Chapter 14 - BIO 110
Functions of the Respiratory System | Provides the body with essential ocygen and disposes of carbon dioxide |
Four processes that play a part in respiration | Breathing, external respiration, gas transport, internal respiration |
Regions of the respiratory system | Upper – nose sinuses, pharynx, epiglottis, larynx Lower – trachea, lungs, bronchi, bronchioles |
Nose | Functions – cleans incoming air, warms and moistens air, provides for the sense of smell |
Sinuses | Structure – large air filled spaces in the bones of the face, connect to nasal cavities Functions – lighten head, warm and moisten air, part of the resonating chamber that affects voice |
Pharynx | throat Structure – space behind the nose and mouth, connected to the middle ear via auditory tubes Functions – passageway for food, drink, and air, help equalize pressure |
Larynx | Also known as voice box or adam’s apple Structure – box like, made primarily of cartilage Functions – serves as a selective entrance to the lower respiratory system, source of the voice Swallowing – the larynx rises up and causes the epiglottis to cover the glottis - If this mechanism fails, food and drink may accidentally enter the trachea Voice – vocal cords vibrate and produce the voice - tension of vocal cords determines pitch |
Trachea | Windpipe Tube held open by c-shaped rings of cartilage Conducts air between environment and lungs |
Bronchial Tree | Network of progressively smaller air tubes Conduct air from trachea to each lung |
Alveoli | Minute sacs where oxygen diffuses from the inhaled air into the blood and carbon dioxide diffuses from the blood into the alveolar air to be exhaled Provide immense, internal surface area for gas exchange |
What is the mechanism of breathing | Air moves between the atmosphere and the lungs in response to pressure gradients - into lungs when pressure in atmosphere>pressure in lungs - out of lungs when pressure in lungs>pressure in atmosphere |
Inhalation | Inspiration Air moves into the lungs when the thoracic cavity increases in volume due to contraction of the diaphragm and intercostal muscles |
Exhalation | Expiration Air moves out of the lungs when the diaphragm and intercoastal muscles relax and the thoracic cavity decreases in volume |
Tidal volume | Volume of air inhaled or exhaled during a normal breath |
Inspiratory reserve volume | Volumed of air that can be inhaled in addition to a normal breath |
Expiratory reserve volume | Volume of air that can be exhaled in addition to a normal breath |
Vital capacity | Maximum volume of air that can be inhaled or exhaled in a single forced breath Tidal + inspiratory reserve + expiratory reserve |
Residual volume | Volume of air remaining in lungs after maximum exhalation |
Total lung capacity | Total volume of air in lungs after maximal inhalation Vital capacity + residual volume |
What are the three process of transport of gases between the lungs and cells | External respiration – oxygen diffuses into blood and carbon dioxide diffuses from blood Gas transport by the blood Internal respiration – oxygen diffuses out of blood and into cells, and carbon dioxide diffuses out of cells and into blood |
Basic breathing pattern | Controlled by a breathing center located in the medulla |
Carbon dioxide | Most important chemical influencing breathing rate Increased carbon dioxide prompts increased breathing rate |
Oxygen | Does not influence breathing rate unless its blood level fall dangerously low |