Download Respiratory System

Respiration
And the Pulmonary System
Types of Respiration

Pulmonary respiration
(ventilation) – Breathing
– Inspiration
– Expiration



External respiration –
between lungs and blood
Internal respiration –
Between blood and cells
Cellular respiration
Glucose + Oxygen 
Carbon Dioxide and water
and energy.
Organization of Respiratory
Organs

By location
– Upper respiratory
system


Nose
Pharynx and associated
structure
– Lower respiratory
system



Larynx
Bronchial tree
Lungs

By function
– Conducting portion
 Nasal passageways
 Pharynx
 Larynx
– Respiratory portion
 Bronchial tree – Bronchi
 terminal bronchiole
 Respiratory bronchioles
 Alveolar ducts
 Alveoli
Nose

Components

–
–
–
–
– External




Nasal bones
Alar cartilage
External nares – Nostils
Nasal septum
– Internal


Choanae
Internal nares
– Mucous membrane
Paranasal sinuses

Frontal
Sphenoidal
Ethmoidal
Maxillary
Functions
– Incoming air
 Warmed
 Moistened
 Filtered
– Olfactory stimuli received
– Sound
 Resonate
 Modification
Pharynx (throat)


Extent
– Internal nares
– Cricoid cartilage
– Oropharynx
 Opening – Fauces
 Tonsils
– Palatine
– Lingual
– Common Path
• Air
• Drink
• Food
(larynx)

Regions
– Nasopharynx

Openings
– Internal nares
– Auditory
(Eustachian) tubes
Pharyngeal tonsil (adenoid)
– Laryngopharynx
(hypopharynx) – Connected
inferiorly


Esophagus
Larynx
Larynx (Part 1)


Joins pharynx to trachea
Cartilages
– 3 unpaired
 Epiglottis
– Protects airway
– Covers glottis


Thyroid – Adam’s apple
Cricoid – Tracheostomy
landmark
– 3 paired
 Arytenoid
 Corniculate
 Cuneiform

Voice production
– Laryngeal mucous
membranes


Ventricular folds (false
vocal chords)– Superior
Vocal folds (true vocal
chords) – Inferior
– Bring folds together


Hold breath against
pressure
Vibrate in response to
pressure
Larynx (Part 2)
– Control


Loudness – Air pressure
Pitch – vocal fold tension
– Resonance


Upper respiratory tract
Paranasal sinuses
– Modifications – Muscles




Pharynx
Face
Tongue
Cheeks
Anatomy of the Larynx
Trachea


Windpipe
Leads from larynx into
bronchial tree
– Sternal angle
– T5
– Carina – Cough reflex

C-shaped cartilage
– Holds trachea open
– Allows esophageal
expansion

Clinical applications
– Tracheostomy
– Intubation
Bronchi (Part 1)


Begin at sternal angle (T5)
Diameter decreases as
branching increases


– Left
 Smaller diameter
 Longer
 More horizontal
– Amount of cartilage
decreases as diameter
decreases
– Amount of smooth muscle
increases as diameter
increases


Secondary (serve a lobe)
– 3 on right
– 2 on left
Primary (serve a lung)
– Right
 Wider diameter
Shorter
More vertical

Tertiary – Segmental or
lobular
Bronchi (Part 2)


Tertiary – Segmental or
lobular
Bronchioles
– Small branches of bronchial
area
– Terminal – Extend into
alveolar clusters
– Respiratory – Extend
directly into alveoli

ANS effects
– Sympathetic --
Bronchodilate
– Parasympathetic -Bronchoconstrict
Lungs (Part 1)

Enclosed by pleurae
– Parietal


– Visceral
– Blood vessels
– Bronchi
– Nerves
– Pleural cavity

Gross anatomy
– Base – fits over diagragm
– Apex – extends into root of
neck
– Costal surface – Lies
against ribs
– Mediastinal surface
Faces heart
Hilus (hilum) –
Entrance/Exit

Right lung
– 3 lobes
• Superior
• Middle
• Inferior
– 2 fissures
Lungs (Part 2)
• Oblique
• Horizontal

Left lung
– 2 lobes
• Superior
• Inferior
– 1 fissure – Oblique
– Cardiac notch
Pulmonary Ventilation - Respiration
(Part 1)



1 respiration = 1
inspiration + 1 expiration
Exchange of gases
between atmosphere and
lungs
Normal inspiration
(inhalation)
– Increase thoracic cavity
volume – Contract


Diaphragm
External intercostals
– Reduction in intrapleural
pressure
– Air rushes into lungs

Forced inspiration
– Body needs more air
exchange
– Need more change in
thoracic cavity volume
– Use additional muscles
to raise thoracic cage



Sterrocleidomastoid
Scalenes
Pectoralis minor
Pulmonary Ventilation - Respiration
(Part 2)

Normal expiration
(exhalation)


– Decrease thoracic cavity
volume
– Diaphragm relaxes
– Intrapleural pressure
increases
– Air pushed out of lungs

Forced expiration
– Body needs more air
exchange
– Active process using

Abdominal muscles
Internal intercostals
Factors affecting ease of
respiration
– Compliance
 Elasticity
– Surface tension –
Surfactant


Airway resistance
Modified respirations
–
–
–
–
Cough
Sneeze
Sigh
Yawn
Pulmonary Ventilation - Respiration
(Part 3)
– Laugh
– Hiccuping

Related terminology
– Hyperventilation
– Hypoventilation
– Eupnea
– Dyspnea
– Apnea
– Shortness of Breath (SOB)
– Atelectasis
Lung Histology


Lung – Lobe – Segment –
Lobule – Alveoli
Alveolus
– Respiratory membrane
– Components
 Alveolar wall
 Epithelial basement
membrane
 Capillary basement
membrane
 Capillary endothelial
– Thickness – 0.5 microns
– Allows fast exchange of
– Epithelial “bubble”
 Type I cells – lining
 Type II cells – surfactant
– Alveolar macrophages
– Monocytes
– Fibroblasts

Alveolar capillary
membrane
respiratory gases

Total surface area – 70
square meters (750 square
feet)
Lung Blood Supply

Bronchial
– Arteries
 Bring blood to supply lung
cells
– Veins
 Drain blood from lung
cells
 Drain into azygous system

Pulmonary
– Arteries
 Carry oxygen poor blood
fromR. Ventricle for
perfusion
– Veins

Carry oxygen rich
blood back to L.
ventricle for systemic
circulation
Respiratory Gases in the
Blood

Oxygen
– Very little dissolved in
plasma
– Most bound to
hemoglobin (Hb)


1 O2/heme
4 hemes/Hb
– Hb+O2 HbO2

Carbon dioxide
– Small amount
dissolves in plasma –
More soluble than
oxygen
– Carbaminohemoglobin
– Hb + CO2 
HbCO2
– As bicarbonate ions


CO2+H2OH2CO3
H2CO3H+HCO3
Transport and Exchange of
Carbon Dioxide and Oxygen
Pulmonary Function
Measurements


– Inspiratory reserve volume
1 respiration = 1
inspiration + 1 expiration
Should be
(IRV)
– Expiratory reserve volume
(ERV)
– Residual volume (RV)
– Minimal volume (MV)
– About 12 per minute
– About 6 L per minute


Measure with spirometer
Pulmonary volumes
(specific conditions)
– Tidal volume (TV)
– Minute respiratory volume
(MVR) – TV x respiration
rate

Pulmonary capacities
(combined conditions)
– Inspiratory capacity – TV
+IRV
– Function residual capacity –
RV+ERV
– Vital capacity – IRV+TV
+ERV
– Total capacity –
TV+IRV+ERV+RV+MV
Control of Respiration (Part 1)

Respiratory centers
– Medullary rhythmicity

Areas
– Inspiration
– Expiratory

Sets basic rhythm
– 2 sec inspiration
– 3 sec expiration

Communicate with
diaphragm
– Phrenic n.
– Intercostal n.
– Pons
 Helps switch between
inspiration/expiration
 Areas
– Pneumotaxic
• Limits inspiration
• Overrides
apneuistic area
– Apneuistic
– Limits expiration
• Stimulates
inspiration
• Works when
pneumotaxis area
is inactive
Control of Respiration (Part 2)

Influencing factors

– Aortic body
– Carotid body
– Vagus n.


Bronchial stretch
receptors – Inflation
reflex
Anal sphincter receptors
– Chemical stimuli

Medulla oblongata –
Central chemoceptors –
H ions
– Peripheral
chemoceptors
Where

What
– H ions
– CO2
– O2
– Proprioceptors
– Increased body temperature
– Pain
 Acute
 Chronic
– Upper respiratory irritation
– Emotional stimuli
– Cortical influences