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Respiratory System Emely Casillas Period 1 - Coggle Diagram
Respiratory System Emely Casillas Period 1
Major functions of the respiratory system
Oxygen is required by cells to break down nutrients, to release energy and produce ATP; carbon dioxide is a product of nutrient breakdown, which has to be excreted from the body
Respiration: process of gas exchange between the atmosphere and cells
.
Removes waste gases, including carbon dioxide, from the body when you exhale
Upper respiratory structures and functions
Nose
Nostrils provide openings for entrance and exit of air
Supported by bone and cartilage
Nostrils contain coarse hairs, which prevent entry of particles
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
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
pharynx
Space behind oral and nasal cavities and larynx
Common passageway for air and food from nasal & oral cavities
3 subdivisions: nasopharynx, oropharynx, and laryngopharynx
Lower respiratory structures and functions
Larynx
An enlargement in the airway superior to the trachea and
inferior to the laryngopharynx
Houses the vocal cords
Composed of a framework of muscles and cartilage bound by
elastic tissue
trachea
Cylindrical tube that extends downward anterior to the
esophagus and into the thoracic cavity
Inner wall is lined with ciliated mucous membrane with many
goblet cells
Wall is supported by 20 incomplete (C-shaped) cartilaginous
rings that keep the airway open
bronchial tree
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: 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
lungs
Soft, spongy, cone-shaped organs of the respiratory system
Separated medially by the mediastinum, and enclosed by the
diaphragm and thoracic cage
A primary bronchus and large blood vessels enter each lung on the medial surface
Volume and Pressure relationships in thoracic cavity
Increasing the volume of the thoracic cavity causes air pressure inside the lungs to decrease (an inverse relationship)
Muscles that expand the thoracic cavity for normal inspiration
Diaphragm contracts and moves downward, enlarging the
thoracic cavity
Due to surface tension between the 2 layers of the pleura, as the thoracic cavity expands, the lungs expand with it
The diaphragm and external intercostal muscles relax and the lungs recoil, decreasing the volume of the thoracic cavity
Respiratory volumes and capacities
Spirometry: study of various air volumes that move into and out of the lungs due to different degrees of effort
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
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
Internal respiration: gas exchange between the blood and body cells
External respiration, the gas exchange between lungs and blood
Disorders of the respiratory system
COPD:Chronic obstructive pulmonary disease, or COPD, refers to a group of diseases that cause airflow blockage and breathing-related problems. It includes emphysema and chronic bronchitis
Tuberculosis (TB) is a disease caused by germs that are spread from person to person through the air
Pneumonia is an infection of the lungs that can cause mild to severe illness in people of all ages
Lung cancer begins in the lungs and may spread to lymph nodes or other organs in the body, such as the brain. Cancer from other organs also may spread to the lungs
Seasonal influenza is characterized by a sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose
Layers of the pleurae
Serous fluid lubricates the pleural cavity between the 2 layers
Parietal pleura: outer layer; lines the thoracic cavity
Visceral pleura: inner layer; attached to the surface of each lung
Compare and contrast the mechanism of inspiration and expiration
Ventilation (breathing): movement of air from outside the body into the bronchial tree and alveoli, and back out
Inspiration: Air moves from higher to lower pressure
Atmospheric pressure: pressure exerted by the air on all
objects in contact with it; force that moves air 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
As the lungs expand in size, a lipoprotein mixture called
surfactant keeps the alveoli inflated, preventing collapse
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
Increased surface tension in the alveoli decreases their volume, Intra-alveolar pressure increases to about 1 mm Hg above atmospheric pressure, As a result, air rushes out of the lungs into the atmosphere