Chapter 13 Respiratory System Flashcards
Organs of the respiratory system
Nose
Pharynx
Larynx
Traechea
Bronchi
Lungs-alveoli
Functions of Respiratory system
Gas exchangees between blood and external environment occurs in the alveoli of the lungs
passage ways to the lungs purify, humidify and warm the incoming air
help control the bodys pH
Nose
only external visible part of the system
air enters through external nostrils (nares)
interior nasal cavity divided by nasal septum (vomer, ethmoid and cartilage)
Anatomy of nasal cavity
olfactory receptors are located on the superior surface
lined with respiratory mucosa to moisten air and trap foreign particles
lateral walls have projections called conchae to increase surface area and air turbulence in nasal cavity
separated from oral cavity by the palate
anterior hard palate-bone, posterior soft palate-muscle
Paranasal SInuses
air filled cavities with bones surrounding the nasal cavity
located in skull
sinuses function
lighten the skull
resonance chambers for speech
produce mucus that drains into the nasal cavity
Pharynx (throat)
muscular passage from nasal cavity to larynx
three regions
Nasopharynx
Oropharynx
Laryngopharynx
Nasopharynx
superior region behind the nasal cavity
Oropharynx
middle region behind the oral cavity
Laryngopharynx
inferior region attached to the larynx
Oropharynx and Laryngopharynx
common passagways for food and air
Larynx
formed by 8 rigid hyaline cartilages and a flap of elastic cartilage (epiglottis)
Plays role in speech “voice box”
Epiglottis
protects the superior opening of larynx
routes food to the esophogus and air toward the treachea
when swallowing it rises and forms a lid over the opening of the larynx
Voice box
true vocal cords:
vocal folds, lower folds, vibrate with expelled air to create sound (vocalization)
false vocal cords:
vestibular folds, upper cords
Treachea (windpipe)
4” tube that connects larynx with bronchi
walls are reinforced with C-shaped hyaline cartilage
lined with psuedo stratified cilinated columnar epithelium
cilia beat continuously toward pharynx, remove dust and other debris from lungs
Bronchial tree
Primary Bronchi
Secondary Bronchi
Tertiary bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoi
Alveoi
microscopic air sacs
simple squamous epithelium
permits rapid gas exchange
Lungs
soft spongy cone shaped organs
Apex near clavicle (superior portion)
base rests on diaphragm (inferior portion)
divided into lobes by fissures
Left Lung 2 lobes
Right lung 3 lobes
Respiratory Membrane
pulmonary capillaries cover external surfaces of alveoli
O2 and CO2 must cross when moving between alveoli and blood in pulmonary capillaries
three layers:
simple squamous epithelium (alveolar wall)
fused basement membrane
capillary epithelium
Air on one side, blood on the other
Gas exchange
gas diffuses across the respiratory membrane
oxygen enters blood
CO2 enters the alveoli
Events of Respiration
Pulmonary ventilation
external respiration
respiratory gas transport
internal respiration
Pulmonary ventilation
moving air in and out of the lungs
breathing
External respiration
gas exchange between pulmonary blood and alveoli
oxygen is loaded in blood
CO2 is unloaded from blood into alveoli
Respiratory Gas transport
transport of O2 and CO2 via the bloodstream
Internal Respiration
gas exchange between the blood in systemic capillaries and tissue cells
Breathing
completely a mechanical process that depends on volume changes in the thoracic cavity
volume changes lead to pressure changes
2 phases:
inspiration (inhalation)
expiration (exhalation)
Volume changes in breathing
air flows because of a pressure gradient
air flow stops when pressure equalizes
Air flows into or out of lungs due to air pressure gradients
Inspiration (inhalation)
Insparatory muscles contract
lung volume increases
pressure lower in lungs than atmosphere
air flows into lungs
Expiration (exhalation)
Insparatory muscles relax
lung volume decreases
pressure higher in lungs than atmosphere
air flows out of lungs
External respiration
Alveolar Gas exchange
O2:
diffuses from alveoli into blood of pulmonary capillaries
CO2:
diffuses from blood into pulmonary capillaries in alveoli
blood leaves lungs rich in O2 low in CO2
Gas Transport in Blood
Oxygen transported in blood
almost all O2 is transported in blood by hemoglobin (HbO2)
small amount transported in plasma
CO2 transport in blood:
most is transported in plasma as bicarbonite ion (HCO3) 70%
Carbaminlhemoglobin
10% dissolved in plasma
Internal Respiration
exchange of gases between blood and body cells
CO2 diffuses out of tissue into body
Hemoglobin releases O2
O2 diffuses from blood into tissue
Control of Neural Regulation of Respiration
neural centers that control rate and depth are located in the medulla and pons
Medulla: sets basic rythm of breathing
Pons: controls respiratory rate
Respiratory rate and depth influencing factors
CO2 levels in arterial blood:
increased levels of CO2 in crease rate and depth of breathing
O2 levels very very low levels in blood will stimulate breathing
