The Respiratory System
Major functions of the respiratory system
anatomy of the respiratory system
organs of the respiratory system & their location
differences between the right & left lung and right & left primary bronchi
breathing mechanism
definitions of lung capacity terminology
internal and external respiration
disorders of the respiratory system
upper respiratory tract
lower respiratory tract
nose
nasal cavity
paranasal sinuses
pharynx (throat)
gas exchanges between blood and external environment
passageways to lungs purify, warm, and humidify the incoming air
air enters nose through external nares (nostrils)
nasal cavity (inferior of nose) divided by nasal septum
cavities within bones
olfactory receptors (sense of smell) located in mucosa on superior surface
rest lined with respiratory mucosa
lateral walls have conchae
frontal, sphenoid, ethmoid, and maxillary bone
muscular passage from nasal cavity to larynx
3 regions of the pharynx
nasopharyx
superior region behind nasal cavity
oropharynx
middle region behind mouth
laryngopharynx
inferior region attached to larynx
trachea (windpipe)
connects larynx with bronchi
lined with cilitated mucosa
primary bronchi
formed by division of trachea
enters the lungs at hilus
right bronchus is wider, shorter, and straighter than the left due to the presence of the heart of the left side
lungs
occupy most of thoracic cavity
apex is near clavicle
base rests on diaphragm
each lung is divided into lobes by fissures
conducting zone
passage way for gas
primary bronchi, secondary bronchi, tertiary bronchi, bronchioli, and terminal bronchioli
respiratory zone
alveolar duct- branch from bronchioles
alveoli - out-pounching of alveolar duct
gas exchange
between alveoli and capillaries
oxygen enters blood and carbon dioxide enters alveoli
larynx
between pharynx and trachea
air to pass through it while keeping food and drink from blocking the airway
epiglottis
behind the tongue, at the top of the larynx
to seal off the windpipe during eating
middle lobe
between the upper and lower lobe
bringing oxygen into the bloodstream and removing carbon dioxide
superior lobe
above the left lung
the right lung has 3 lobes and the left lobe only has two lobes
respiration
entire process of exchanging gases between atmosphere and body cells
breathing or ventilation
cellular respiration occurs in the mitochondrion of the cell
internal respiration- exchanges of gases between blood and body cells
pulmonary ventilation
movement of air in lungs; depends on pressure gradient
inspiration- flow of air into the lungs
expiration- air leaving lungs
inspiration
increase size of thoracic cavity and decrease pressure
diaphragm moves down
moves ribs up and sternum forward
forced inhalation- scalenes muscles, sternocleidomastoid, and pectoralis minor
expiration
passive process- diaphragm and rib muscles relax
elastic recoil of stretched elastic fibers of lungs and decreases lung volume and increase pressure, forcing air out of lungs
forced expiration- requires contraction of intercostal muscles and abdominal muscles
inspirational capacity- tidal volume + inspiratory reserve volume
functional residual capacity- residual volume + expiratory reserve volume
vital capacity- inspiratory reserve volume + tidal volume+ expiratory reserve volume
total lung capacity- sum of all volumes
chronic obstructive pulmonary disease
history of smoking
labored r difficulty of breathing
coughing and frequent pulmonary infections
hypoxic and leads to respiratory failure
major causes of death
emphesyma
alveoli enlarge as adjacent chambers break through
chronic inflammation promotes lung fibrosis
patients use large amount of energy to exhale
barrel chest
cyanosis late in disease
chronic bronchitis
mucosa becomes inflamed
mucus production increases
pooled mucus impairs ventilation and gas exchange
risk of lung infection increases
lung cancer
1/3 of all cancer deaths
associated with smoking
3 common types - squamos cell carcinoma, small cell carcinoma, and arenocarcinoma
sudden infant death syndrome
unexplained infant death
causes may be due to neural respiratory control center or abnormal heart rhythm
asthma
chronic inflammed hypersenstitive bronchiole passages
response to irritants with dyspnea, coughing, and wheezing
birth defects
cystic fibrsis- oversection of thick mucus clogs the respiratory system
aging effects
elasticity of lung decreases
vital capacity decreases
blood oxygen levels decrease
stimulating effects of carbon dioxide decreases
more risks of respiratory tract infection
respiratory rates
newborns- 40 to 80 respirations per minute
infants- 30 respirations per minute
age 5- 25 respirations per minute
adults- 12 to 18 respirations per minute
rate often increases with old age
upper respiratory tract- nose, nasal cavity, paranasal sinuses, and pharynx
lower respiratory tract- larynx, trachea, bronchial , and lungs
inspiration
diaphragm moves down
flow of air into lung
increased size of thoracic cavity and decreases pressure
moves ribs up and sterum forward
expiration
air leaving lung
decreases lung volume and increases pressure, forces air out of lung
elastic recoil of stretched elastic fibers of lungs
passive process- diaphragm and rib muscles relax