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Jessie Castro P.2 Respiratory System - Coggle Diagram
Jessie Castro P.2 Respiratory System
Internal vs. external respiration
Internal
involves capillary gas exchange in body tissues
External
involves the exchange of O2 and CO2 across respiratory membranes
steep partial pressure gradient for O2 exists between blood and lungs
venous blood PO2 = 40 mm Hg
alveolar PO2 = 104 mm Hg
drives oxygen flow into blood
Volume and Pressure relationships in thoracic cavity
INTRAPULMONARY PRESSURE (Ppul)
pressure in alveoli
fluctuates w/ breathing
always eventually equalizes w/ Patm
TRANSPULMONARY PRESSURE (Ppul - Pip)
pressure that keeps lung spaces open
prevents lung from collapsing
ATMOSPHERIC PRESSURE (Patm)
pressure exerted by air surrounding the body
760 mm Hg at sea level = 1 atmosphere
INTRAPLEURAL PRESSURE (Pip)
pressure in pleural cavity
fluctuates w/ breathing
always negative pressure (<Patm & <Ppul)
2 INWARD FORCES PROMOTE LUNG COLLAPSE
lungs recoil; because of elasticity, lungs always assume smallest size
surface tension pulls on alveoli to reduce alveolar size
1 OUTWARD FORCE ENLARGES LUNGS
elasticity of chest wall pulls thorax outward
Layers of the pleurae
parietal pleura: membrane on thoracic wall, superior face of diaphragm,around heart, and between lungs
visceral pleura: membrane on external lung surface
:
peural fluid: fills slitlike pleural cavity between two pleurae; provides lubrication & surface tension that assists in expansion & recoil of lungs
pleurae: thin, double-layered serosal membrane; divides throracic cavity into 2 pleural compartments & mediastinum
Disorders of the respiratory system
TUBERCULOSIS
bacterial infection in respiratory system caused by mycobacterium tuberculosis
causes: contagious, inhaled, weakened immune system, drug/ alcohol abuse
symptoms: cough w/ thick mucus, weight loss/ night sweats, fever & fatigue
treatment: long-term antibiotics, surgery, medication
COPD
chronic obstructive pulmonary disorder; includes chronic bronchitis, emphysema, and asthma
causes: asthmatic bronchitis, tobacco smoke, dust exposure
symptoms: chronic cough, shortness of breath, wheezing
treatment: smoking cessation, medication, bronchodilators
PNEUMONIA
bacterial/ viral infection of the lungs
causes: bacterial infection, viral infection, aspiration
symptoms: fever, shortness of breath, chills
treatment: over the counter medication, antibiotics, oxygen therapy
LUNG CANCER
uncontrolled cell growth & development of tumors in lungs
causes: smoking, second-hand smoke, asbestos exposure
symptoms: chest pain, shortness of breath, blood in septum
treatment: radiation, chemotherapy, surgical removal
SEASONAL FLU
a viral infection; there are many variations of this virus and it changes
rapidly year to year which changes the severity of symptoms
causes: inhaled in respiratory droplets, age, occupation
symptoms: dry cough, fatigue, congestion
treatment: early vaccination, over the counter medication, rest & hydration
Lower respiratory structures and functions
larynx
connects pharynx to trachea
has framework of cartilage & dense CT
opening can be closed by epiglottis/ vocal folds
air passageway; prevents food from entering lower respiratory system
houses vocal folds
voice production
trachea
runs from larynx & divides into 2 main bronchi
walls contain C-shaped cartilages that are incomplete posteriorly
air passageway; clean, warms, moistens incoming air
bronchial tree
right/ left bronchi; subdivide within lungs to form lobar & segmental bronchi/ bronchioles
air passageways connecting trachea w/ alveoli; cleans, warms, moistens incoming air
alveoli
microscopic chambers
walls of simple squamous EP overlie thin basement membrane
main sites of gas exchange
special alveolar cells produce surfactant (reduces surface tension; helps prevent lung collapse
lungs
composed of alveoli & respiratory passageways
stroma is elastic CT, allowing lungs to recoil during expiration
house respiratory passages smaller than main bronchi
pleurae
serous membranes
parietal pleura lines thoracic cavity; visceral pleura covers external lung surfaces
produce lubricating fluid & compartmentalize lungs
Respiratory volumes and capacities
Volumes
tidal volume (TV): amount of air moved into/ out of lung with each breath (avg. 500ml)
inspiratory reserve volume (IRV): amount of air inspired forcibly beyond tidal volume (2100–3200ml)
expiratory reserve volume (ERV): amount of air forcibly expelled from lungs (1000–1200ml)
residual volume (RV): amount of air that always remains in lungs (needed to keep alveoli open)
Capacities
inspiratory capacity (IC): sum of TV + IRV
functional residual capacity (FRC): sum of RV + ERV
vital capacity (VC): sum of TV + IRV + ERV
total lung capacity (TLC): sum of all lung volumes (TV + IRV+ ERV + RV)
Major functions of the respiratory system
RESPIRATORY SYSTEM
pulmonary ventilation (breathing): movement of air into/ out of lungs
External respiration: exchange of O2 & CO2 between lungs/ blood
CIRCULATORY SYSTEM
Transport of O2 & CO2 blood
Internal respiration: exchange of O2 & CO2 between systemic blood vessels/ tissues
functions: supply body with O2 for cellular respiration & dispose of CO2
Compare/ contrast the mechanism of inspiration and expiration
inspiration: gases flow into lungs
diaphragm contracts, moving inferiorly & flattens out
results in increase in thoracic volume
external intercostals contract, lifting rib cage up & out
as thoracic cavity volume increases, lungs are stretched
causes intrapulmonary pressure to drop
forced inspiration occurs during exercise/ in people w/ COPD
accessory muscles act to increase thoracic cage size, creating larger pressure gradient so more air is drawn
expiration: gases exit lungs
quiet expiration= passive process
inspiratory muscles relax, thoracic cavity volume decreases, lungs recoil
Ppul > Patm so air flows out of lungs down pressure gradient until it's equal
forced expiration: active process that uses oblique/ transverse abdominal muscles, intercoastal muscles
Upper respiratory structures and functions
UPPER RESPIRATORY
pharynx
passageway connecting nasal cavity to larynx & oral cavity to esophagus
nasopharynx: air passageway posterior to nasal cavity
oropharynx: passageway for food/ air from level of soft palate to epiglottis
laryngopharynx: passageway for food and air
facilitates exposure of immune system to inhaled antigens
paranasal sinuses
mucosa-lined, air-filled cavities in cranial bones surrounding nasal cavity
lighten skull, secrete mucus & warm, moisten, filter incoming air
nasal cavity
internal divided by midline nasal septum & lined w/ mucosa
roof contains olfactory epithelium
receptors for sense of smell
external nose
jutting external portion supported by bone & cartilage
nostrils bounded laterally by alae
nose
provides airway for respiration
moistens/ warms entering air
filters/ cleans inspired air
serves as resonating chamber for speech
houses olfactory receptors