chapter 8 - the respiratory system Flashcards
what are the functions of the respiratory system
- continual supply of oxygen, and continual removal of carbon dioxide
- elimination of volatile waste substances
- elimination of excess heat from the body
what is the nasal cavity
- filters (hairs/cilia), moistens (mucous) and warms (capillaries) air before entering the lungs
- contains smell receptors and acts as a resonating chamber for speech sounds
what is the pharynx
- where air from the nasal cavity passes through
what is the epiglottis
- a flap of tissue that closes off the trachea so food cannot enter the lungs when swallowing
what is the larynx
- air passes through the larynx
- contains vocal chords which vibrate to make sound
what is the trachea
- carries air to and from the lungs
- cilia beat to move mucous and trapped particles upwards to throat to be swallowed
what is the bronchi
- two primary bronchi branch from the trachea
- divide into secondary and tertiary bronchi
what is the bronchioles
- very fine tubes with walls of smooth muscle
- ends in groups of air sacs (alveoli)
what is the alveoli
- tiny / millions = increased SA = increased EOG
- very thin walls (one cell) = less distance = increased EOG
- network of capillaries = increased EOG
- film of moisture lines the alveoli = allows gas to dissolve = increased EOG
what are the ribs
- form the framework of the chest
what are the intercostal muscles
- muscles between the ribs
- move upwards and outwards to increase chest cavity
what is the diaphragm
- muscle separating chest from abdomen
- contracts and flattens downwards to increase chest cavity volume
what is the structure of the lungs
- covered by a pleural membrane, that also lines the inside of the chest
- pleural fluid between he two holds the lungs against the inside of the chest
function of the lungs
- to enable the blood to take up oxygen from he air, and carbon dioxide to pass from the blood to the air in lungs
why are the lungs well adapted to their function (gas exchange)
- large surface area: large amounts of gas can be exchanged in a short amount of time
- little travel distance: alveoli have a very thin membrane
- positioned deep in body: prevents excessive exasperation of the pleural fluid and the gases during gas exchange
- lung volume: can be changed by movements of respiratory muscles, air is continually flowing in and out of the lungs
what are the mechanics of breathing
- the process by which air is moved into and out of the lungs (ventilation)
what is air pressure
- air flows from places of a higher pressure to that of a lower pressure
- air flows due to the difference in air pressure
describe the process of inspiration
- intercostal muscles contract (extending rib age upwards and outwards), pulls on pleural membrane
- diaphragm contracts (extending chest cavity downwards)
- lung volume increases and pressure in alveoli is reduced
- air flows from area of higher pressure to lower pressure in the lungs
describe the process of expiration
- intercostal muscles contract, extending rib cage downwards and inwards
- diaphragm relaxes, pushing up into the chest cavity
- lungs recoil and lung volume decreases, increasing pressure in the lungs
- air flows from higher pressure in lungs to lower pressure outside the body
what is the respiratory system
made up of those organs which are concerned with the exchange of gases between the organism and the environment
