Respiratory System
1
Respiratory System


Main Function = gas exchange from O2 
CO2
Other functions: speech (sounds)
regulation of pH of blood.
2
Respiratory System









1. NOSE
2. NASAL CAVITY
3. PHARYNX
4. LARYNX
5. TRACHEA
6. BRONCHI
7. BRONCHIOLES
8. ALVEOLI
9. Diaphragm
3
Respiratory System
4
Figure 21.1
5
NOSE
This is there because of a number of hyaline
cartilages.
It’s fairly complex.
A cartilage nasal septum divides the right
and left sides of the nose.
Nose jobs involve taking a mallet, breaking
the nasal bone and a scalpel to shave
the cartilages.
6

Like Pinocchio, your nose shows when you
lie, http://fxn.ws/VtA93z
7

Psychology researchers from the University of Granada in Spain
used thermography to study the temperature of people's faces in
experiments. They said they found a jump in the temperature
around the nose and in the orbital muscle in the inner corner of the
eye during lying. They also found that face temperature drops for
people performing a difficult mental task and rises for people
experiencing high anxiety.
8
NASAL CAVITY
The outer skin folds into the anterior nostrils
(nares), where there are hairs which filter
large particles (insects and dust). The nasal
cavity is lined by


NASAL MUCOSA (pseudostratisfied columnar
ciliated epithelium).
9
Functions of the nasal cavity are
for the air you breathe:



Warm (cold air can freeze lungs); warmed by
superficial veins.
Clean (dirty air can clog lungs); mucous is
sticky, and cilia will move that dirt down the
back of the throat, then it’s swallowed.
Humidify (dry lungs can crack). The fluid
secreted by glands makes the moisture, even on
windy days the air goes to 100% humidity by
the time it gets to the lungs.
10
Upper Respiratory Tract
11
Figure 21.3a
Superior, middle, and inferior nasal
conchae





Covered with a mucous membrane.
Warm and moisten the air
Increase the turbulence in the flow of air
through the nasal cavity
Sensory receptors to enhance the sense of
smell.
When you have a cold and get extra fluid
(edema)  runny nose.
12

Woman's running nose revealed to be
leaking brain fluid, http://fxn.ws/Vr31JR
13
Nasal Conchae


The nasal conchae contain blood vessels
that can dilate, causing the tissue to swell,
closing off one side of your nasal airway at
a time. This allows the closed side to
increase its moisture.
Then it will open again and the other side
may close. These cycles occur every eight
hours throughout the day.
14
What causes snoring?



When we are asleep the area at the back
of the throat sometimes narrows.
The same amount of air passing through
this smaller opening can cause turbulence
in the airflow and some vibration of the
tissues in the nose and mouth.
People who snore have different reasons
for the narrowing. The narrowing can be
in the nose, mouth, or throat.
15
Snoring



Obstruction of the nasal passages can be caused
by a deviation of the nasal septum, allergies,
sinus infections, swelling of the conchae, or
large adenoids (tonsils in the back of the nose).
Those who have nasal obstructions cannot
breathe through their noses well, so they
breathe through their mouths.
Many mouth breathers snore because the flow
of air through the mouth causes greater
vibration of tissues.
16
Snoring



When we lie on our backs, gravity pulls the
palate, tonsils, and tongue backwards. This
often narrows the airway enough to cause
turbulence in airflow, tissue vibration, and
snoring.
Frequently, if the snorer is gently reminded to
roll onto his or her side, the tissues are no
longer pulled backwards and the snoring
lessens.
Some medications as well as alcohol can lead to
enhanced relaxation of muscles during sleep.
17
This will increase snoring.
18
Deviated Septum

Nasal septa which are deviated to one side
of the nasal passage can cause sinus
problems and decreased ability to smell
and taste.
A surgery can be performed to correct it:
VIDEO

http://www.youtube.com/watch?v=SP01dYof8RU


19
Septoplasty

Flexible splints
are held in
place in the
nose with a
stitch through
the hole, and
are removed
7-10 days after
surgery.
20
Apnea



An apnea is a period of time during which
breathing stops for 10+ seconds or the
breath is 25% less than normal. Apnea is
also a term for blood oxygen levels 4%
less than normal.
These episodes often occur during sleep.
The two types of sleep apnea are Central
Sleep Apnea and Obstructive Sleep Apnea.
21
Central Sleep Apnea (CSA)


Occurs when the brain does not send the
signal to breathe to the muscles of
breathing.
This usually occurs in infants or in adults
with heart disease, cerebrovascular
disease, or congenital diseases, but it also
can be caused by some medications and
high altitudes.
22
Obstructive Sleep Apnea (OSA)


People with OSA have an airway that is
more narrow than normal, usually at the
base of the tongue and palate. It is
common among adults but rare among
children.
OSA is associated with higher risks of
heart attacks and strokes because of
higher prevalence of hypertension in
individuals with obstructive sleep apnea.
23
Polyps




Nasal polyps are overgowths of the
mucosal tissue in the nasal cavities.
Usually caused from chronic allergies
Can cause difficulty breathing through
nose, loss of smell, headaches.
Treated with steroid sprays or surgery.
24
Sinuses




The nasal cavity is connected to PARANASAL
SINUSES (ETHMOID, SPHENOID,
FRONTAL, AND MAXILLARY SINUSES).
They are also lined with the same kind of
mucosa.
When you have a cold, you get stuffed up, and
the pressure can cause sinus headaches.
Some people with headaches and sinus pain
assume they have a sinus headache, but the CT
scan shows clear sinuses. They actually have a
problem with cranial nerve V, causing referred
pain to the sinuses. They need to see a
neurologist.
25
The Paranasal Sinuses
26
Figure 7.11a, b
LACRIMAL DUCT





There is another connection to the nasal
cavity: LACRIMAL DUCT.
There’s a hole in the lacrimal bone.
Excess tears drip down there.
When you cry, you get a runny nose.
If the duct overflows, you see tears on
face.
27
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 23.2b(TE Art)
Nasopharynx
Oropharynx
Laryngopharynx
LARYNX
28
Pharynx
1. NASOPHARYNX: a continuation of the nasal
cavity.
The EUSTACIAN TUBE is located here.
2. OROPHARYNX is the back of the mouth; visible
when you open your mouth and look all the way
back.
Separating the oropharanyx and the nasopharynx:
SOFT PALATE: feel it with your tongue

UVULA: located at the end of the soft palate

The function of the soft palate and uvula is to move
upward when swallowing, to prevent food from
going into nasal cavities. (They don’t close during
vomiting)
3. LARYNGOPHARYNX: This is the area of the
PHARYNX that is closest to the LARYNX.
29

Pharynx
30
Figure 21.3a
Bifurcated Uvula
31
LARYNX









It has two functions:
1. Produce sounds (vocal cords)
2. Prevent food from entering lungs
Made up of nine separate cartilages:
EPIGLOTTIS
THYROID CARTILAGE
CRICOID CARTILAGE
(2) ARYTENOID CARTILAGES
(4) Tracheal cartilages
32
Anatomy of the Larynx
33
Figure 21.5a, b
34
Glottis and Epiglottis


GLOTTIS is the opening. It stays all the way
open when you are breathing hard.
EPIGLOTTIS flaps over the glottis when you
swallow so nothing will go into the trachea.
When you get hiccoughs, it’s from a sudden
movement of air into the lungs, so the epiglottis
closes to prevent more air from going in. It’s
unknown why you get hiccoughs. All the
treatments you can try involve interrupting the
normal breathing patterns.
35
Vocal Cords
36
Figure 21.6
Vocal Cords



VOCAL CORDS (vocal folds)
Vocal cords are attached to the
ARYTENOID CARTILAGES. If these
cartilages move, the vocal cords open.
When they go back to normal, the glottis
will close.
The ability to vary the pitch of the voice
results from varying the tension in the
vocal folds.
37
Vocal Cords





For air to move through, muscles have to
contract. If muscles here are paralyzed, the
airway closes. In surgery, have to intubate. In
an emergency airway obstruction, have to do a
tracheotomy above the jugular notch.
The type of sounds you make depend on how
far apart the vocal cords are.
Way open = no sound (like when breathing)
Mostly closed = sounds
Men: their thyroid cartilage is larger, so their
vocal cords are longer = deeper voice.
38
Problems with vocal cords

LARYNGITIS: inflamed vocal cords
(↓ sound production). Usually caused from overuse
or a viral infection.


Extreme overuse (professional singers)
can get scar tissue nodules, requires
surgery.
Neurological speech evaluation VIDEO
39
Mother hears her own voice
again after nearly four years,
(text) http://fxn.ws/UElY8f

VIDEO:
http://www.myfoxatlanta.com/story/1948
8651/mother-hears-her-own-voice-againafter-nearly-four-years
40
FUN FACTS






What is the Adam's apple and what does it do?
When boys go through puberty, hormones cause the
larynx to grow rapidly, deepening their voices and
causing the bulge to form.
Enlargement of the Adam's apple is considered, like
pubic hair growth, one of the secondary sexual
characteristics.
Girls' voices also deepen with puberty, but since their
larynxes don't tend to grow as much, they don't usually
develop an "Eve's apple."
The protrusion is the thyroid cartilage.
Some folks undergo cosmetic surgery to make it less
prominent.
41
FUN FACTS



Origin of the term:
It is usually said that Adam's apple takes its name from
the biblical story about Adam, Eve. The serpent and the
apple. A piece of the forbidden fruit stuck in Adam's
throat and created the anatomic Adam's apple.
However, it may be wrong. Adam's apple in Latin is
"pomum Adami." This may have been a mistranslation of
the Hebrew "tappuach ha adam" which also means male
bump. Between Latin and English there's many a slip.
42
FUN FACTS




Why does your voice sound funny after you inhale
helium from a balloon?
Helium is lighter than air, so it causes the tissues to
vibrate faster, resulting in a higher-pitched, cartooncharacter sound.
A healthy 13-year-old boy suffered a cerebral gas
embolism after inhaling helium from a pressurized tank
at a party.
Repeated inhalation of helium can hinder your ability to
breathe.
43
TRACHEA



This is a tube that carries air from the larynx to
the lungs.
It’s fairly rigid from about 16 rings of cartilage.
The purpose of the cartilage rings is to keep the
trachea open. Otherwise, when you inhale, the
trachea would collapse like when you suck hard
on a straw. That’s why your vacuum cleaner
has rings on the hose.
44
The Trachea
45
Figure 21.7a
Histology of the trachea



MUCOSA (Inner, most superficial layer)
 EPITHELIUM (pseudostratisfied ciliated
epithelium) and goblet cells. Function of goblet
cells is to produce mucous to trap dirt. Cilia move
dirt to larynx  swallowed.
 LAMINA PROPRIA (loose connective tissue) with
lots of elastic fibers to make the trachea flexible.
SUBMUCOSA (Deep to the mucosa) This is the
serous portion to humidify the air.
ADVENTITIA (Deepest layer) This is dense
connective tissue with hyaline cartilage.
46
47
BRONCHI




The trachea branches into the RIGHT and LEFT
BRONCHUS (the primary bronchi).
These branch into the secondary bronchi, which
branch into the tertiary bronchi.
The layers become thinner, and the hyaline
cartilage no longer has nice rings; just bits.
The tertiary bronchi are microscopic. The distal
part of the tertiary bronchi are called terminal
bronchioles. These have smooth muscle and no
more bits of hyaline cartilage. Beyond them are
the respiratory bronchioles, which are where the
air sacs are.
48
49




If you inadvertently inhale something, which
lung does it go into? Right lung.
Lung cancer occurs slightly more frequently in
the right lung than in the left lung (about 53%
vs. 47% of the time). The most logical
explanation for this is that the right primary
bronchus is wider than the left one (and the
right lung is larger than the left lung), so the
right lung receives slightly more carcinogenic
cigarette smoke with each puff.
The left lung has a cardiac notch; this is where
the heart sits.
The left lung has TWO lobes, but the right lung
has THREE lobes.
50
Cardiac Notch
Cardiac Notch
51
Figure 21.8a
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Apex
Fig. 23.9b(TE Art)
Superior
lobe
Pulmonary
arteries
Secondary
bronchi
Pulmonary
veins
Hilum
Middle
lobe
Inferior
Lobe
Pulmonary
Ligament
Diaphragmatic
surface
52
BRONCHIOLES




(simple columnar epithelium, no cilia, no mucosa) The
terminal bronchioles still have a smooth muscle layer,
which functions to direct the flow of air to particular
portions of the lungs.
Right now, only a small percentage of your lungs are
needed, compared to if you are running.
Since there are no cilia, any particle that gets down that
far has to be eaten by macrophages or just stay there.
Example is a tar ball from cigarettes.
In allergic conditions, bronchioles will constrict,
blocking air flow to the lungs = ASTHMA. Asthma
can also be caused by irritants in the environment,
especially by pollution in the city. Can also be caused by
electronic cigarettes. They are better than cigarettes, but
not smoking or vaping is best.
53
Respiratory Bronchioles


Distal to the terminal bronchioles, the branches
of the respiratory tree are now called respiratory
bronchioles.
These contain alveoli (air sacs)
54
ALVEOLI



These are made of simple squamous
epithelium.
This sac is like a balloon surrounded by a
capillary bed.
Within the alveoli are macrophages and
surfactant secreting cells.
55
Alveoli
56
Figure 21.10b
Alveoli
57
Figure 21.10c, d
Fig. 23.10b
58
Healthy Alveoli
59
Alveoli with cancer
60
Respiration VIDEO 1
Respiration VIDEO 2
http://www.youtube.com/watch?v=HiT621PrrO0
61
The Respiratory Tree

As the conducting tubes of the respiratory tree
become smaller, the following changes occur
 Cartilage rings are replaced by irregular plates
of cartilage
 Cartilage disappears in the bronchioles
 The lining epithelium thins
 Elastin remains in the walls
62
FUN FACTS



Exactly what happens when you get the
wind knocked out of you?
When you get hit in the abdomen, this can
cause a pressure difference that makes your
diaphragm spasm for a few seconds.
You can't catch your breath until the spasm
stops.
63
FUN FACTS


MYTH: Cover your head or catch a cold:
Although 90% of the heat lost from the
body is lost from the head, covering your
head will not prevent this heat loss.
The heat is lost from the warm air that
you exhale.
64
65
66
67
68
Partial Pressure of Oxygen
(pO2)




The air we breath is a mixture of gasses: primarily nitrogen, oxygen,
& carbon dioxide. So, the air you blow into a balloon creates
pressure that causes the balloon to expand.
However, the total pressure generated by the air is due in part to
nitrogen, in part to oxygen, in part to carbon dioxide.
That part of the total pressure generated by oxygen is the 'partial
pressure' of oxygen, while that generated by carbon dioxide is the
'partial pressure' of carbon dioxide. A gas's partial pressure,
therefore, is a measure of how much of that gas is present (e.g., in
the blood or alveoli).
The pO2 of blood therefore refers to the amount of dissolved
oxygen in the blood plasma.
69
DIAPHRAGM


When the
diaphragm
muscle contracts,
the size of the
thoracic cavity
increases.
Pressure and
volume are
inversely related,
so air rushes into
the lungs.
70
Breathing




When the lungs inflate, the thoracic cavity
expands for two reasons:
The diaphragm pulls down, increases
volume
The rib cage expands, increases volume.
When the diaphragm contracts, the size of
the thoracic cavity increases, the pressure
inside the thoracic cavity drops, and air
flows into the lungs.
71
Inspiration


The diaphragm and
the external
intercostals are the
muscle group that
produces inspiration.
The diaphragm and
the internal
intercostals are the
muscle group that
produces expiration.
72
Changes in Thoracic Volume
73
Figure 21.15d
Pleura




Lining the thoracic cavity is PARIETAL
PLEURA.
Lining the lungs is the VISCERAL PLEURA.
Both of these are made of 2 layers (simple
squamous epi and loose fibrous ct), same as the
pericardium. Between these pleura is a tiny
space: PLEURA CAVITY.
The pleura lubricate the lungs so when the lungs
move, it is smooth. They also form an airtight
seal to allow the lungs to inflate.
74
Diagram of the Pleural Cavities
75
Figure 21.11
PNEUMOTHORAX

If there is a hole in the pleura (injury from
broken rib, knife), it’s like opening the
stopper; air flows in through the hole, and
the lungs don’t inflate =
PNEUMOTHORAX (air in thorax) 
COLLAPSED LUNG.
76
PLEURISY



The rubbing together of inflamed pleural
membranes that produces a stabbing pain
in the chest with every breath; it feels like
a broken rib.
Usually the inflammation is caused from
an infection.
It is fairly common.
77
Choking on Foreign Body
1. Encouraging the victim to cough
2. Back slaps
3. Abdominal thrusts (Heimlich
Maneuver)
 Self treatment abdominal thrusts
 Modified chest thrusts
 Finger sweeping
 Direct vision removal
 Cricothyrotomy
78
79
Cricothyrotomy
Cricothyrotomy is
easier and quicker
to perform than
tracheotomy, does
not require
manipulation of
the cervical spine,
and is associated
with fewer
complications
In cricothyrotomy, the incision or
puncture is made through the
cricothyroid membrane in between
the thyroid cartilage and the cricoid
cartilage.
80
81
Smoking Commercials

More Doctors smoke 1

http://www.youtube.com/watch?v=cKMn-_aQoPk

More Doctors smoke 2

http://www.youtube.com/watch?v=GrpmgWuwKB8
82
Lung Damage




Smoking destroys cilia, and smoke of any kind is
toxic. Particles in the lungs can’t clear.
Cigarettes contain tar, which is the same kind of
tar used to pave roads.
When there is a thin lining of tar on the alveoli,
there is no oxygen exchange to the lungs there.
Large chunks of the lung become useless.
Damage to the lungs shows up several ways.
83
CHRONIC OBSTRUCTIVE PULMONARY
DISEASE (COPD)




Number 5 killer in the USA.
It is one of two conditions:
CHRONIC BRONCHITIS: inflammation of the
bronchi, produces mucous, the openings
become smaller = obstructed.
EMPHYSEMA: scarring of elastic tissue on the
bronchioles and alveoli, which collapse now
during exhalation.

Characterized by a person with a large, “barrel” chest.
84
Barrel Chest of Emphysema
85
Barrel Chest of Emphysema
86
Emphysema




A person with emphysema is like this:
Inhale all the way, then exhale a little bit, and
hold it. Now inhale and exhale to that same
point.
They cannot exhale all the way. They start using
their abdominal and thoracic muscles, and get a
large, barrel chest.
They have chronic acid-base balance problems,
and the kidneys have to work harder. They
usually develop kidney problems.
87
Smoking





If a person stops smoking after 10 years,
damage will repair. Longer than 10 years may
have some residual damage. Smoking 20+
years is more likely to cause emphysema.
It takes 7 years for lungs to repair.
Smoking right after exercise is worse because
you are breathing more deeply.
Pollution in the air can also cause particles in the
lungs, and the ozone can damage the lungs.
Living in Southern California is like smoking one
pack a day.
A mother who smokes during pregnancy will
have a baby with a lower birth weight.
88
Smoking



Smoking also is associated with heart
disease, cancer of the lung, bladder, and
pancreas.
It also causes emphysema, pneumonia,
and bronchitis.
Some people try to quit smoking by
smoking less, trying not to inhale, or
switching to chewing tobacco, but there is
no safe way to use tobacco.
89
90
New hope for smokers who want to
quit: Electronic Cigarettes
http://www.ejuiceusa.com/



Each cartridge has enough liquid to
equal 1.5 packs of cigarettes.
These are actually water
vapor sticks…it looks and
feels like smoking, but it is
non-toxic water vapor.
Comes in various flavors
(tobacco, vanilla, fruit), and
various levels on nicotine,
from zero to strong.
Greensmoke.com
91
Good Starter Kit
Start with tobacco
flavor and high
nicotine strength.
92
More advanced
kit: battery and
juice last all day.
This is the tank.
93
This is the
battery.
94
This is the
battery charger.
95
Marijuana Vaporizer
http://www.vaporseller.com/pinnacle-proportable.html?___store=default&gclid=Cj0KEQjwt7KiBRD9lOePpe_BhrgBEiQAHaS_1Vqq_WZR3ZYR-MfMH-ipcu1VOtQoIiaITcVRVLLzr0aAk358P8HAQ
Pneumonia


An infectious illness that results in the
accumulation of fluid in the alveoli.
Pneumococcal pneumonia kills about 1 out
of 20 people who get it.
97
MRI of Lungs with Nodules
98
Respiratory Disorders

Upper Respiratory Infection (URI)




Lungs are not involved
Usually caused by a cold virus or allergies
Usually not associated with a fever (antibiotics
don’t work)
Lower Respiratory Infection (LRI)



Lungs are involved
Usually caused by bacteria
Usually associated with a fever (antibiotics
work)
99
100
Other Lung Conditions





INFLUENZA
LUNG CANCER
RESPIRATORY DISTRESS SYNDROME
TUBERCULOSIS
CYSTIC FIBROSIS
101
INFLUENZA



This is the “flu” caused by a virus.
This is what you are vaccinated against
when you get the flu vaccine.
No risks seen with flu shot in early
pregnancy http://fxn.ws/Otmu86
102
LUNG CANCER



There are many types of lung cancers.
About 150,000 die each year from them.
It is the #2 most deadly form of cancer.
85% of lung cancer is caused from
smoking.
103
LUNG CANCER



The problem is that it starts as a hard nodule
deep in the spongy tissue of the lung, where it
has no symptoms until it presses against a
structure. By then, it has also metastasized.
Surgery on a smoker won’t work because the
lungs are too weak, and they can’t do without
the lung tissue. There are no good screening
procedures for lung cancer.
In lung cancer, the cancer cells usually arise
from the epithelium lining a large bronchus.
104
Lung Cancer Surgery

Lobectomy VIDEO
105
RESPIRATORY DISTRESS
SYNDROME



SURFACTANT is a detergent produced
within the alveoli, which coats it.
It functions to help with lung inflation by
keeping the walls of the alveoli from
sticking together when they collapse
during exhalation.
If you have two wet pieces of paper and
stick them together, they are hard to pull
apart without ripping. Put soapy water
between them, and you can pull them
apart.
106
RESPIRATORY DISTRESS
SYNDROME



Surfactant is not produced in a fetus until the
ninth month, so premature babies don’t have
enough surfactant  RESPIRATORY
DISTRESS SYNDROME, which is the #1 cause
of death in premature babies.
You know how hard it is to blow up a brand new
balloon? Imagine a baby having to do that with
every single breath. You get tired.
The treatment is to spray artificial surfactant
into the lungs, and put them on a respirator to
push air in. The more distal regions are still
collapsed, so there are problems.
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TUBERCULOSIS
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An infection of a really bad bacteria that get in
the lungs and make themselves a capsule to
hide in, where antibiotics can’t reach. They set
up shop in the lungs and reproduce. Soon, the
lungs fill up with these hard nodes and make it
difficult to breathe. It causes extreme coughing,
and then lots of these bacteria break off and get
spewed into the air, where someone else can
inhale them. It is extremely contagious and very
deadly.
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TUBERCULOSIS
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If a person gets TB, the State Health Department has to be
notified.
If it is active TB, you must be hospitalized.
If it is not an active infection, you still need medicines.
They will show up at your house every morning for six
months and stand there and watch you take your pills.
If you don’t accept this, they have the right to haul you
away to a lock-up facility and force the medicine in you for
six months.
There are only a few diseases where the State Health
Department will step in like this: anthrax, small pox, swine
flu, typhoid fever, bubonic plague, and Ebola virus are other
diseases where you don’t get a choice; you are forced into
isolation. Diseases like TB and the plague have almost
wiped out Europe!
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Positive TB skin test
http://www.visualsunlimited.com/
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TUBERCULOSIS
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A TB test will be positive if you have been exposed to
the organism at any point in your life.
Then you’ll have to go in for an x-ray to see if it is an
active case of TB or not.
Once you recover from TB you will always have a
positive TB test, so tell the nurse that in advance.
You may have to provide documentation that you have
been treated for it already.
Most employers require TB tests before hiring. I had to
take one to work here.
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CYSTIC FIBROSIS
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Cystic fibrosis is an
inherited disease that
causes thick, sticky
mucus to build up in the
lungs and digestive
tract. It is one of the
most common type of
chronic lung disease in
children and young
adults, and may result in
early death.
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CYSTIC FIBROSIS

Millions of Americans carry the defective CF
gene, but do not have any symptoms. That's
because a person with CF must inherit two
defective CF genes -- one from each parent. An
estimated 1 in 29 Caucasian Americans have the
CF gene. The disease is the most common,
deadly, inherited disorder affecting Caucasians
in the United States. It's more common among
those of Northern or Central European descent.
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CYSTIC FIBROSIS
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Most children with CF are diagnosed by
age 2. A small number, however, are not
diagnosed until age 18 or older. These
patients usually have a milder form of the
disease.
Having CF offers some protection from
typhoid fever and cholera, in the same
way that sickle cell anemia protects
against malaria.
114
Choking Hazards for Children
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http://www.kidsdr.com/daily-dose/hotdogs-a-choking-hazard
Tonsillectomy VIDEO
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