory mucosa-contains
goblet cells that secrete mucus
•Mucus
•Stickiness traps inhaled
particles
•Lysozymes 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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Nasal Cavity cont.
•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 Pharynx (throat)
• Funnel shaped
passageway that
connects the nasal and
oral cavities to the
larynx
• Three regions of the
pharynx
• Nasopharynx - air
passage
• Oropharynx &
Laryngopharynxpassageway 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:
• 9 c-rings of hyaline cartilage form the framework of the larynx (the
apex is called the Adam’s 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 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 primary bronchi
enter the lungs they are
subdivided into smaller tubes:
• Secondary bronchi →
tertiary bronchi →
bronchioles → terminal
bronchioles → respiratory
bronchioles → alveolar ducts
→ alveolar sacs
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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 its
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
Alveoli- tiny sacs that are the final
branching of the respiratory tree and
act as the gas exchange units of the
lung.
Alveolar sacs- clusters of alveoli
Alveolar cells – allow for diffusion of
gases & secretion of surfactant -
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Alveoli cont.
• Surfactants are substances that reduce
surface tension of fluid in the lungs and helps
make (alveoli) more stable. keeps them from
collapsing when an individual exhales
• Surface tension-the tendency of molecules
in a fluid to be pulled toward the center of the
fluid
• High surface tension would tend to decrease
the surface area of the lungs, thus making it
harder to absorb air.
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Alveolar Organization
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Figure 23.12a-c