Respiratory System
Rose Bui-Luu, Period 2
Major Functions
Upper Respiratory
Lower Respiratory
Structure
Function
Structure
Function
Layers of Pleurae (double-layered serous membrane)
Volume & Pressure Relationships in Thoracic Cavity
Respiratory Volumes & Capacities
Disorders
Internal vs. External Respiration
Mechanism of Inspiration & Expiration
obtains O2 from atmosphere, removes CO2 from the body cells
helps in sense of smell
removes particles from incoming air
regulates water content and the temperature of the air
provides vocal sounds
regulates blood pH
consists of tubes that filter, warm, moisturize incoming air, and transport it into the gas exchange areas and microscopic air sacs that exchange gases
larynx (voice box)
trachea
bronchial tree
lungs
Nose
Nasal Cavity
Sinuses
Pharynx (throat)
nostrils provide opening for entrance + exit of air
support mucous membranes and increase surface area to warm, moisturize, and filter incoming air
reduce weight of the skull, serves as resonant chambers for the voice
aids in producing sounds for speech
air-filled spaces in maxillary, frontal, ethmoid, and sphenoid bones
open into the nasal cavity
lined with mucous membrane that is continuous with that lining the nasal cavity
space being oral + nasal cavities and larynx
3 subdivisions: nasopharynx, oropharynx, laryngopharynx
(<- superior ... inferior ->)
supported by bone and cartilage
nostrils contain coarse hairs, which prevent entry of particles
hollow space posterior to nose
divided medially by nasal septum (wall), consisting of bone and cartilage)
nasal conchae, scroll-shaped bones, divide nasal cavity into passageways
an enlargement in airway superior to trachea and inferior to laryngopharynx
composed of framework of muscles and cartilage bound by elastic tissue
larger cartilage of larynx in men = thyroid cartilage (adam's apple)
transport air in and out of trachea, helps keep particles from entering trachea, houses vocal cords
vocal folds: consists of muscle and connective tissue, covered with mucous membrane, extend from the walls
Epiglottis
Glottis
true vocal cords and opening between them
flaplike, made of elastic cartilage; covers opening to glottis
cylindrical tube that extends downward anterior to esophagus and into thoracic cavity
splits into right/left primary bronchi
inner wall lined with ciliated mucous membrane with many goblet cells that produce mucus to trap incoming particles, cilia sweeps mucus toward pharynx to be swallowed
wall supported by 20 incomplete (c-shaped) cartilaginous rings that keep airway open
consists of branched, mucous membrane-lined tubular airwars, leading from trachea to microscopic air sacs of lungs called alveoli
branches
alveoli: consist of simple squamous epithelium to conduct rapid gas exchange between air and blood with associated capillaries; closley surrounded by extensive capillary networks
primary bronchi: first branches; branch directly off trachea, each leads to a lung
secondary bronchi: branches of main bronchi; each enters lobe of a lung
tertiary bronchi: branches of lobar bronchi; each enters segment of a lung
alveolar ducts: branch off respiratory bronchioles
alveolar sacs: branch of alveolar ducts; consist of air sacs (alveoli)
Bronchioles: smaller tubular organs that branch of segmented bronchi
Terminal Bronchioles: branch of larger bronchioles; smallest bronchiole that conduct air without performing gas exchange
soft, spongy cone-shaped organs of respiratory system
separated medially by mediastinum, enclosed by diaphragm and thoracic cage
occupies most of thoracic cavity
Visceral Pleura: inner layer; attached to surface of each lung
Parietal Pleura: outer layer; lines thoracic cavity
Serous Fluid: lubricates pleural cavity between the 2 layers
right lung larger than left
right = 3 lobes (superior, middle, inferior)
left = 2 lobes (superior, inferior)
each lung contains air passages, alveoli, nerves, blood vessels, lymphatic vessels, connective tissues
conduct air from trachea to alveoli; mucous lining continues to filter incoming air
passageway for air; mucous lining continues to filter particles from incoming air
contain air passages, alveoli, blood vessels, connective tissues, lymphatic vessels, nerves
Volumes
Capacities (combos of 2+ Volumes)
Tidal Volume (TV)
Inspiratory Reserve Volume (IRV)
Expiratory Reserve Volume (ERV)
Residual Volume (RV)
Inspiratory Capacity (IC)
Vital Capacity (VC)
Functional Residual Capacity (FRC)
volume of air that remains in lungs after maximal expiration; average ≈ 1,200 mL; can't be measured with spirometer
volume of air that can be inhaled in addition to TV during forced inspiration; average ≈ 3,000 mL
volume of air that enters/leaves lungs during respiratory cycle; average ≈ 500 mL
volume of air that can be exhaled during maximal forced expiration, beyond the TV; average ≈ 1,200 mL
volume of air that can be inhaled after normal, resting expiration; IRV + TV (≈3,500 mL)
volume of air that remains in lungs after a resting expiration; ERV + RV (≈2,300 mL)
maximum volume of air that can be exhaled after a maximal inspiration; TRV + IRV + ERV (≈4,600 mL)
Total Lung Capacity (TLC)
total volume of air the lungs can hold; VC + RV (≈5,800 mL); varies with age, gender, body size
Anatomic Dead Space
volume of air remaining in bronchial tree that isn't involved in gas exchange
Tuberculosis: bacterial infection in the respiratory system caused by Myobacterium Tuberculosis
COPD: Chronic Obstructive Pulmonary Disorder; includes chronic bronchitis, emphysema, and asthma
Causes/Risk Factors: asthmatic bronchitis, tobacco smoke, dust and chemical fume exposure
Symptoms: chronic cough, wheezing lung damage
Treatment Options: smoking cessation, bronchodilators, pulmonary rehabilititation
Causes Risk Factors: contagious inhaled, travel where TB is common, care/live with TB patients
Symptoms: latent TB-asymptomatic, swollen lymph nodes, cough with thick mucus
Treatment Options: long-term antibiotics: surgery, medication (some drug-resistant variations can't be treated)
Pneumonia: bacterial or viral infection of the lungs
Causes/Risk Factors: exposure to infected individuals, complication with other respiratory infections, impaired immune system
Symptoms: fever, shortness of breath, tachycardia
Treatment Options: over the counter medication, antibiotics, oxygen therapy
Lung Cancer: uncontrolled cell growth and undeveloped tumors in the lungs
Causes/Risk Factos: smoking (90% of cases), asbestos exposure, radon gas
Symptoms: blood in sputum, persistent cough, chronic infections
Treatment Options: radiation, chemotherapy, surgical removal; at later stages, treatments only prolong life not cure disease
Seasonal Flu: a viral infection; there are many variations of this virus and it changed rapidly year to year which changes severity of symptoms
Causes/Risk Factors: inhaled in respiratory droplets, living conditions, pregnancy
Symptoms: dry cough, congestion, body ache
Treatment Options: early vaccination, over the counter or antiviral medication, rest and hydration
more commen in men and most common at ages 75-84
highest cases in the world in Azerbaijan by 22%
every 1 in 5 of 8.8 million child deaths due to TB
highest case of lung cancer in the US is in the South, perhaps due to higher amount of pollution or tobacco usage
359 cases of H1N1, a strain of flu, found in San Diego County by 2009
Internal Respiration
External Respiration
gas exchange between BLOOD and BODY CELLS
gas exchange between LUNGS and BLOOD
Inspiration (inhalation)
Expiration (exhalation)
air moves from higher to lower pressure
Inspiration
pressure inside lung decreases below AP, air flows in
increasing volume of thoracic cavity, air pressure inside lungs decreases
diaphragm + external intercostal muscles CONTRACT, pressure in lungs fall 2 mm below AP, air rushes into lungs
Expiration
diaphragm + external intercostal muscles RELAX, lungs recoil, volume of thoracic cavity decreases
passive process
increased surface tension in alveoli decreases lung volume
intra-alveolar pressure increases 1 mm Hg above AP, air rushes out of lungs
active process
Normal Inspiration
diaphragm + external intercostal muscles expand thoracic cavity
diaphragm contracts + moves downward, enlarging TC
external intercostals contract, moving ribs + sternum upward and outward
Maximal Inspiration
pectoralis minor, sternocleidomastoid, scalenes, diaphram, exernal intercostal muscles required to enlarge TC even more
surface tension between double pleura causes TC + lungs to expand
surface tension not advantageious in alveoli, tends to cause alveolar collapse
lipoprotein mixture -> surfactant; keeps alveoli inflated to prevent collapse
elastic recoil of muscles + lung tissues from surface tension within alveoli
diaphragm recoils -> abdominal organs return to OG shape, pushing diaphragm upward
lungs recoil -> pleura + chest wall pulled inward
air rushes out of lungs
Forced Expiration
allows for expiration of more air than normal
aided by internal intercostal muscles + abdominal wall muscles, which compress rib cage + addominal wall respectively