Chapter 8 - The Respiratory System Flashcards
What is the function of the respiratory system?
To bring oxygen into the body to be used by cells and to remove carbon dioxide from the body.
What are the organs of the respiratory system?
- nose
- trachea
- bronchi
- lungs
What is the process of inspiration?
- for air to flow into the lungs, the air pressure inside the lungs must be less than that of surrounding atmosphere.
- this is achieved by the contraction of the diaphragm and external intercostal muscles which increases the volume of the chest cavity as the diaphragm becomes flatter and the rib cage moves upwards.
- air flows in the nose and trachea until the pressures are equal
What is the process of expiration?
- opposite way to inspiration.
- the diaphragm and intercostal muscles relax, so the diaphragm bulges and the rib cage moves down which decreases the volume of the lungs
- air pressure is now greater than outside of the body and air flows out through the trachea and nose until the pressures are equal
Why is the structure of the lungs suitable for gas exchange?
- alveoli gives a huge internal surface area, large amounts of gases can be exchanged
- lung volume can be changed by movement of the respiratory muscles, so that air is made to flow in and out of the lungs
- each alveolus is well supplied with blood vessels, so that as much blood as possible is close to the air in the alveolus
- the membrane that forms the wall of the alveolus is very thin so that gas molecules do not have far to travel when moving in or out of blood
- lungs are positioned deep inside the nosy to prevent excessive evaporation of the fluid that covers the respiratory surfaces
What is the function of the pharynx?
Allows air from to nasal cavity to pass through.
What is the function of the larynx?
- the organ of the voice
- air passes through the larynx going to and from the lungs
- contains vocal chords which can vibrate to create sound
What is the function of the trachea?
- carries air to and from the lungs
- is lined with a mucous membrane and cells with cilia. The cilia beat to move mucus and trapped particles upward.
What is the function of the intercostal muscles?
- muscles between the ribs
- move the rib cage upwards and outwards to increase volume of the chest cavity and lungs when breathing in
What is the function of the diaphragm?
- contracts and flattens down, increasing the volume of the chest cavity and kings when breathing in.
What is the function of the alveoli?
- tiny air sacs that make up most of the lungs
- occur in clusters and have very thing walls that are well supplied with blood capillaries for the exchange of oxygen and carbon dioxide
What is the function of the bronchioles?
- very fine tubes with walls of smooth muscle
- the finest of them end with alveoli
What is the function of the bronchi?
- two primary bronchi branch from the trachea
What is the function of the epiglottis?
- flap of tissue that closes the trachea so that food and liquid cannot enter the lungs
What is the process of gas exchange?
- the artery to the lungs brings deoxygenated blood to the capillaries
- carbon dioxide diffuses from the higher concentration in the blood to the lower concentration in the alveolus
- oxygen diffuses from the high concentration in the alveolus to the blood
- oxygenated blood leaves the capillaries and is taken to the heart in the veins from the lungs
