RespirationRespiration
And the Pulmonary System
Types of RespirationTypes of Respiration
Pulmonary respiration (ventilation) – Breathing– Inspiration– Expiration
External respiration – between lungs and blood
Internal respiration – Between blood and cells
Cellular respirationGlucose + Oxygen Carbon Dioxide and water and energy.
Organization of Respiratory Organization of Respiratory OrgansOrgans
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
NoseNose
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)Pharynx (throat)
Extent– Internal nares– Cricoid cartilage
(larynx)
Regions– Nasopharynx
Openings– Internal nares
– Auditory (Eustachian) tubes
Pharyngeal tonsil (adenoid)
– Oropharynx Opening – Fauces Tonsils
– Palatine
– Lingual
– Common Path
• Air
• Drink
• Food
– Laryngopharynx (hypopharynx) – Connected inferiorly
Esophagus Larynx
Larynx (Part 1)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)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 LarynxAnatomy of the Larynx
TracheaTrachea
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)Bronchi (Part 1)
Begin at sternal angle (T5) Diameter decreases as
branching increases– Amount of cartilage
decreases as diameter decreases
– Amount of smooth muscle increases as diameter increases
Primary (serve a lung)– Right
Wider diameter
Shorter More vertical
– Left Smaller diameter Longer More horizontal
Secondary (serve a lobe)– 3 on right– 2 on left
Tertiary – Segmental or lobular
Bronchi (Part 2)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)Lungs (Part 1)
Enclosed by pleurae – Parietal– Visceral– 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– Blood vessels
– Bronchi
– Nerves Right lung
– 3 lobes
• Superior
• Middle
• Inferior
– 2 fissures
Lungs (Part 2)Lungs (Part 2)
• Oblique
• Horizontal Left lung
– 2 lobes
• Superior
• Inferior
– 1 fissure – Oblique
– Cardiac notch
Pulmonary Ventilation - Respiration Pulmonary Ventilation - Respiration (Part 1)(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 Pulmonary Ventilation - Respiration (Part 2)(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 Pulmonary Ventilation - Respiration (Part 3)(Part 3)
– Laugh– Hiccuping
Related terminology– Hyperventilation– Hypoventilation– Eupnea– Dyspnea– Apnea– Shortness of Breath (SOB)– Atelectasis
Lung HistologyLung Histology
Lung – Lobe – Segment – Lobule – Alveoli
Alveolus– Epithelial “bubble”
Type I cells – lining Type II cells – surfactant
– Alveolar macrophages– Monocytes– Fibroblasts
Alveolar capillary membrane
– Respiratory membrane– Components
Alveolar wall Epithelial basement
membrane Capillary basement
membrane Capillary endothelial
– Thickness – 0.5 microns– Allows fast exchange of
respiratory gases Total surface area – 70
square meters (750 square feet)
Lung Blood SupplyLung 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 Respiratory Gases in the BloodBlood
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+H2OH2CO3 H2CO3H+HCO3
Transport and Exchange of Transport and Exchange of Carbon Dioxide and OxygenCarbon Dioxide and Oxygen
Pulmonary Function Pulmonary Function MeasurementsMeasurements
1 respiration = 1 inspiration + 1 expiration
Should be – 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
– Inspiratory reserve volume (IRV)
– Expiratory reserve volume (ERV)
– Residual volume (RV)– Minimal volume (MV)
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)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)Control of Respiration (Part 2)
Influencing factors– Vagus n.
Bronchial stretch receptors – Inflation reflex
Anal sphincter receptors
– Chemical stimuli Medulla oblongata –
Central chemoceptors – H ions
– Peripheral chemoceptors
Where – Aortic body– Carotid body
What– H ions– CO2– O2
– Proprioceptors– Increased body temperature– Pain
Acute Chronic
– Upper respiratory irritation– Emotional stimuli– Cortical influences