生理学笔记book note 3.docx

Chapter 18 Respiratory system
overview of the respiratory system
1. respiration supplies the blood with O2 and removes CO2
Five basic steps of respiration[the process of supplying the body with O2 and removing CO2]:
Ventilation(breathing): inspiration(inhalation) & expiration(exhalation)【bulk flow】
Pulmonary gas exchange: 【diffusion】
gases are changed between the alveoli(air sacs) and the blood in pulmonary capillaries.
Transport of O2 and CO2 by the blood: O2 to tissue cells and CO2 to the lungs【bulk flow】
Systemic gas exchange: 【diffusion】
gases are exchanged between blood in systemic capillaries and tissue cells of the body.
Cellular respiration: metabolic reactions to produce ATP
The respiratory system doesn’t carry out all of the steps of respiration. It’s responsible only for ventilation and gas exchange.
2. the respiratory system prised of ans
The respiratory system: nose, pharynx咽, larynx喉, trachea, primary bronchi主支气管, lungs(contain smaller bronchi, bronchioles, and numerous microscopic air sacs called alveoli)
Airways: all of the structures that carry air to and from the alveoli of the lungs.
3. the respiratory mucosa produces mucus that traps particles and lubricate the airways
The airways from the nose to the bronchioles of the lungs are lined by a mucosa(mucous membrane).
Mucociliary escalator: refers to the movement of mucus along the respiratory tract toward the pharynx. [once the mucus and trapped particles reach the pharynx, they can be swallowed or expectorated(spit out)]
The movement of cilia is paralyzed by nicotine in cigarette smoke.
Only the tips of the cilia of the respiratory mucosa actually make contact with mucus. Beneath the mucus and surrounding the remaining parts of the cilia is a thin, watery saline layer known as periciliary fluid.
Periciliary fluid facilitates movement of mucus along the respiratory tract. If the volume of periciliary fluid is reduced[cystic fibrosis], the mucus thicken and entangles the c