Functions zGas exchange between air and circulating blood zMovement of air into and out of the body zProtection of respiratory surfaces and defense against pathogens zProducing sounds

Respiratory mucosa zLines the respiratory tract zHelps to filter debris and microoganisms zNasal mucosa- prepares the air you breathe by warming and humidifying it

Pharynx zChamber shared by the digestive and respiratory tracts

Larynx zCovered my the epiglottis zCartilaginous structure surrounding an opening, ‘the glottis” zAir passing through the glottis vibrates the vocal folds producing sound waves zChildren have short vocal fold- higher pitched, at puberty the larynx of males enlarges more than females, resulting in lower pitched voices

Trachea “windpipe” zFlexible tube surrounded by thin C shaped pieces of cartilage zBranches to form the left and right bronchus

The lungs zRight and left lung in the pleural cavities zBase of the lungs rest on the diaphragm zRight 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

Bronchi zExtrapulmonary bronchi prior to entry into the lungs zIntrapulmonary bronchi after entry into the lungs zPrimary bronchi divide into secondary bronchi and there is one for each lobe, R.side has 3 and L. side has 2 zFurther divide into tertiary bronchi which supply air to a single bronchopulmonary segment, the cartilage surrounding bronchi lessen with each division

Bronchioles zFurther division of tertiary bronchi create bronchioles zOne tertiary bronchus supplies air to about 6500 bronchioles zMade of a lot of smooth muscle and no cartilage, they control the airflow to the lungs

Alveolus (air sacs) zEach lung contains 150 million alveoli zCapillaries surround each alveolus zElastic tissue also surround them to help with exhalation

Respiratory Physiology zExternal respiration- exchange of oxygen and carbon dioxide between the body’s interstitial fluids and the external environment yPulmonary ventilation- breathing yGas diffusion yTransportation of oxygen and carbon dioxide zInternal respiration- absorption of oxygen and release of carbon dioxide by cells

Pulmonary Ventilation zPhysical movement of air into and out of the respiratory tract zMaintains adequate alveolar ventilation- movement of air into and out of the alveoli

Pressure and air flow to the lungs zAt the start of a breath, P inside and outside the thoracic cavity are equal zDiaphragm contracts and thoracic cavity size increases, and P. decreases. This P. difference cause atm. P. to push air into the body zDiaphragm relaxes, size of cavity decrease and P. increases, P. inside is greater than outside so air is forced out.

Inhalation and Exhalation zDirection of airflow is determined by the relationship between atmospheric pressure and intrapulmonary pressure zRespiratory cycle- one inhalation and one exhalation zM. of Inhal- Diaphragm and external intercostals zM. of Exhal- Internal intercostals, abdominal muscles

Alveolar Ventilation zAmount of air reaching alveoli each minute (approx. 4.2 liters/minute) zAir in alveoli contains more CO2 than atm. Air because the air being exhaled mixes w air being inhaled