Respiratory Intro

Thoracic cage

Framework of ribs sternum and vertebrae that protects lungs and supports respiration

True ribs

Ribs 1 to 7 directly attach to sternum via costal cartilage

False ribs

Ribs 8 to 10 attach indirectly to sternum

Floating ribs

Ribs 11 and 12 with no anterior attachment

Sternum parts

Manubrium body and xiphoid process

Sternal angle

Landmark at rib 2 articulation dividing superior and inferior mediastinum

Thoracic apertures

Superior and inferior openings of thoracic cavity allowing passage of structures

Intercostal muscles

External internal and innermost muscles that aid in breathing

External intercostals

Elevate ribs during inspiration

Internal intercostals

Depress ribs during forced expiration

Neurovascular bundle

Intercostal vein artery and nerve located in costal groove

Diaphragm

Primary muscle of respiration increasing vertical thoracic dimension

Phrenic nerve

Innervates diaphragm C3 C4 C5 keep diaphragm alive

Pump handle movement

Increases anterior posterior diameter of thorax during inspiration

Bucket handle movement

Increases transverse diameter of thorax

Pleura

Serous membranes surrounding lungs

Visceral pleura

Covers lung surface

Parietal pleura

Lines thoracic cavity

Pleural cavity

Potential space with fluid allowing frictionless movement

Pleural recesses

Spaces where lungs expand during inspiration such as costodiaphragmatic recess

Pneumothorax

Air in pleural space causing lung collapse

Thoracocentesis

Procedure to remove fluid from pleural cavity

Trachea

Airway with C shaped cartilage rings conducting air to bronchi

Carina

Point where trachea bifurcates into main bronchi

Right main bronchus

Shorter wider more vertical bronchus

Left main bronchus

Longer narrower more horizontal bronchus

Lobar bronchi

Secondary bronchi supplying lung lobes

Segmental bronchi

Tertiary bronchi supplying bronchopulmonary segments

Right lung

Three lobes superior middle inferior

Left lung

Two lobes superior and inferior

Hilum

Region where bronchi vessels and nerves enter lung

Bronchopulmonary segments

Functionally independent lung units supplied by segmental bronchi

Pulmonary arteries

Carry deoxygenated blood to lungs

Pulmonary veins

Carry oxygenated blood to heart

Sympathetic innervation

Bronchodilation vasoconstriction decreased secretions

Parasympathetic innervation

Bronchoconstriction vasodilation increased secretions

Respiratory epithelium

Pseudostratified ciliated columnar epithelium lining conducting airways

Alveolar epithelium

Simple squamous epithelium for gas exchange

Conducting portion function

Air conduction warming moistening and filtering

Respiratory portion function

Gas exchange with large surface area

Nasal cavity

Filters warms and humidifies incoming air

Olfactory epithelium

Specialized epithelium for smell in superior nasal cavity

Pharynx

Passageway connecting nasal oral cavities to larynx and esophagus

Larynx

Airway structure for phonation and airway protection

Epiglottis

Prevents food from entering airway during swallowing

Tracheal structure

Contains C shaped cartilage rings and respiratory epithelium

Bronchial tree branching

Progressive branching from bronchi to bronchioles increasing surface area

Bronchioles

Small airways lacking cartilage and glands

Terminal bronchioles

End of conducting zone lined by cuboidal cells

Clara cells

Non ciliated cells that secrete protective substances and detoxify

Respiratory bronchioles

Start of respiratory zone where gas exchange begins

Alveolar ducts

Passages leading to alveolar sacs

Alveolar sacs

Clusters of alveoli

Alveoli

Thin walled air sacs for gas exchange

Alveolar type I cells

Thin cells covering 95 percent of surface for gas exchange

Alveolar type II cells

Produce surfactant to reduce surface tension

Surfactant

Substance that prevents alveolar collapse by lowering surface tension

Alveolar macrophages

Remove debris and pathogens from alveoli

Pores of Kohn

Connections between alveoli allowing airflow

Alveolar septum

Thin barrier between alveoli containing capillaries

Blood air barrier

Formed by type I cells fused basal lamina and capillary endothelium

Pleural fluid

Serous fluid reducing friction during breathing

Lung volumes

Individual measurable volumes of air in lungs

Lung capacities

Combinations of two or more lung volumes

Tidal volume

Volume of air inhaled or exhaled during normal breathing about 500 mL

Inspiratory reserve volume

Additional air that can be inhaled after normal inspiration

Expiratory reserve volume

Additional air that can be exhaled after normal expiration

Residual volume

Air remaining in lungs after maximal expiration not measured by spirometry

Vital capacity

Maximum air exhaled after maximal inspiration

Total lung capacity

Total volume of air in lungs including residual volume

Spirometry

Method used to measure lung volumes and capacities

Helium dilution

Method to measure residual volume using gas equilibration

Body plethysmography

Method measuring lung volumes using pressure changes in sealed box

Compliance

Measure of lung expandability change in volume per pressure

High compliance

Lungs expand easily seen in obstructive disease

Low compliance

Stiff lungs seen in restrictive disease

Restrictive lung disease

Decreases lung volumes and total lung capacity less than 80 percent

Obstructive lung disease

Airflow limitation with increased total lung capacity greater than 120 percent

Air trapping

Incomplete emptying of lungs in obstructive disease

Forced vital capacity

FVC maximum volume exhaled forcefully after inspiration

FEV1

Volume exhaled in first second of forced expiration

FEV1 to FVC ratio

Used to differentiate obstructive less than 70 percent and restrictive greater than 70 percent

Minute ventilation

Total air moved per minute tidal volume times respiratory rate

Alveolar ventilation

Air reaching alveoli equal to tidal volume minus dead space times rate

Physiologic dead space

Sum of anatomical and alveolar dead space

Alveolar ventilation equation

Relates alveolar ventilation to carbon dioxide levels

Relationship of ventilation and CO2

Inverse relationship increased ventilation decreases alveolar CO2

Hyperventilation

Increases alveolar oxygen and decreases carbon dioxide

Hypoventilation

Decreases oxygen and increases carbon dioxide

Alveolar gas equation

Calculates alveolar oxygen based on inspired oxygen and carbon dioxide levels