Chapter 28 Respiration. I. Introduction A. Functions of the respiratory system 1. Works in conjunction with the circulatory system 2. Provides oxygen.

Chapter 28Chapter 28

Respiration Respiration

I. IntroductionI. Introduction

A. Functions of the respiratory A. Functions of the respiratory systemsystem1. Works in conjunction with 1. Works in conjunction with

the circulatory systemthe circulatory system2. Provides oxygen for cellular 2. Provides oxygen for cellular

respirationrespiration

B. The respiratory system and B. The respiratory system and smokingsmoking

II. Evolution of the respiratory II. Evolution of the respiratory systemsystem

A. Gas exchange in all A. Gas exchange in all organisms depends on organisms depends on diffusiondiffusion1. The respiratory surface must 1. The respiratory surface must

remain moistremain moist2. The respiratory system must 2. The respiratory system must

have a large surface areahave a large surface area

II. Evolution of the respiratory II. Evolution of the respiratory systemsystem

B. Changes in the respiratory B. Changes in the respiratory system needed to system needed to accommodate organismsaccommodate organisms1. Increase in surface area of 1. Increase in surface area of

the organisms over timethe organisms over time2. Conversion from aquatic to 2. Conversion from aquatic to

terrestrial environmentsterrestrial environments

III. Respiratory systems and gas III. Respiratory systems and gas exchangeexchange

A. Interrelated with circulatory A. Interrelated with circulatory systemsystem

B. Mechanisms of gas B. Mechanisms of gas movementmovement1. Bulk flow from areas of 1. Bulk flow from areas of

higher pressure to areas of higher pressure to areas of lower pressurelower pressure

2. Simple diffusion at the tissue 2. Simple diffusion at the tissue or lung levelor lung level

III. Respiratory systems and gas III. Respiratory systems and gas exchangeexchange

C. Gas exchange in aquatic C. Gas exchange in aquatic environments—gillsenvironments—gills

D. Gas exchange in terrestrial D. Gas exchange in terrestrial environmentsenvironments1. Book lungs1. Book lungs2. Tracheae2. Tracheae3. Lungs3. Lungs

IV. Human respiratory systemIV. Human respiratory system

A. The conducting portionA. The conducting portion1. Carries air to the lungs1. Carries air to the lungs2. Warms and moistens air 2. Warms and moistens air

moving through itmoving through it3. Cilia that line the trachea, 3. Cilia that line the trachea,

bronchi, and bronchioles bronchi, and bronchioles filter dust particlesfilter dust particles

IV. Human respiratory systemIV. Human respiratory system

B. Gas exchange portionB. Gas exchange portion 1. The alveoli have an 1. The alveoli have an

enormous surface areaenormous surface area2. Capillaries surround the alveoli2. Capillaries surround the alveoli3. The mechanism of gas exchange 3. The mechanism of gas exchange

and transportand transporta. Oxygen and a. Oxygen and

hemoglobinhemoglobinb. Carbon dioxide and b. Carbon dioxide and

bicarbonate ionsbicarbonate ions

IV. Human respiratory systemIV. Human respiratory system

C. Mechanics of breathingC. Mechanics of breathing1. Inspiration—active inhalation of 1. Inspiration—active inhalation of

air air a. Diaphragm and rib a. Diaphragm and rib

muscles contract, muscles contract, making the chest making the chest cavity largercavity larger

b. Chest expansion b. Chest expansion causes the lungs to causes the lungs to expand; vacuum expand; vacuum draws in airdraws in air

IV. Human respiratory systemIV. Human respiratory system

C. Mechanics of breathing C. Mechanics of breathing (cont.)(cont.)2. Expiration—passive 2. Expiration—passive

exhalation of air when exhalation of air when muscles are relaxedmuscles are relaxed

IV. Human respiratory systemIV. Human respiratory system

D. Control of respirationD. Control of respiration1. Description of breathing1. Description of breathing2. Regulation of breathing by 2. Regulation of breathing by

carbon dioxidecarbon dioxide