Chapter 19 Respiratory System ventilation external respiration transport internal respiration cellular respiration Respiration- Consists of the following events: 19-2

Organs of the Respiratory System 19-3 Gas exchange.mov

Upper Respiratory Tract 19-4

Mucous in Respiratory Tract 19-5

Sinuses Air-filled spaces in maxillary, frontal, ethmoid, and sphenoid bones 19-6

Larynx 19-7

Vocal Cords 19-8

Trachea Cross section of trachea Wall of trachea 19-9

Tracheostomy Performed to allow air to bypass an obstruction within the larynx 19-10

Bronchial Tree 19-11

Alveoli Gas exchange.mov

Diffusion Across Respiratory Membrane 19-13

Location of Lungs 19-14

Transverse Section of Lungs 19-15

Lungs at Rest When lungs are at rest, the pressure on the inside of the lungs is equal to the pressure on the outside of the thorax 19-16

Inspiration Intra-alveolar pressure decreases to about 758mm Hg as the thoracic cavity enlarges 19-18

Expiration 19-20

Respiratory Volumes tidal volume – inspiratory reserve volume – expiratory reserve volume – residual volume – Breathing.mov

Respiratory Capacities inspiratory capacity = TV + IRV functional residual capacity = ERV + RV vital capacity = TV + IRV + ERV total lung capacity = VC + RV 19-23

Respiratory Volumes and Capacities 19-24

Nonrespiratory Air Movements coughing sneezing laughing crying hiccuping yawning speech 19-26

Factors Affecting Breathing Decreased blood oxygen concentration stimulates peripheral chemoreceptors in the carotid and aortic bodies 19-29

Alveolar Pores allow air to pass from one alveolus to another 19-32

Respiratory Membrane consists of the walls of the alveolus and the capillary 19-33

Diffusion Through Respiratory Membrane 19-34

Oxygen Transport Most oxygen binds to to form oxyhemoglobin Oxyhemoglobin releases oxygen in the regions of body cells Much oxygen is still bound to hemoglobin in the venous blood 19-35

Carbon Dioxide Transport dissolved in plasma combined with hemoglobin in the form of bicarbonate ions 19-37

Life-Span Changes reflect accumulation of environmental influences reflect the effects of aging in other organ systems cilia less active mucous thickens swallowing, gagging, and coughing reflexes slow macrophages in lungs lose efficiency increased susceptibility to respiratory infections “barrel chest” may develop bronchial walls thin and collapse dead space increases 19-40

Clinical Application The Effects of Cigarette Smoking on the Respiratory System cilia disappear excess mucus produced lung congestion increases lung infections lining of bronchioles thicken bronchioles lose elasticity emphysema fifteen times more common lung cancer more common much damage repaired when smoking stops Asthma.mov Smocking.mov