FunctionsGas exchange between air and circulating

bloodMovement of air into and out of the bodyProtection of respiratory surfaces and

defense against pathogensProducing sounds

Respiratory mucosaLines the respiratory tractHelps to filter debris and microoganismsNasal mucosa- prepares the air you

breathe by warming and humidifying it

PharynxChamber shared by the digestive and

respiratory tracts

LarynxCovered my the epiglottisCartilaginous structure surrounding an

opening, ‘the glottis”Air passing through the glottis vibrates the

vocal folds producing sound wavesChildren have short vocal fold- higher

pitched, at puberty the larynx of males enlarges more than females, resulting in lower pitched voices

Trachea “windpipe”Flexible tube surrounded by thin C shaped

pieces of cartilageBranches to form the left and right

bronchus

The lungsRight and left lung in the pleural cavitiesBase of the lungs rest on the diaphragmRight lungs has 3 lobes, and left has only

2 lobes. Right lung is slightly larger, due to heart lying a little more on the left side

BronchiExtrapulmonary bronchi prior to entry into the

lungsIntrapulmonary bronchi after entry into the lungsPrimary bronchi divide into secondary bronchi

and there is one for each lobe, R.side has 3 and L. side has 2

Further divide into tertiary bronchi which supply air to a single bronchopulmonary segment, the cartilage surrounding bronchi lessen with each division

BronchiolesFurther division of tertiary bronchi create

bronchiolesOne tertiary bronchus supplies air to about

6500 bronchiolesMade of a lot of smooth muscle and no

cartilage, they control the airflow to the lungs

Alveolus (air sacs)Each lung contains 150 million alveoliCapillaries surround each alveolusElastic tissue also surround them to help

with exhalation

Respiratory PhysiologyExternal respiration- exchange of oxygen and

carbon dioxide between the body’s interstitial fluids and the external environment Pulmonary ventilation- breathing Gas diffusion Transportation of oxygen and carbon dioxide

Internal respiration- absorption of oxygen and release of carbon dioxide by cells

Pulmonary VentilationPhysical movement of air into and out of

the respiratory tract Maintains adequate alveolar ventilation-

movement of air into and out of the alveoli

Pressure and air flow to the lungsAt the start of a breath, P inside and outside the

thoracic cavity are equalDiaphragm contracts and thoracic cavity size

increases, and P. decreases. This P. difference cause atm. P. to push air into the body

Diaphragm relaxes, size of cavity decrease and P. increases, P. inside is greater than outside so air is forced out.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Inhalation and ExhalationDirection of airflow is determined by the

relationship between atmospheric pressure and intrapulmonary pressure

Respiratory cycle- one inhalation and one exhalation

M. of Inhal- Diaphragm and external intercostalsM. of Exhal- Internal intercostals, abdominal

muscles

Alveolar VentilationAmount of air reaching alveoli each

minute (approx. 4.2 liters/minute)Air in alveoli contains more CO2 than atm.

Air because the air being exhaled mixes w air being inhaled