Summary Intro to Respiratory system

Respiratory system
- Oxygen is required for cellular respiration
- CO2 is a product of nutrient breakdown
- Functions:
o Obtains oxygen from the atmosphere and removes CO2 from body cell
o Consists tube that filter, warm and moisturize incoming air
o Transport air to gas exchange area

- Other jobs:
o Removes particles from incoming air
o Regulates temperature and water content
o Regulates blood pH
o Provides vocal sounds

How does it work?
- Ventilation or breathing – movement of air into and out of lungs
- External respiration – gas exchange between lung and blood
- Gas transport – occurs between lungs and body cells
- Internal respiration – gas exchange between the blood and body cells
- Cellular respiration – oxygen use by body cells and production of carbon
dioxide

Organs of the respiratory system
- Upper respiratory tract
o Nose – provide opening for entrance and exit of air; contain hair to
prevent entry of particles
o Nasal cavity – line with mucus, trap particle, carry to pharynx by
cilia to the stomach
o Sinuses – air filled spaces; reduce the weight of the skull, serve as
resonant chambers for the voice
o Pharynx (Throat) – common passageway for air and food from nasal and oral
cavities; Aids in producing sounds for speech
 Nasopharynx – only air supposed to pass though
 Oropharynx – air and food pass though
 Laryngopharynx – air and food pass though
- Lower respiratory tract
o Larynx – contain vocal cords, sorting – keep particle from
entering the trachea
 Glottis

,  True vocal cords and opening between them
 There are 2 vocal cords
 False vocal cords – No sound production
 True vocal cords – Sound production
 Larger cartilages of the larynx:
 Thyroid cartilage (Adam’s apple)
 Cricoid cartilage
 Epiglottic cartilage

o Trachea
 Splits into right and left primary bronchi
 Inner wall is lined with ciliated mucous membrane with
many goblet cells
 Support by 20 incomplete (C-shaped) cartilaginous rings that
keep the airway open

o Bronchial tree
 Main bronchi – first branches directly off the trachea
 Lobar bronchi – branches of the main bronchi
 Segmental bronchi
 Bronchioles – absent cartilage
 Terminal bronchioles – smallest bronchioles that conduct air
 Respiratory bronchioles
 Alveolar ducts – branch off respiratory bronchioles
 Alveolar sacs – consist of air sacs called alveoli
 Alveoli – sites of gas exchange between air and blood

o Lungs
 Soft, spongy, cone shaped organs of the respiratory system
 Separated medially by the mediastinum and enclosed by the diaphragm
and thoracic cage
 Occupy most thoracic cavity
 Right lungs have 3 lobes and left has 2 lobes
 Each lung containers air passages, alveoli, nerves, blood vessels,
lymphatic vessels, and connective tissues
 The pleura:
 A double layered serous membrane
 Visceral pleura: inner layer; attached to the surface of each lung,
touching the organ