Transcript Lungs - SchoolRack

Opener
• Given what you
know about
bloodflow and
breathing, how are
the circulatory and
respiratory systems
related?
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Objectives
• Understand the location and function of the
main structures of the respiratory system
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Respiration
• Involves both
the respiratory
and the
circulatory
systems
• Supply the body
with O2 and
dispose of CO2
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Respiration involves 4 processes
• Pulmonary ventilation (breathing):
movement of air into and out
of the lungs
• External respiration: O2 and CO2
exchange between the lungs
and the blood
• Transport: O2 and CO2
in the blood
• Internal respiration: O2 and CO2
exchange between systemic blood
vessels and tissues
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Respiratory
system
Circulatory
system
Respiratory System: Functional Anatomy
• Major organs
• Nose, nasal cavity, and
paranasal sinuses
• Pharynx
• Larynx
• Trachea
• Bronchi and their
branches
• Lungs and alveoli
Intro video
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The Nose
• Functions
• Airway
• Moistens and warms
air
• Filters and cleans air
• Resonating chamber
for speech
• Houses olfactory
receptors
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Pharynx
• Passageway
• 3 divisions
• Nasopharynx: just air
• Uvula
• Oropharynx: air and
food
• Laryngopharynx: food
and air
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Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
(b) Regions of the pharynx
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Figure 22.3b
Larynx
• Superior to the trachea, inferior to pharynx
• Functions
1. Provides airway
2. Routes air and food
3. Voice production
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Epiglottis
Thyrohyoid
membrane
Body of hyoid bone
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
Cricothyroid ligament
Cricoid cartilage
Cricotracheal ligament
Tracheal cartilages
(a) Anterior superficial view
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Figure 22.4a
Epiglottis
Body of hyoid bone
Thyrohyoid
membrane
Cuneiform cartilage
Corniculate cartilage
Arytenoid cartilage
Arytenoid muscles
Cricoid cartilage
Thyrohyoid membrane
Fatty pad
Vestibular fold
(false vocal cord)
Thyroid cartilage
Vocal fold
(true vocal cord)
Cricothyroid ligament
Cricotracheal ligament
Tracheal cartilages
(b) Sagittal view; anterior surface to the right
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Figure 22.4b
Larynx
• Contains vocal folds
• Opening between
them is the glottis
• Folds vibrate to
produce sound as
air rushes up from
the lungs
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Base of tongue
Epiglottis
Vestibular fold
(false vocal cord)
Vocal fold
(true vocal cord)
Glottis
Inner lining of trachea
Cuneiform cartilage
Corniculate cartilage
(a) Vocal folds in closed position;
closed glottis
(b) Vocal folds in open position;
open glottis
video
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Figure 22.5
Voice Production
• Speech: air let out as glottis opens
and closes
• Pitch: determined by the length and
tension of the vocal cords
• Loudness: depends upon the force
of air that leaves
• Other structures and muscles adjust
into language
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video
Trachea: windpipe: from the larynx into the
chest
Posterior
Mucosa
Submucosa
Esophagus
Trachealis
muscle
Lumen of
trachea
Seromucous gland
in submucosa
Hyaline cartilage
Adventitia
Anterior
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Figure 22.6a
Conducting Zone Structures
• Trachea  right
and left bronchi
• Each enters one
lung
• Each branches into
smaller and smaller
structures
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Trachea
Middle lobe
of right lung
Superior lobe
of left lung
Left main
(primary)
bronchus
Lobar
(secondary)
bronchus
Segmental
(tertiary)
bronchus
Inferior lobe
of right lung
Inferior lobe
of left lung
Superior lobe
of right lung
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Figure 22.7
OPENER
• What are some
ways your
speech is
controlled by
anatomical
structures?
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Objectives
• Apply gas laws to the process of breathing
• Evaluate lung function using lung volume
readings
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Respiratory Zone
• Respiratory
bronchioles, alveolar
ducts, alveolar sacs
(clusters of alveoli)
• ~300 million alveoli
account for most of
the lungs’ volume
and are the main site
for gas exchange
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Alveoli
Alveolar duct
Respiratory
bronchioles
Terminal
bronchiole
Alveolar duct
Alveolar
sac
(a)
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Figure 22.8a
Respiratory
bronchiole
Alveolar
duct
Alveolar
pores
Alveoli
(b)
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Alveolar
sac
Figure 22.8b
Respiratory Membrane
• ~0.5-m-thick air-blood barrier
• Alveolar and capillary walls
• Alveolar walls
• Single layer of squamous epithelium
• Other cells secrete mucous
video
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Terminal bronchiole
Respiratory bronchiole
Smooth
muscle
Elastic
fibers
Alveolus
Capillaries
(a) Diagrammatic view of capillary-alveoli relationships
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Figure 22.9a
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Figure 22.9b
Red blood
cell
Nucleus of type I
(squamous
epithelial) cell
Alveolar pores
Capillary
O2
Capillary
CO2
Alveolus
Alveolus
Type I cell
of alveolar wall
Macrophage
Endothelial cell nucleus
Alveolar
epithelium
Fused basement
membranes of the
Respiratory alveolar epithelium
membrane and the capillary
Red blood cell
endothelium
Alveoli (gas-filled in capillary
Type II (surfactantCapillary
air spaces)
secreting) cell
endothelium
(c) Detailed anatomy of the respiratory membrane
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Figure 22.9c
Lungs
• Occupy all of the thoracic cavity except the
mediastinum
• Apex: superior tip
• Base: inferior surface that rests on the
diaphragm
• Hilum: point at center where everything goes
in
• Cardiac notch of left lung: dent for heart to sit
in
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Trachea
Thymus
Lung
Intercostal
muscle
Rib
Parietal pleura
Pleural cavity
Visceral pleura
Apex of lung
Right superior lobe
Horizontal fissure
Heart
(in mediastinum)
Right middle lobe
Oblique fissure
Right inferior lobe
Diaphragm
Base of lung
Left
superior lobe
Oblique
fissure
Left inferior
lobe
Cardiac notch
(a) Anterior view. The lungs flank mediastinal structures laterally.
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Figure 22.10a
Lungs
• Left lung is
smaller,
separated into
two lobes
• Right lung has
three lobes
• Protected by
pleurae
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Breathing
• Inspire/expire
• Largely regulated by
pressure
• Intrapulmonary: P
inside lungs
• Atmospheric: P
outside
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Breathing
video
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Sequence of events
Changes in anteriorposterior and superiorinferior dimensions
Changes in lateral
dimensions
(superior view)
1 Inspiratory muscles
contract (diaphragm
descends; rib cage rises).
2 Thoracic cavity volume
increases.
Ribs are elevated
and sternum flares
as external
intercostals
contract.
3 Lungs are stretched;
External
intercostals
contract.
intrapulmonary volume
increases.
4 Intrapulmonary pressure
drops (to –1 mm Hg).
5 Air (gases) flows into
lungs down its pressure
gradient until intrapulmonary
pressure is 0 (equal to
atmospheric pressure).
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Diaphragm
moves inferiorly
during contraction.
Figure 22.13 (1 of 2)
Sequence
of events
Changes in anteriorposterior and superiorinferior dimensions
Changes in
lateral dimensions
(superior view)
1 Inspiratory muscles
relax (diaphragm rises; rib
cage descends due to
recoil of costal cartilages).
2 Thoracic cavity volume
Ribs and sternum
are depressed
as external
intercostals
relax.
decreases.
3 Elastic lungs recoil
External
intercostals
relax.
passively; intrapulmonary
volume decreases.
4 Intrapulmonary pres-
sure rises (to +1 mm Hg).
5 Air (gases) flows out of
lungs down its pressure
gradient until intrapulmonary pressure is 0.
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Diaphragm
moves
superiorly
as it relaxes.
Figure 22.13 (2 of 2)
Intrapulmonary
pressure. Pressure
inside lung decreases as
lung volume increases
during inspiration;
pressure increases
during expiration.
Intrapleural pressure.
Pleural cavity pressure
becomes more negative
as chest wall expands
during inspiration.
Returns to initial value
as chest wall recoils.
Volume of breath.
During each breath, the
pressure gradients move
0.5 liter of air into and out
of the lungs.
Inspiration Expiration
Intrapulmonary
pressure
Transpulmonary
pressure
Intrapleural
pressure
Volume of breath
Fire breath
Deep breath
5 seconds elapsed
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Figure 22.14
Respiratory Volume
Spirometer
• Tidal volume: normal breathing
• ~0.5 L
• Inspiratory reserve: extra you can bring in
• ~3 L
• Expiratory reserve
• ~1 L
• Residual volume
• ~1.5 L
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Respiratory Capacity
• Inspiratory capacity: amount you can bring in
• Inspiratory reserve + tidal
• Functional residual capacity: amount typically in
• Expiratory reserve + residual volume
• Vital capacity: amount you can move
• Ir + tidal + er
• Total lung capacity: all volumes
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