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 & cartilage 2 nostrils called: external nares  where air enters the nasal cavity  rt & lt separated by nasal septum  site of nose internal edge: internal nares

Pharynx throat 3 divisions: 1. Nasopharynx  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  wallow.swf wallow.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 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

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 CO 2 in tissues pH decreases plasma HCO 3- increases

Respiratory Alkalosis hyperventilation excessive loss of CO 2 pH increases plasma HCO 3- decreases CO2 in blood increases