Respiratory System

Respiratory System – gas exchange  

Path of the Respiratory

System: 

Air enters the mouth or nose

Air continues down the pharynx past the larynx (voice box) and into the

trachea (windpipe)

The lower end of the trachea splits

into 2 bronchi

The bronchi split off into several bronchioles

 At the end of each

bronchiole there is an air sac

 

 The air sac is made

up of several alveoli

 The alveoli have

capillaries wrapped around them

Capillaries

Alveoli

Trachea

Bronchioles

Blood cells with Oxygen

Oxygen in CO2 out

Blood cells with CO2

Why would the alveoli have capillaries around them? 

This ensures that gas can pass through the walls of the capillaries

exchanging Carbon Dioxide for Oxygen The alveoli and capillaries in the lungs represent the point where the Respiratory and Circulatory

Systems interact.

When you inhale muscles in between your ribs contract and the diaphragm (a muscle below

your lungs) contracts. When you exhale the muscles in between your

ribs relax and the diaphragm relaxes.

What can make the Respiratory System not work like it should?

Asthma - respiratory disease in which certain airways in the lungs become constrictedBronchitis – mucous accumulates in the

bronchioles and does not allow as much air to pass through

Emphysema – the alveoli lose their elasticityPneumonia – the alveoli fill with liquid (pus,

mucous etc)

Facts about smokingToxic substances in tobacco (over 4,000 chemicals) bother

the lining of bronchi and destroy cilia.

Why would this be bad?

More susceptible to infections/diseases caused by air-borne particles.

Increases the risk to have cardiovascular disease – higher rate of heart attacks than a normal person

Nicotine – the main substance in a cigarette

Why is nicotine so addictive?Absorbed easily through the skin, increases levels of dopamine (feel good hormone) The problem is: dopamine wears off after a short bit and the body craves more nicotine.

Person who smokes 30 cigarettes (pack and ½) in a day gets 300 doses of nicotine a day.