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Respiratory System Jessika Lee Period 1 - Coggle Diagram
Respiratory System Jessika Lee Period 1
Layers of pleurae
Pleurae: thin, double-layered serosal membrane that divides thoracic cavity into two pleural compartments and mediastinal
parietal pleura: membrane of thoracic wall, superior face of diaphragm, around heart, and between lungs
Visceral pleura: membrane on external lung surface
Upper respiratory structures and functions
Structures
nose and nasal cavity
para nasal sinuses
pharynx
Functions
the nose is the only external portion
provides airway for respiration
moistens and warms entering air
filters and cleans inspired air
serves as respiratory chamber for speech
houses olfactory receptors
Pharynx
3 regions:
naso pharynx- air passageway posterior to nasal cavity
oropharnyx- passageway for air from level of soft palate to epiglottis
laryngopharynx- passageway for food and air
Lower respiratory structures and functions
Structures
larynx
trachea
bronchi
lungs
broken into 2 zones, respiratory zone and conducting zone
Respiratory zone: site of gas exchange
Conducting zone: transport gas to and from gas exchange sites
Functions
larynx- voice box, provides patent airway, routes air and food into proper channels, houses vocal folds
Trachea- windpipe, extends from larynx into mediastinum, divides into 2 main bronchi
Bronchi- air passageways undergo 23 orders of branching
tips of bronchial tree: conducting zone structures which give rise to respiratory zone structures
trachea divides form right and left bronchi
each main bronchus enters hilum of one lung
Lungs- occupy all thoracic cavity except mediastinum
left lung- superior and inferior lobes by oblique fissure
right lung- superior, middle, inferior lobes
Major functions
supply body with O2 fro cellular respiration
dispose of CO2 waste product of cellular respiration
Involves 4 processes
Pulmonary ventilation: movement of air into and out of lungs
External respiration: exchange of O2 and CO2 between lungs and blood
Inspiration and expiration
Inspiration
active process involving inspiratory muscles, diaphragm and external intercostals
forces inspirations during vigorous exercise
when dome shaped diaphragm contracts, it moves inferior and flattens out
results in increase of thoracic volume - when intercostal muscles contract, rib cage is lifted up and out which results in increase of thoracic volume
as volume increases lungs are stretched as they are pulled out of the thoracic cage
causes intrapulmonary pressure drop
Expiration
quiet normally in passive process
muscle relax, thoracic activity decreases lungs recoil
volume decrease causes intrapulmonary pressure to increase
forced expiration is an active process that uses oblique and transverse abdominal muscles, as well as internal intercostal muscles
Volume and pressure
Atmospheric Pressure: pressure exerted by air surrounding body
760 mm Hg at sea level = 1
intrapulmonary pressure: pressure in alveoli- intra alveolar pressure , fluctuates breathing, always equalizes with Patm
Transpulmonary pressure: pressure keeps lung spaces open, keeps from collapsing
intrapleural pressure: pressure in pleural cavity, fluctuates with breathing, always negative pressure
lungs collapse inward forces
lung's natural tendency to recoil, try to assume smallest size
surface tension pulls on alveoli to try to reduce alveolar size
one outward force tends to enlarge lungs
elasticity pulls thorax out
Respiratory volumes and capacities
Tidal volume: amount air moved into and out of lung with each breath, averages 500 mL
Inspiratory reserve volume: amount of air that can be inspired forcibly beyond tidal volume (2100-3200 mL)
Expiratory reserve volume: amount of air that can be forcibly from lungs (1000-1200 mL)
Residual volume: amount of air that always remains in lungs, need to keep alveoli open
combination of 2 or more respiratory volumes
Inspiratory capacity: sum of TV + IRV
Functional residual capacity: sum of RV + ERV
Vital capacity: sum of TV + IRV + ERV
Total lung capacity: sum of all lung volumes (TV + IRV + ERV + RV)
Internal vs. external respiration
External Respiration
external respiration involves exchange of O2 and CO2 across respiratory membranes
partial pressure gradients and gas solubility
sleep partial pressure gradient fro O2 exits between blood and lungs
drives oxygen into blood
Internal inspiration
involves capillary gas exchange in body tissues
Disorders of the Respiratory system
infected and swollen tonsils can block air passage in nasopharynx, making it necessary to breathe through the mouth
air not properly moistened
when enlarged, speech and sleep may be disturbed
surgery may be necessary
Laryngitis: inflammation of the vocal folds that causes vocal folds to swell interfering vibrations
results un changes of vocal tone, severe cases speaking is limited to whisper
most often caused by viral infection
smoking inhibits and ultimately destroys cilia
Pleuring: inflammation of pleurae results from pneumonia
inflamed pleura become rough, results in friction and stabbing pain