respiratory system Flashcards
what is the function of the nasal cavity?
- moisten and warm air
- cleans air
- smell receptors
what is the function of the pharynx?
- air from the nasal cavity passes through
what is the function of the epiglottis?
- flap of tissue
- closes during swallowing to the trachea so food cannot enter the lungs
what is the function of the larynx?
- contains vocal cords
- enables sound productions
what is the function of the trachea?
- lined with cilia + mucus-secreting cells
- provides path for air
what is the function of the bronchi?
- c shaped rings of catilage
- takes air to lungs
what is the function of the bronchioles?
- fine tubes
- smooth muscle
- carry air to alveoli
what is the function of the alveoli?
- tiny air sacs
- thin walls
- sit of gaseous exchange
what is the function of the intercostal muscles?
- between the ribs
- move the rib cage
what is the function of the diaphragm?
- contracts and flatterns
what is the function of the lungs?
- occupy all chest cavity
- covered by a pleural membrane
- move air
- site for gaseous exchange
what occurs during inhalation/inspiration?
- intercostal muscles contract
- ribs and sternum move up and out
- diaphragm contracts
- increase volume of thoratic cavity
- air pressure decreases
- air rushes to lungs = pressure (H>L)
what happens during expiration/exhalation?
- intercostal muscles relax
- ribs and sternum move down and in
- diaphragm relaxes
- decrease volume of thoratic cavity
- air pressure increases
- air forced out of lungs = pressure (H>L)
what is the alveoli?
- tiny air sacs
- resemble a bunch of grapes
- very thin walls
- surrounded by cpillaries
what is gas exchange?
- exchange of O2 and CO2 between alveoli and capillary
- passive diffusion (H>L)
what is gas exchange?
- exchange of O2 and CO2 between alveoli and capillary
- passive diffusion (H>L)
how are lungs efficient for gas exchange?
LARGE SA OF ALVEOLI
= large amounts of gases can be exchanged in a short time
ALVEOLUS WELL SUPPLIED WITH BLOOD
= as much blood as possible is close to alveolus > more blood can have gasses exchanged
BLOOD FLOW CONTINUOUSLY TO ALVEOLUS
= difference in concentration gradient > continuous diffusion
MEMBRANE THICKNESS
= 1 cell thick > rapid diffusion
what is the process of gaseous exchange?
- blood in capillaries surrounding the alveoli is brought to the lungs by the pulmonary artery
- blood has low oxygen
- oxygen dissolves in moisture on inside of the alveolus and diffuses through the membrane, the walls of the capillaries, and into the blood
- blood that arrives at capillaries of alveoli has come from body circulation where it picked up CO2
- conc of CO2 in alveolar capillaries in high compared to conc of air in elveolus
- CO2 diffuses out of blood and into alveolus
what is the cause of emphysema?
- long term exposure to irritating particles
- shortness of breathe
- affects smokers > irritants in tobacco
what is the effect of lung cancer on gas exchange?
excessive mucas secretion > particles irritate muscous membranes
what is the effect of emphysema on gas exchange?
- alveoli loses elasticity
- inadequate SA for efficient gas exchange
- difficult ventilating lungs
what is the effect of pheumonia on gas exchange?
- inflation = secretion of fluid + mucus = reduceing amount of air they contain
- difficulty breathing
what is the effect of tuberculosis on gas exchange?
- inadequate SA for gas exchange
- destroyed tissue is replaced with inelastic fiborous tissue
what is the effect of asthma on gas exchange?
- muscles surrounding bronchioles spasm = narrows airway
- irritation of membranes lining airway causes excess secretion
what is lung cancer and the cause?
- development of a tumour in lung
- smokers
what is pheumonia and the cause?
- infection of lungs
- caused by bacteria, fingi and other organisms
what is tuberculosis and the cause?
- infection caused by bacterium
- bacteria destroys lung tissue
what is asthma and the cause?
- allergic response to foreign substance that enter the body
