Respiratory System Chapter 10

Function of respiratory system

Respiration is more than simply breathing... it’s a 4 step process breathing external respiration internal respiration cellular respiration

Structures of human respiratory system nasal cavity pharynx larynx trachea bronchi bronchioles alveoli associated bones & muscles (which ones?)

Human respiratory system

System zones conducting zone respiratory zone

The alveoli

Ventilation

What causes inhalation?

Ventilation both inspiration & expiration can be modified

Lung volumes & capacities

Lung capacities as diagnostic tool

Regulation of breathing Breathing is regulated by 2 neural pathways – central chemoreceptors – peripheral chemoreceptors – both types modify rate & depth of breathing

Effects of P CO2 & pH on ventilation

Negative feedback to maintain proper CO 2 levels

Effects of P O2 on ventilation

O 2 transport in the blood

Loading & unloading of Hb loading unloading

CO 2 transport in the blood Carried in 3 forms in the blood – dissolved CO 2 – as carbaminohemoglobin – as bicarbonate ion (HCO 3 - )

Acid-base balance of blood average pH of blood is 7.4 fall in pH below 7.35 rise in pH above 7.45

Malfunctioning respiratory system Asthma – constriction of airways due to muscle contraction or inflammation – reversible – caused by genetic & environmental factors – symptoms: coughing, wheezing, SOB, tight chest – tx: inhalers with smooth muscle relaxers &/or anti- inflammatories chronic obstructive pulmonary disease (COPD) – lung disease with persistent poor airflow due to breakdown of lung tissue – non-reversible – caused primarily by smoking – symptoms: persistent cough, SOB, sputum production – tx: stop smoking, bronchodilators, O 2 therapy, lung transplant