Download Respiratory System

Respiratory System
ANATOMY & PHYSIOLOGY
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 & cartilage
 2 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:
Nasopharynx
1.

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”
 Cartilage
 Parts:
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


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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 air
 smooth muscle surrounds them when contracts
airways constrict
 epithelium 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
tissues
 pH decreases
 plasma HCO3- increases
Respiratory Alkalosis
 hyperventilation
 excessive loss of CO2
 pH increases
 plasma HCO3- decreases
 CO2 in blood increases