THE RESPIRATORY SYSTEM

1
THE RESPIRATORY SYSTEM

• Functions of the respiratory system
• 2. What is respiration?
• 3. Respiratory organs
• 4. Nose anatomy
• 5. Nose physiology
• 6. Pharynx
• 7. Larynx
• Trachea
• Bronchial tree
• Anatomical changes in bronchial tree
• Lungs 1
• Lungs 2
• Alveolar-capillary membrane
• Blood supply of the lungs
• Physiology of respiration
• Inspiration
• Expiration
• Compliance
• Pulmonary volumes, capacities, and rates

• 19. Diffusion of oxygen and carbon dioxide
• Daltons Law
• Partial pressures of oxygen
• Partial pressures of carbon dioxide
• External (pulmonary) respiration
• Internal (tissue) respiration
• Oxygen transport 1
• Oxygen transport 2
• Carbon dioxide transport
• Carbon dioxide in the tissues
• Carbon dioxide in the lungs
• Control of respiration 1
• Control of respiration 2
• Hyperventilation and hypoventilation
• Negative feedback control
• Hypoxia and positive feedback

2
FUNCTIONS OF THE RESPIRATORY SYSTEM
1 -- Gas exchange Receptors for smell Filter,
warm, and moisten incoming air Produce sounds
(phonation) Eliminate some wastes other than CO2
3
RESPIRATORY ORGANS
Upper vs lower tract Conducting vs. respiratory
upper respiratory tract
larynx
trachea
primary bronchi
4
NOSE ANATOMY
5
NOSE PHYSIOLOGY
Filter, warm, moisten air Olfaction Resonating
chamber
6
PHARYNX
Muscular tube Location Constrictor
muscles Divisions
nasal cavity
internal naris
nasopharynx
nasopharynx oropharynx laryngopharynx
oral cavity
oropharynx
laryngopharynx
epiglottis
esophagus
trachea
7
LARYNX
Nine cartilages Thyroid cartilage Epiglottis Crico
id cartilage Laryngospasm Mucosa Vestibular
folds Vocal folds Glottis Voice production
epiglottis
glottis
thyroid cartilage
cricoid cartilage
trachea
ANTERIOR
POSTERIOR
glottis
epiglottis
vocal folds
cartilages
hyoid
thyroid cartilage
cricoid cartilage
vestibular folds
epiglottis
ANTERIOR
tracheal cartilages
8
TRACHEA
Location Mucosa Submucosa Cartilage Trachealis
Adventitia
larynx
trachea
primary bronchi
ciliated pseudostratified columnar epithelium
with goblet cells
transverse section
esophagus
lumen of trachea
mucosa
C-shaped cartilage
ANTERIOR
9
BRONCHIAL TREE
Primary bronchi
trachea
right and left
primary bronchus
Secondary (lobar) bronchi
secondary bronchus
tertiary bronchus
right (3) left (2)
Tertiary (segmental) bronchi
alveolar sac
right (10) left (8)
Bronchioles Terminal bronchioles Respiratory
bronchioles Alveolar ducts and sacs Alveoli
10
ANATOMICAL CHANGES IN BRONCHIAL TREE
Cartilage
Trachea C-shaped cartilage Bronchi irregular
plates of cartilage Bronchioles cartilage gone
11
LUNGS 1
Location Pleurae
RIGHT
LEFT
apex
superior lobe
superior lobe
middle lobe
parietal layer pleural cavity with pleural
fluid visceral layer
inferior lobe
inferior lobe
Apex vs. base Hilus Right lung
diaphragm
base
horizontal fissure
lateral view
3 lobes and 2 fissures
oblique fissure
oblique fissure
Left lung
2 lobes and 1 fissures
hilus
medial view
12
LUNGS 2
Bronchopulmonary segments Lobules Alveolar wall
cell types
respiratory bronchiole
terminal bronchiole
pulmonary artery branch
alveolar sac
13
ALVEOLAR-CAPILLARY MEMBRANE
AKA respiratory membrane Components
Type I septal cell
interstitial space
alveolus
surfactant
surfactant Type I alveolar epithelial cell fused
basement membrane capillary endothelial cell
erythrocyte
O2
CO2
capillary
fused basement membrane
Total surface area 70 m2
endothelial cell
about 25 ft x 30 ft 750 ft2 with 100 ml blood
14
PHYSIOLOGY OF RESPIRATION
What is the purpose of respiration?
What three processes are necessary to accomplish
this task?
pulmonary ventilation external respiration Interna
l respiration
Concepts related to pulmonary ventilation
(breathing)
inspiration (inhalation) vs. expiration
(exhalation) atmospheric pressure intrapulmonic
pressure pressure gradient
15
INSPIRATION
Active process Boyles Law
decrease volume ? increase pressure
air molecule
Phrenic nerves (C3-5) Thoracic nerves (T1 T11)
increase volume ? decrease pressure
16
EXPIRATION
Passive process at rest
elastic recoil surface tension
internal intercostals (11 pairs)
external abdominal oblique
internal abdominal oblique
transversus abdominis
rectus abdominis
760 mmHg
762 mmHg
17
COMPLIANCE
Compliance is the ease with which the lungs and
thoracic wall can be expanded during
inspiration.
Related to two factors
elasticity surface tension
Compliance is decreased with any condition that
destroys lung tissue (emphysema) fills lungs with
fluid (pneumonia) produces surfactant deficiency
(premature birth, near-drowning) interferes with
lung expansion (pneumothorax)
18
PULMONARY VOLUMES, CAPACITIES, AND RATES
maximum inspiration
6000 ml
5000 ml
IRV
VC
TLC
4000 ml
3000 ml
TV
2000 ml
ERV
1000 ml
RV
maximum expiration
SPIROGRAM
19
DIFFUSION OF OXYGEN AND CARBON DIOXIDE
20
PARTIAL PRESSURES OF OXYGEN
alveolar air 104 mmHg
EXTERNAL RESPIRATION
deoxygenated (pulmonary arterial)
blood 40 mmHg
oxygenated (systemic arterial)
blood 104 mmHg
interstitial fluid 40 mmHg
INTERNAL RESPIRATION
cytoplasm lt40 mmHg
21
PARTIAL PRESSURES OF CARBON DIOXIDE
alveolar air 40 mmHg
EXTERNAL RESPIRATION
deoxygenated (pulmonary arterial)
blood 46 mmHg
oxygenated (systemic arterial)
blood 40 mmHg
interstitial fluid 46 mmHg
INTERNAL RESPIRATION
cytoplasm gt46 mmHg
22
EXTERNAL (PULMONARY) RESPIRATION
Alveoli pulmonary blood
INSPIRED AIR PO2 159 PCO2 0.3
EXPIRED AIR PO2 116 PCO2 32
blood gains O2 (oxygenated) blood loses CO2
ALVEOLAR AIR PO2 104 PCO2 40
O2
Diffusion 100 of the time Diffusion rate
dependent on
CO2
DEOXYGENATED BLOOD PO2 40 PCO2 46
OXYGENATED BLOOD PO2 95 PCO2 40
PO2 and PCO2 differences (Henrys Law) total
surface area (Ficks Law) diffusion distance
(Ficks Law) breathing rate and depth
pulmonary artery
pulmonary vein
venous return
aorta
23
INTERNAL (TISSUE) RESPIRATION
Blood tissue cells
pulmonary artery
pulmonary vein
blood loses O2 (deoxygenated) 25 given up
at rest blood gains CO2
aorta
Diffusion 100 of the time
venous return
DEOXYGENATED BLOOD PO2 40 PCO2 46
OXYGENATED BLOOD PO2 95 PCO2 40
O2
TISSUE FLUID PO2 lt40 PCO2 46
CO2
24
OXYGEN TRANSPORT 1
98.5 as oxyhemoglobin Fully saturated vs.
partially saturated saturation of
hemoglobin Oxyhemoglobin-dissociation curve PO2
most important factor
100
80
60
oxygen saturation
40
20
20
100
60
PO2 (mmHg)
23
98
75
LUNGS
TISSUES
25
OXYGEN TRANSPORT 2
Other factors related to hemoglobin saturation
pH (Bohr effect) PCO2 temperature
related
26
CARBON DIOXIDE TRANSPORT
5 dissolved in plasma 5 as carbamino-hemoglobin
90 as bicarbonate ion (HCO3-)
What is the relationship between CO2 and H?
What is the relationship between and H and pH?
So what is the relationship between and CO2 and
pH?
27
CARBON DIOXIDE IN THE TISSUES
PLASMA
5 dissolves into plasma
HCO3-
5 binds to protein portion of Hb
Cl-
diffusion
chloride shift
carbonic anhydrase
CO2
CO2 H20 ? H2CO3 ? H HCO3-
90
CO2
Bohr effect
4O2-Hb
H-Hb
CO2
diffusion
O2
TISSUE CELLS
CAPILLARY ENDOTHELIUM
28
CARBON DIOXIDE IN THE LUNGS
CAPILLARY ENDOTHELIUM
HCO3-
ALVEOLUS
CO2
Total 7 from plasma 23 from globin 70 from
bicarbonate
CO2
Cl-
diffusion
carbonic anhydrase
H HCO3- ? H2CO3 ? H20 CO2
O2
4O2-Hb
H-Hb
diffusion
98.5 O2 goes to Hb
1.5 O2 dissolved in plasma
29
CONTROL OF RESPIRATION 1
Respiratory centers
in the medulla
ventral respiratory group
inspiratory neurons expiratory neurons
dorsal respiratory group
pontine respiratory group
30
CONTROL OF RESPIRATION 2
Pontine respiratory group Other influences
cerebral cortex limbic system hypothalamus
sleep, exercise, vocalizations, exercise, breath
holding, emotional responses
peripheral and central chemoreceptors (CO2,
H) central chemoreceptors Hering-Breuer
(inflation) reflex proprioceptors pain receptors
pontine respiratory group
ventral respiratory group
dorsal respiratory group
altered patterns of breathing
31
HYPERVENTILATION AND HYPOVENTILATION
What would be the net effect of hyperventilation?
reaction shifts to the left increased H used to
reform carbonic acid used to reform CO2 pH
increases increased CO2 lost from the body
What would be the net effect of hypoventilation?
reaction shifts to the right as CO2 accumulates
in the body H accumulate in the body pH decreases
32
NEGATIVE FEEDBACK CONTROL
33
HYPOXIA AND POSITIVE FEEDBACK
end