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level: respiratory system

Questions and Answers List

level questions: respiratory system

Question	Answer
- air enters and leaves the body through the nose - air is cleaned, filtered, warmed and moistened before entering the body - nasal secretions also contain an enzyme (lysozyme) which can kill foreign microorganisms	nasal cavity
- have a mucous lining - epithelial lining contains goblet cells which secrete a clear stick mucus - mucus traps dirt particles and microbes before entering the lungs - epithelial cells contain cilia which are microscopic hair-like structures that beat back and forth - cilia helps move mucus along and trap the particles, also sweeps dirty mucus up the trachea and into the throat	nasal cavity and upper airways
- epiglottis: flaps of tissue which, when swallowing, close off the trachea to prevent food and liquid from entering the lungs - larynx: a passage way for air and organ of voice, air going to and from the lungs passes through the larynx, contains vocal cords which vibrate to make sound	upper airways
- all passage ways for air - trachea and bronchi have a smooth muscle later but they are further reinforced with C-shaped rings of cartilage - prevent the tubes from collapsing during inhalation - bronchioles have smooth muscles without cartilage - bronchioles terminate in microscopic clusters of air sacs called alveoli	trachea, bronchi and bronchioles
- takes up most of the lung - gas exchange takes place at the alveoli - well supplied with blood capillaries increasing efficiency of gas exchange	alveoli
- double layered: visceral and parietal pleural membranes - between the layers is a pleural cavity containing pleural fluid - membranes lubricate the surfaces: allows the layers to slide easily over each other - help keep lungs in position	pleural membrane
- muscles are involved in contracting and relaxing during inspiration and expiration to change the volume of thoratic cavity and therefore changes the volume of the lungs	diaphragm and intercostal muscles
- a primary role of the respiratory system - concentration gradients are required for gas exchange to occur - when air is breathed in, it is high in oxygen concentration - the blood in the capillaries around the alveoli has a low oxygen concentration - oxygen will make more via diffusion from high to low concentration - oxygen dissolves in the moisture on the inside of the alveolus and diffuses through the membrane, through the walls of the capillaries and into the blood - the blood in capillaries around the alveoli are high in carbon dioxide - carbon dioxide diffuses out of the blood and into the air in the alveolus	gas exchange and concentration gradient
- have a very large internal surface area due to many alveoli: more surface are for gas exchange - alveolis are supplied with close blood vessels/capillaries - concentration gradients are maintained: blood is continuously moved through blood vessels , air is continuously moved in and out of lungs - alveolis are one cell thick: decrease distance for easier diffusion - thin layer of moisture in alveoli for easier gas diffusion - lungs are deep in the body to prevent excess evaportaion	lungs and alveoli
- the process of moving air into and out of the lungs - the exchange of oxygen and carbon dioxide between lungs and air	breathing
- transport of oxygen from the air to tissues/cells and carbon dioxide in the opposite direction	respiration
- thoracic: the space the lungs occupy - volume and pressure changes are important in allowing ventilation to occur - increase thoracic volume decreases the pressure in lungs	thoracic volume
- the pressure of air in the lungs is less than outside - low pressure inside is achieved by increasing the volume of lungs - the diaphragm and intercostal muscles contract - the diaphragm moves down - the rib cage moves out and up - air flows in until pressure is equal - rib cage becomes important in heavier breathing	inspiration
- pressure of air in the lungs is greater than outside - high pressure inside is achieved by decreasing the volume of lungs - diaphragm and intercostal muscles relax - diaphragm moves up - rib cage move down and in - lung volume decreases and air is greater inside, air flows out until pressure is equal - passive process	expiration
- internal: the exchange of oxygen and carbon dioxide between the blood and the tissues that need it - external: the movement of oxygen and carbon dioxide between the lungs and the bloodstream	internal and external respiration
- oxygen enters the body and is delivered via blood to cells - carbon dioxide is removed from cells, delivered to the lungs via blood and is excreted	systems
- causes mucus lining to produce excess mucus - can destroy/slow the action of cilia: unable to clear mucus - congestion in airways: become prone to secondary infections - alveoli are destroyed: loss of gas exchange surface area - contains carcinogenic increasing the risk of lung cancer	smoking