human gas exchange(3.2) Flashcards
what is the trachea
airway that leads from mouth and nose to bronchi.The trachea is lined with mucus and cilia.Also has cartilage rings to ensure airways are held open
where does gas exchange take place
thorax
describe the pathway of the respiratory system
trachea , bronchi , bronchioles ,alveoli
what is the purpose of the ciliated epithelium that lines the trachea and bronchi
type of specialised cell, has projections of cilia which sweep mucus, dust and microorganisms up and away from the lungs
where can goblet cells be found
scattered throughout ciliated epithelium in the trachea
what are goblet cells
mucus producing cells that produce viscous mucus to trap dust and microorganisms to prevent them reaching the lungs
what are 3 features of the alveoli
-large surface area
-one cell thick
-surrounded by a capillary network
describe the process of inspiration(breathing in)
-external intercostal muscles contract while the internal intercostal muscles relax which pulls the ribcage up and out
-the diaphragm also contacts and flattens
-this increases the volume of the thorax so the pressure decreases
-air pressure is lower in the lungs than the atmosphere so air is drawn in.
describe the process of expiration(breathing out)
-internal intercostal muscles contract while external relax pulling ribcage in and down
-diaphragm relaxes curving upwards
-this decreases the volume in the thorax therefore increasing pressure
-air pressure is higher in the lungs than in the atmosphere so air is forced out.
how do you calculate the pulmonary ventilation rate
tidal volume X breathing rate
how can smoking affect the respiratory system
-tar can destroy the cilia which will lead to a build up of mucus
-tar can also breakdown the walls of the alveoli and cause them to merge together creating an insufficient sa for exchange
