LS week 1- Airways and Breathing

5 functions of respiratory system:

gas exchange= oxygen enters blood and carbon dioxide leaves

regulation of blood pH= altered by changing blood carbon dioxide levels

voice production= movement of air past focal folds create sound and speech

olfcation= smell occurs when airborne molecules drawn into nasal cavity

protection= against microorganisms by preventing entry and removing them

respiratory tract

air passages from nose to the lungs and gas-exchange surfaces

upper respiratory tract

from nose through larynx

• nose

• sinuses= openings from the nasal cavities

• pharynx= throat

• larynx= voice box

epiglottis

a lid at the entry of larynx, which seals the laryngeal opening during swallowing to keep food and liquid out of airway

glottis

vocal cords with opening- airflow through the glottis vibrates the vocal cords and produces sound

lower respiratory tract

from trachea through lungs

• trachea= windpipe

• bronchial tree= series of branching passages that carry air from trachea to gas-exchange surfaces in the lungs

• lungs

• alveoli= gas exchange surfaces

cilia

“mucus escalator”- sweep the mucus and foreign particles upwards toward the throat, away from the lungs

hilum

a slit on mediastinal surface through which it receives bronchi, blood vessels, nerves and lymphatics

plurae

two-layered membrane with fluid in between to allow the lungs to move freely against thoracic wall (visceral and parietal)

respiratory cycle

one complete inspiration and expiration

breathing/pulmonary ventilation

airflow into and out of lungs driven by differences in pressure between the atmosphere and lungs

respiratory muscles:

• diaphragm

• external intercostal muscles

• internal intercostal muscles

difference in airway in child vs adult

• airway is narrower and shorter

• tongue is disproportionally large

• epiglottis is more floppy

obstruction of the airway:

• tongue

• fluids- blood, vomit, mucus

• foreign material- food, toys

• swelling of tissue- infection, burns, anaphylaxis

• external compression- tumor, thyroid, abscess, trauma

pneomothorax

puncture of parietal layer