The respiratory system

Alveoli and alveolar ducts

adenoids   

(ad'in-oidz)
collection of lymphatic tissue at the rear of the nose.

alveolar duct   

(al-vee-oh'lar)
small passages connecting the respiratory bronchioles and alveolar sacs.

alveoli   

(al-vee-oh'lee)
very small air sacs in the lungs through which oxygen and carbon dioxide are exchanged.

bronchi   

(brong�kee)
main branch passageways extending from the distal trachea: singular: bronchus.

bronchial tubes   

(brong�kee-al)
main branch passageways extending from the distal trachea.

bronchiole   

(brong'kee-ole)
the finest divisions of the branched bronchial tree.

carbon dioxide   

(often said as: see-oh-two)
odourless, colourless gas produced in tissue cells as a by-product of metabolism; CO₂ is excreted by the lungs.

carina   

(ka-ree'nah)
lowest part of the tracheal cartilage which forms a ridge between the openings of the right and left principal bronchi .

diaphragm   

(dy�ah-fram)
the musculomembranous 'partition' between the chest cavity and abdominal cavity which acts as a bellows in breathing.

diffusion   

(di-fyoo�zhun)
the movement of molecules of a liquid or gas from a higher to a lower concentration.

exhale   

(eks-hale�)
to expel deoxygenated air from the lungs by breathing.

heart space   

space between the right and left lungs to accommodate the heart.

larynx   

(lar�inks)
the organ of voice.

lung   

major organ of respiration; consists of spongy, porous, elastic tissue.

medulla oblongata   

(me-dul�lah ob-lon-gar�tar)
an area of the brain which shares concern for respiratory function with the pons.

mucous membrane   

(myoo�kus)
thin layer of smooth tissue which lines many cavities and has special ability to secrete a slimy fluid called mucous.

nasopharynx   

(nay-zo-fa�rinks)
upper part of the back of the throat where the nasal cavity opens into the pharynx .

nose   

organ of the sense of smell situated on the face between the eyes and mouth.

olfactory receptors   

(ol-fak�tor-ee)
nerves in the upper part of the nasal cavity concerned with the sense of smell.

oxygen   

(ok�si-jen)
colourless, odourless gas essential to the life of human tissue cells.

pharynx   

(fa�rinks)
area in the back of the mouth which serves as passageway for air from the nasal cavity to the larynx and for food from the mouth to the oesphagus.

pleura   

(ploor�ah)
membranous sac which encloses the lungs and lines the chest cavity; parietal pleura lines the chest cavity and visceral pleura adheres closely to the lungs.

pleural cavity   

(ploor�al)
the space between the parietal and visceral pleura.

pons (Varolii)   

(ponz (va-roh'lee-eye))
an area of the brain which shares concern for respiratory function with the medulla oblongata; often just referred to as the pons.

respiratory system   

(re-spi�rah-tor-ee)
the organs and structures which provide the route by which oxygen gains entry to the body and the route by which carbon dioxide is excreted.

thorax   

(thor'aks)
the chest cavity; adjective: thoracic.

trachea   

(trak�ee-ah)
passageway for air between the larynx and the bronchi.

vocal cords   

(voh�kul)
folds of mucous membrane which vibrate to produce voice.