Respiratory AnatomyRespiratory Anatomy

Interesting FactsInteresting Facts

The surface area of the lungs is about the The surface area of the lungs is about the same size as a tennis courtsame size as a tennis court

You lose about ½ L of water a day through You lose about ½ L of water a day through breathingbreathing

Tuberculosis (TB) is caused by bacteria Tuberculosis (TB) is caused by bacteria that destroy the air sacs in the lungsthat destroy the air sacs in the lungs

2 million people die of TB each year2 million people die of TB each year

Lizards can’t breathe when they are Lizards can’t breathe when they are running . . . their breathing depends on the running . . . their breathing depends on the muscles between their ribs which MUST muscles between their ribs which MUST be used during runningbe used during running

The vapour that comes out of your mouth The vapour that comes out of your mouth when you cough travels at about 160 km/hwhen you cough travels at about 160 km/h

Some animals (some frogs) can breathe Some animals (some frogs) can breathe through their skinthrough their skin

One acre of trees produces enough One acre of trees produces enough oxygen to keep 18 people alive for one oxygen to keep 18 people alive for one yearyear

Cigarettes and cigarette smoke contain Cigarettes and cigarette smoke contain over 4000 chemicals, including 43 known over 4000 chemicals, including 43 known to cause cancerto cause cancer

Every cigarette shortens your life by ~14 Every cigarette shortens your life by ~14 minutesminutes

The need for oxygenThe need for oxygen

Humans need oxygen to survive (250 Humans need oxygen to survive (250 mL/min). mL/min).

We can live several days without water, We can live several days without water, weeks without food, but only minutes weeks without food, but only minutes without oxygenwithout oxygen

Composition of atmosphere: 78% nitrogen, Composition of atmosphere: 78% nitrogen, 21% oxygen, 0.03% carbon dioxide21% oxygen, 0.03% carbon dioxide

Cells obtain energy by breaking down Cells obtain energy by breaking down sugars; oxygen is needed for this to sugars; oxygen is needed for this to happenhappen

The process of breaking down sugars into The process of breaking down sugars into energy is called cellular respiration:energy is called cellular respiration:

CC66HH1212OO66 + 6O + 6O22 → 6H → 6H22O + 6COO + 6CO22 + energy + energy

The opposite is photosynthesisThe opposite is photosynthesis

Nasal/oral cavityNasal/oral cavity -> -> pharynx -> epiglottis -> larynx pharynx -> epiglottis -> larynx

-> trachea -> bronchi -> -> trachea -> bronchi -> bronchioles -> alveolibronchioles -> alveoli

Air enters through the nasal cavities or the Air enters through the nasal cavities or the mouth. Three important things happen:mouth. Three important things happen: Foreign particles are prevented from entering Foreign particles are prevented from entering

because of tiny hairs. because of tiny hairs. (Filtered)(Filtered) Air is Air is warmedwarmed and and moistenedmoistened as it enters the as it enters the

body.body.

From the nasal cavity, air travels through From the nasal cavity, air travels through the the pharynxpharynx (air filled channel in the (air filled channel in the mouth) into the mouth) into the larynxlarynx through the through the epiglottis. epiglottis.

Your tonsils are located in the pharynxYour tonsils are located in the pharynx

Nasal/oral cavity ->Nasal/oral cavity -> pharynx pharynx -> epiglottis -> larynx -> epiglottis -> larynx -> trachea -> bronchi -> bronchioles -> alveoli-> trachea -> bronchi -> bronchioles -> alveoli

Nasal/oral cavity ->Nasal/oral cavity -> pharynxpharynx -> -> epiglottisepiglottis -> larynx -> larynx -> trachea -> bronchi -> bronchioles -> alveoli-> trachea -> bronchi -> bronchioles -> alveoli

The pharynx also opens into the The pharynx also opens into the esophagus esophagus where food travels to the stomach.where food travels to the stomach.

When food is chewed, it is forced to the top of When food is chewed, it is forced to the top of the mouth, and pushed backwards. This forces the mouth, and pushed backwards. This forces the the epiglottisepiglottis to close, allowing food to enter the to close, allowing food to enter the esophagus, not the trachea. esophagus, not the trachea.

If you swallow too fast, cilia (hair-like protein If you swallow too fast, cilia (hair-like protein structures) push particles out of respiratory tract structures) push particles out of respiratory tract and force a violent cough. and force a violent cough.

Nasal/oral cavity ->Nasal/oral cavity -> pharynx -> epiglottis -> pharynx -> epiglottis -> larynxlarynx -> trachea -> bronchi -> bronchioles -> alveoli-> trachea -> bronchi -> bronchioles -> alveoli

Air travels through the Air travels through the larynxlarynx, commonly called , commonly called the the voice boxvoice box. .

Elastic ligaments create sound when air from the Elastic ligaments create sound when air from the lungs is forced towards the pharynx. lungs is forced towards the pharynx.

The larynx is protected by a thick band of The larynx is protected by a thick band of cartilage, commonly called the Adam’s Apple. cartilage, commonly called the Adam’s Apple. The growth of this cartilage and larynx during The growth of this cartilage and larynx during puberty cause the deep voices of males.puberty cause the deep voices of males.

Nasal/oral cavity ->Nasal/oral cavity -> pharynx -> epiglottis -> larynx pharynx -> epiglottis -> larynx -> -> trachea -> bronchi -> bronchiolestrachea -> bronchi -> bronchioles -> alveoli -> alveoli

Air travels through the Air travels through the tracheatrachea (12 cm (12 cm longs) and through longs) and through right and left bronchiright and left bronchi. . These structures contain cartilaginous These structures contain cartilaginous rings for support.rings for support.

The The tracheatrachea is know as the is know as the wind pipewind pipe

The bronchi lead to the right and left lung, The bronchi lead to the right and left lung, leading air into the leading air into the bronchiolesbronchioles..

Nasal/oral cavity ->Nasal/oral cavity -> pharynx -> epiglottis -> larynx pharynx -> epiglottis -> larynx -> trachea -> bronchi -> bronchioles -> -> trachea -> bronchi -> bronchioles -> alveolialveoli

The bronchioles lead to the The bronchioles lead to the alveolialveoli.(air .(air sacs)sacs)

The The alveolialveoli are surrounded by capillaries. are surrounded by capillaries. It is here where oxygen and carbon It is here where oxygen and carbon dioxide exchange takes place. dioxide exchange takes place.

The LungsThe Lungs

Well protected by the ribs, sternum and Well protected by the ribs, sternum and spinespine

Contained within the Contained within the pleurapleura, 2 , 2 membranous sacs which surround the membranous sacs which surround the lungslungs

The pleura help to isolate each lungThe pleura help to isolate each lung

For air to enter the lungs, 2 basic actions For air to enter the lungs, 2 basic actions must occur:must occur:

1.1. The diaphragm – a thin, dome shaped sheet The diaphragm – a thin, dome shaped sheet of muscleof muscle

– – as we breathe in, the sheet is pulled as we breathe in, the sheet is pulled downward (flattens it out)downward (flattens it out)

2. The second action causes the rib cage to 2. The second action causes the rib cage to move upward and outwardmove upward and outward

– – this results in contraction of the intercostals this results in contraction of the intercostals muscles which lie between the ribsmuscles which lie between the ribs

Inspiration (breathing in)Inspiration (breathing in)

The volume of the lungs increases as the The volume of the lungs increases as the chest wall moves upward and outward, chest wall moves upward and outward, and the diaphragm moves downwardand the diaphragm moves downward

As the volume increases, pressure As the volume increases, pressure decreases; as the pressure decreases, air decreases; as the pressure decreases, air rushes in to equalize the pressure inside rushes in to equalize the pressure inside the lungsthe lungs

The process of inspiration requires that The process of inspiration requires that muscles actively contractmuscles actively contract

Expiration (breathing out)Expiration (breathing out)

As the diaphragm relaxes, it pushes up to As the diaphragm relaxes, it pushes up to regain its shaperegain its shape

The intercostals muscles in the chest wall The intercostals muscles in the chest wall relax and the ribs move down and inwardrelax and the ribs move down and inward

These movements decrease the volume of These movements decrease the volume of the lungs, the pressure inside increases the lungs, the pressure inside increases which pushes air out of the lungs until the which pushes air out of the lungs until the internal and external pressure are equal internal and external pressure are equal once moreonce more

Breathing out requires no muscle Breathing out requires no muscle contraction – it is just the result of muscle contraction – it is just the result of muscle relaxationrelaxation

Lung CapacityLung Capacity

Healthy adult – average 14-20 breathes Healthy adult – average 14-20 breathes per minuteper minute

The amount of air moved by a normal The amount of air moved by a normal individual breathing while at rest is called individual breathing while at rest is called the the tidal volumetidal volume – this is only a portion of – this is only a portion of the potential lung capacity the potential lung capacity

If you forcibly push out as much air as you If you forcibly push out as much air as you can, the air you remove is called the can, the air you remove is called the expiratory expiratory reserve volumereserve volume

Similarly the amount of extra air you can Similarly the amount of extra air you can forcibly pull in is the forcibly pull in is the inspiratory reserve inspiratory reserve volumevolume

These three volumes together make up These three volumes together make up the the vital capacityvital capacity of the lungs of the lungs

No matter how hard you try to push air out No matter how hard you try to push air out of the lungs, there will always be a small of the lungs, there will always be a small amount left in the spaces and tubes – amount left in the spaces and tubes – called called residual air capacityresidual air capacity

Structure and FunctionStructure and Function

The structure The structure and and functionfunction of of the respiration the respiration tract is to tract is to maximize air maximize air exchangeexchange, and , and minimize foreign minimize foreign particles from particles from entering the entering the lungs. lungs.

Repiratory system with the Repiratory system with the Circulatory SystemCirculatory System

Respiratory system brings oxygen into the Respiratory system brings oxygen into the bodybody

Oxygen will cross the membranes, enter Oxygen will cross the membranes, enter the bloodstream, and be transported to the the bloodstream, and be transported to the cells which require oxygen for their cells which require oxygen for their activitiesactivities