ANATOMY & PHYSIOLOGY
Respiratory System
Functions of the Respiratory System
Gas Exchange
Organs of the Respiratory System
Upper Respiratory Tract Nose Pharynx Larynx
Lower Respiratory Tract Trachea Bronchi Lungs
Nose
framework composed of bone & cartilage2 nostrils called: external nares
where air enters the nasal cavity rt & lt separated by nasal septum
site of nose bleeds@ internal edge: internal nares
Pharynx
throat 3 divisions:1. Nasopharynx
begins @ internal nares end of soft palate
2. Oropharynx edge of soft palate hyoid bone
3. Laryngopharynx hyoid bone upper edge of esophagus
3 Parts of the Pharynx
Larynx
“voice box”CartilageParts:
Epiglottis Glottis Thyroid cartilage Cricoid cartilage
Larynx
moves upward when you swallow tips epiglottis over the glottis (opening of
trachea) allows food esophagus (--/ down trachea to
lungs) if not swallowing: glottis is open allowing air
lungs
http://www.linkstudio.info/images/portfolio/medani/Swallow.swf
Trachea
“windpipe”
Trachea
rings of cartilage maintain its shape to prevent it from closing
forks into 2 bronchi
Bronchus
each enters a lung where it branches into smaller & smaller bronchioles resembling an inverted tree
Bronchioles
fine tubes that allow passage of airsmooth muscle surrounds them when
contracts airways constrictepithelium covered with cilia & mucus
mucus traps dust, particulates cilia beat upward removing trapped particles
from airways (moves particles ~1-3 cm/hr)
Bronchioles
Gas Exchange in Lungs
Gas Exchange in Lungs
Pulmonary Function Tests
“PFTs”subject breathes into a closed system in
which air is trapped w/in a bell floating in water
bell moves up when patient exhales / down when they inhale
Pulmonary Function Tests
Tidal Volume: amt of air expired
Vital Capacity: max amt of air that
can forcefully exhaled after a max inhalation
Spirogram
Anatomical Dead Space
not all inspired air will get into lungs exhaling does not force all air out of the
body
Hemoglobin
helps transport oxygen, carbon dioxide, & buffer blood
as carbon dioxide leaves cells & diffuses thru interstial fluid then into capillary it combines with water to form carbonic acid
Hgb Loading & Unloading Oxygen
Respiratory pH Balance
Respiratory Acidosis
hypoventilation accumulation of CO2
in tissuespH decreasesplasma HCO3-
increases
Respiratory Alkalosis
hyperventilationexcessive loss of CO2pH increasesplasma HCO3-
decreasesCO2 in blood
increases