Please enable JavaScript.
Coggle requires JavaScript to display documents.
Respiratory System Alayna Dixon 3rd Period Anatomy and Physiology -…
Respiratory System
Alayna Dixon 3rd Period Anatomy and Physiology
Major functions of the respiratory system
Consists of tubes that filter, warm, and moisturize incoming air, and transport it into the gas exchange areas, and microscopic air sacs that exchange gases
Other functions of the respiratory system: removes particles from incoming air, regulates temperature and water content of the air, provides vocal sounds, regulates blood pH, and helps in sense of smell
Obtains oxygen from the atmosphere, and removes carbon dioxide from the body cells
Upper respiratory structures and functions
Nasal Cavity
Hollow space posterior to the nose
Divided medially by nasal septum, consisting of bone & cartilage
Nasal conchae are scroll-shaped bones that divide the nasal cavity into passageways
Conchae support mucous membranes, and increase the surface area to warm, moisturize, and filter incoming air
Particles trapped in the mucus are carried to the pharynx by action of cilia,swallowed, and carried to the stomach, where gastric juice destroys microorganisms in the mucus
Paranasal Sinuses
Air-filled spaces in the maxillary, frontal, ethmoid, and sphenoid bones
Sinuses open into the nasal cavity
Lined with mucous membrane that is continuous with that lining the nasal cavity
Reduce the weight of the skull
Serve as resonant chambers for the voice
Nose
Nostrils provide openings for entrance and exit of air
Supported by bone and cartilage
Nostrils contain coarse hairs, which prevent entry of particles
Pharynx
Space behind oral and nasal cavities and larynx
Common passageway for air and food from nasal & oral cavities
Aids in producing sounds for speech
3 subdivisions: nasopharynx, oropharynx, and laryngopharynx
Lower respiratory structures and functions
Trachea
Cylindrical tube that extends downward anterior to the
esophagus and into the thoracic cavity
Splits into right and left primary bronchi
Inner wall is lined with ciliated mucous membrane with many
goblet cells
Goblet cells product mucus, that traps incoming particles
Wall is supported by 20 incomplete (C-shaped) cartilaginous
rings that keep the airway open
Bronchial Tree
Consists of branched, mucous membrane-lined tubular airways, leading from the trachea to the microscopic air sacs of thelungs, called alveoli
Primary bronchi
first branches of the bronchial tree; branch
directly off the trachea; each leads to a lung
Secondary Bronchi
branches of the main bronchi; each enters
a lobe of a lung
Tertiary Bronchi
branches of the lobar bronchi; each enters a
segment of a lung
Bronchioles
Bronchioles: smaller tubular organs that branch off the
segmental bronchi
Terminal Bronchioles
branches off larger bronchioles; smallest
bronchioles that conduct air, without performing gas exchange
Respiratory Bronchioles
branch off terminal bronchioles; contain
alveoli, so can perform gas exchange
Alveolar Ducts
branch off respiratory bronchioles
Alveolar Sacs
branch off alveolar ducts; consist of air sacs called
alveoli
Alveoli
consist of simple squamous epithelium, which conducts rapid gas exchange between the air and blood with the associated capillaries; closely surrounded by extensive capillary networks
Larynx
An enlargement in the airway superior to the trachea and
inferior to the laryngopharynx
Transports air in and out of the trachea
Helps keep particles from entering the trachea
Houses the vocal cords
Composed of a framework of muscles and cartilage bound by
elastic tissue
Larger cartilages of the larynx
Thyroid cartilage (Adam’s apple)
Lungs
Soft, spongy, cone-shaped organs of the respiratory system
Separated medially by the mediastinum, and enclosed by the
diaphragm and thoracic cage
Occupy most of thoracic cavity
A primary bronchus and large blood vessels enter each lung on the medial surface
Layers of the pleurae
Visceral Pleurae
inner layer; attached to the surface of each lung
Parietal Pleurae
outer layer; lines the thoracic cavity
Compare and contrast the mechanism of inspiration and expiration
Inspiration
Diaphragm and the external intercostal muscles
Muscles that expand the thoracic cavity for normal inspiration
Diaphragm contracts and moves downward, enlarging the
thoracic cavity
External intercostals contract to move ribs and sternum upward
and outward
Muscle contraction results in pressure in lungs falling to 2 mm below atmospheric pressure; this causes air to rush into the lungs
Maximal inspiration (a deep breath): requires contraction of several other muscles (pectoralis minor, sternocleidomastoid, scalenes), to enlarge the thoracic cavity even more
Due to surface tension between the 2 layers of the pleura, as
the thoracic cavity expands, the lungs expand with it
Expiration
Results from the passive process of elastic recoil of the muscles and lung
tissues, and from the surface tension within the alveoli
The diaphragm and external intercostal muscles relax and the lungs recoil,
decreasing the volume of the thoracic cavity
As the diaphragm recoils, abdominal organs spring back to original shape,
which pushes the diaphragm upward
As the lungs recoil, the pleura and chest wall are pulled inward
Volume and Pressure relationships in thoracic cavity
Pressure: Pressure is the tipping point for volume as it brings in air or forces it out. Pressure goes from high to low. So enviromental pressure is forced into the lungs when the lungs pressure is low as the environmental pressure is usually higher. The muscles and diaphragm are used in order to push the air out (expiration)
Volume: The volume allowed into the thoracic cavity is affected by the pressure from the environment as well as internal pressure. When the internal pressure is lower the environmental pressure pushes air into the lungs, therefor making the volume increase with the current air flow
Respiratory volumes and capacities
Maximal inspiration (a deep breath): requires contraction of several other muscles (pectoralis minor, sternocleidomastoid, scalenes), to enlarge the thoracic cavity even more
Tidal volume (TV): volume of air that enters or leaves the lungs during one respiratory cycle; average is ~500 mL
Inspiratory reserve volume (IRV): volume of air that can be inhaled in addition to the tidal volume, during forced inspiration; average is ~3,000 mL
Expiratory reserve volume (ERV): volume of air that can be exhaled during a
maximal forced expiration, beyond the tidal volume; average is ~1,200 mL
Residual volume (RV): volume of air that remains in the lungs after a maximal expiration; average is ~1,200 mL; cannot be measured with a spirometer
Inspiratory capacity (IC) is volume of air that can be inhaled after a
normal, resting expiration; IRV + TV (~3,500ml)
Functional residual capacity (FRC) is volume of air that remains in
lungs after a resting expiration; ERV + RV (~2,300 mL)
Vital capacity (VC) is maximum volume of air that can be exhaled
after a maximal inspiration; TV + IRV + ERV (~4,600ml)
Total lung capacity (TLC) is total volume of air the lungs can hold; VC
RV (~5,800 mL); varies with age, gender, body size
Internal vs. external respiration
External respiration, the gas exchange between lungs and blood
Internal respiration: gas exchange between the blood and body cells
Disorders of the respiratory system
Pneumonia
Bacterial or viral infection of the lungs. Bacterial infection, viral infection or aspiration are causes and risk factors. Fever, shortness of breath and chills are the symptoms. Over counter medications, antibiotics and oxygen therapy are the treatment options.
Lung Cancer
Uncontrolled cell growth & development of tumor in lungs. Smoking (90% of cases), second-hand smoke and asbestos exposure are causes and risk factors. Occurs at later stages, chest pain and shortness of breath are symptoms. Radiation, chemo therapy and surgical removal are the treatment options
Tuberculosis
Bacterial infection in the respiratory system caused by mycobacterium tuberculosis. Contagious inhaled, weakened immune system and drug/alcohol abuse are causes and risk factors. Latent 13 asymptomatic, cough with thick mucus, weight loss, night sweat are the symptoms. Long term antibiotics, surgery and medication are the treatment options
Seasonal Flu
A viral infection, there are many variations of this virus and it changes rapidly, year to year which changes in severity and symptoms. Inhaled respiratory droplets, age and occupation are causes and risk factors. Dry cough, fatigue and congestion are the symptoms. Early vaccination, over the counter meds and antiviral medications.
COPD
Chronic obstructive pulmonary disorder chronic bronchitis, emphysema & asthma. Asthmatic bronchitis, tobacco smoke and dust are causes and risk factors. Chronic cough, shortness of breath and wheezing are the symptoms and Smoking lessation, medications and bronchodilations are treatment options