Respiratory Respiratory SystemSystemChapter 37-3Chapter 37-3

What is Respiration? What is Respiration?

Respiration is Respiration is notnot just breathing in oxygen just breathing in oxygen Once oxygen is pulled into the lungs, it is Once oxygen is pulled into the lungs, it is

carried to cells via the circulatory systemcarried to cells via the circulatory system Once oxygen is at the cells, it is used in Once oxygen is at the cells, it is used in

Cellular RespirationCellular Respiration Oxygen helps break down sugar to produce Oxygen helps break down sugar to produce ATP ATP

(Energy)(Energy) Without ATP, our bodies cannot make enough Without ATP, our bodies cannot make enough

energy to functionenergy to function

What is the respiratory system What is the respiratory system made of?made of? The The nose and mouthnose and mouth

Breaths air inBreaths air in The The pharynxpharynx

The large dead space behind the The large dead space behind the nosenose

The The larynxlarynx The voice box The voice box

The The tracheatrachea The largest windpipe that goes down The largest windpipe that goes down

our throatour throat Bronchi and bronchiolesBronchi and bronchioles

The smaller branches of the The smaller branches of the windpipes in your lungswindpipes in your lungs

AlveoliAlveoli Tiny grape-like sacs where diffusion Tiny grape-like sacs where diffusion

of O2 and CO2 happens in your of O2 and CO2 happens in your lungslungs

DiaphragmDiaphragm Large dome-shaped muscle at the Large dome-shaped muscle at the

base of the lungs, controls breathingbase of the lungs, controls breathing

How does air move in?How does air move in? When the When the diaphragmdiaphragm is relaxed, is relaxed,

the muscle is dome-shapedthe muscle is dome-shaped Relaxing this muscle increases Relaxing this muscle increases

pressure on the lungs, forcing the pressure on the lungs, forcing the air outair out

When the When the diaphragmdiaphragm contracts, contracts, it becomes flatit becomes flat This contraction pulls air into the This contraction pulls air into the

lungslungs Pressure decreases on the lungs Pressure decreases on the lungs

allowing them to expandallowing them to expand Even though you can control Even though you can control

your breathing, it is still your breathing, it is still mostlymostly involuntaryinvoluntary Hold your breath and see what Hold your breath and see what

happens!happens!

Relaxed Diaphragm

Contracted Diaphragm

Filtration of the Resp. SystemFiltration of the Resp. System Air first passes through the nose Air first passes through the nose

and mouthand mouth These organs warm and filter the airThese organs warm and filter the air

All of the windpipes in the All of the windpipes in the Respiratory system are lined with Respiratory system are lined with tiny hairs, called tiny hairs, called Cilia and Cilia and Mucus Mucus

CiliaCilia actively sweep out dirt, dust actively sweep out dirt, dust and smoke particlesand smoke particles

MucusMucus keeps the lungs moist keeps the lungs moist from your mouth right down to the from your mouth right down to the alveoli air sacsalveoli air sacs DIFFUSION CANNOT HAPPEN IF DIFFUSION CANNOT HAPPEN IF

THE LUNGS ARE DRY!THE LUNGS ARE DRY! Mucus also traps dirt, dust and Mucus also traps dirt, dust and

smoke before they damage the smoke before they damage the lungslungs

Cilia in the Trachea of a Rabbit

The Larynx and TracheaThe Larynx and Trachea This is the voice boxThis is the voice box

In Men, the larynx is larger, In Men, the larynx is larger, creating the creating the Adam’s AppleAdam’s Apple

The shorter the vocal The shorter the vocal chords, the deeper the voice chords, the deeper the voice and more prominent Adam’s and more prominent Adam’s AppleApple

As air passes through the As air passes through the larynx, the vocal cords larynx, the vocal cords vibrate, making a variety of vibrate, making a variety of noisesnoises SingingSinging ScreamingScreaming TalkingTalking

Right: Top-down view

Left: Side view

Bottom Left: Top of trachea

Inside the lungs: Bronchi-Inside the lungs: Bronchi-AlveoliAlveoli

The trachea branches off into two smaller airways, called The trachea branches off into two smaller airways, called Bronchi Bronchi (Bronchus is singular)(Bronchus is singular) Each bronchus branches into smaller and smaller Each bronchus branches into smaller and smaller BronchiolesBronchioles

At the end of every bronchiole is a grape-like cluster of At the end of every bronchiole is a grape-like cluster of air sacs, called air sacs, called AlveoliAlveoli The The AlveoliAlveoli is where gas exchange occurs (Diffusion) is where gas exchange occurs (Diffusion) Each Alveoli is wrapped in a net of capillaries Each Alveoli is wrapped in a net of capillaries

Bronchi + Bronchioles Alveoli

Alveoli and Cilia in a Rat Alveoli and Cilia in a Rat lunglungCross-section of AlveoliCross-section of Alveoli Cilia lining a bronchial tubeCilia lining a bronchial tube

Diffusion in AlveoliDiffusion in Alveoli As blood passes by the As blood passes by the

alveoli, it is alveoli, it is DeoxygenatedDeoxygenated (no (no oxygen in blood)oxygen in blood)

When there is lots of When there is lots of OxygenOxygen in the alveoli, is in the alveoli, is flow from flow from high to low high to low concentrationconcentration intointo the the bloodblood

Carbon dioxide does the Carbon dioxide does the opposite, flowing from opposite, flowing from high to low concentrationhigh to low concentration from the blood to the from the blood to the alveolialveoli

Tobacco and the Resp. Tobacco and the Resp. Sys.Sys.

Tobacco (found in cigarettes, dip, pipe Tobacco (found in cigarettes, dip, pipe tobacco, etc.) causes tobacco, etc.) causes MANYMANY health health problemsproblems There are over 500 known carcinogens There are over 500 known carcinogens

(cancer-causing chemicals) in cigarettes(cancer-causing chemicals) in cigarettes Most doctors believe Most doctors believe at leastat least 90% of lung 90% of lung

cancer cases are due to smokingcancer cases are due to smoking Diseases cause by smoking include:Diseases cause by smoking include:

Bronchitis, Emphysema, and Lung CancerBronchitis, Emphysema, and Lung Cancer

Diseases from SmokingDiseases from Smoking Bronchitis:Bronchitis:

Itis= inflammation, therefore, Itis= inflammation, therefore, bronchitisbronchitis is is inflammation of the bronchiinflammation of the bronchi

Mucus clogs the airways causing breathing Mucus clogs the airways causing breathing to become difficultto become difficult

The “Smoker’s cough” is often a result from The “Smoker’s cough” is often a result from thisthis

People who suffer from bronchitis often have People who suffer from bronchitis often have difficulty doing simple things like climbing difficulty doing simple things like climbing stairsstairs

More diseasesMore diseases Emphysema:Emphysema:

This is a loss of elasticity in the lung tissuesThis is a loss of elasticity in the lung tissues Normally lungs inflate like balloons, but emphysema Normally lungs inflate like balloons, but emphysema

causes stiff non-elastic scar-tissue from allowing causes stiff non-elastic scar-tissue from allowing lungs to expandlungs to expand

This is a non-reversible or curable disorderThis is a non-reversible or curable disorder Lungs lose the ability to diffuse O2 and CO2Lungs lose the ability to diffuse O2 and CO2

Lung Cancer:Lung Cancer: 180,000 people develop this disease every year, 180,000 people develop this disease every year, few few

survivesurvive It spreads very easily making it one of the most It spreads very easily making it one of the most

difficult cancers to curedifficult cancers to cure It normally takes a long time to detect it, by the time It normally takes a long time to detect it, by the time

you know you have it, it may have spread beyond a you know you have it, it may have spread beyond a point that can be curedpoint that can be cured