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