Transcript Respiratory System

CHAPTER
24
The Respiratory
System
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-2
Learning Outcomes
24.1 Explain the functions of the respiratory
system.
24.2 Explain the difference between internal
respiration and external respiration.
24.3 Describe how the larynx produces voice
sounds.
24.4 List the structures contained within the lungs.
24.5 Describe the coverings of the lungs and
chest cavity.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-3
Learning Outcomes (cont.)
24.6 Describe the events that lead to the
inspiration and expiration of air.
24.7 Explain how the brain controls breathing and
how normal breathing patterns can be
disrupted.
24.8 Describe how oxygen is transported from the
lungs to body cells.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-4
Learning Outcomes (cont.)
24.9 Describe how carbon dioxide is transported
from body cells to the lungs.
24.10List and explain various respiratory volumes
and tell how they are used to diagnose
respiratory problems.
24.11Describe the causes, signs and symptoms,
and treatments of various diseases and
disorders of the respiratory system.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-5
Introduction
• Function
– Move air in and out of lungs (ventilation)
– Delivers oxygen (O2)
– Removes carbon dioxide (CO2)
CO2
• External respiration
– Occurs in the lungs
• Internal respiration
– Occurs in the hemoglobin
O2
O2
Lungs
CO2
CO2
O2
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-6
Organs of the Respiratory System

Nose

Pharynx

Larynx

Trachea

Bronchial tree

Lungs
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-7
Nasal Cavity
• Nasal septum divides the cavity into right and
left portions
– Nares – openings of the nose
• Nasal conchae extend from walls of nasal
cavity
• Mucous membrane warms and moistens the air
• Cilia help eliminate particles
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-8
Paranasal Sinuses
• Air-filled spaces within
the skull bones
– Open into the nasal
cavity
• Reduce the weight of
the skull
• Equalize pressure
• Give the voice its
certain tone
• Skull bones with
sinuses include:
–
–
–
–
Frontal
Sphenoid
Ethmoid
Maxillae bones
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-9
Pharynx and Larynx
•
Pharynx
– Serves both the respiratory and digestive systems
• Larynx
– Also called the “voice box”
– Moves air in and out of the trachea and
produces voice
– Composed of three cartilages:
• Thyroid cartilage
• Epiglottic cartilage
• Cricoid cartilage
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-10
Vocal Cords
• Stretched between the
thyroid cartilage and Posterior
the cricoid cartilage Portion
• Upper – false cords
of
Tongue
• Lower – true vocal
cords
• Glottis – the opening
between the vocal
cords
Glottis
False
Vocal
Cords
True
Vocal
Cords
• Stretch = pitch of
voice
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-11
Trachea
• Referred to as the windpipe
• Tubular organ made of rings of
cartilage and smooth muscle
• Extends from the larynx to the
bronchi
• Lined with cells possessing
cilia (microscopic hair-like projections)
Trachea
Cilia move mucus up to the throat, where
it is swallowed. Smoking destroys cilia.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-12
Bronchial Tree
• Bronchi
Bronchi
– Primary: First
branches off
trachea
– Secondary
– Tertiary
• Bronchioles
– Branch off tertiary
bronchi
Bronchioles
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-13
Bronchial Tree (cont.)
• Alveoli
– Thin sacs of cells
surrounded by
capillaries
– Secrete surfactant
• Fatty substance
• Helps maintains the
inflation of the
alveoli between
inspirations
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-14
Lungs
• Cone-shaped organs
• Right lung – three lobes
• Left lung – two lobes
• Pleura – membranes surrounding the
lungs
The lungs contain connective tissue, the bronchial
tree, nerves, lymphatic vessels, and blood vessels.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-15
Apply Your Knowledge
Which of the following sites would be the most
lethal if obstructed by a foreign body?
ANSWER:
a. Right bronchus
b. Left bronchus
c. Trachea
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-16
The Mechanisms of Breathing
Inspiration
 Air rich in O2 enters the lungs
from the atmosphere
 The diaphragm contracts or
Expiration
 Air rich in C02 exits the lungs
 The diaphragm relaxes
 The intercostal muscles lower
flattens
 The intercostal muscles raise
the ribs
the ribs
Breathing, or pulmonary ventilation, consists of inspiration
(inhalation) and expiration (exhalation).
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-17
The Mechanisms of Breathing (cont.)
• Respiratory center
of the brain
• Other factors
– CO2 levels in the blood
– Medulla oblongata –
controls rhythm and
depth of breathing
– pH of the blood
– Pons – controls the
rate of breathing
– Inflation reflex
– Fear and pain
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-18
The Mechanisms of Breathing (cont.)
• Causes of altered breathing patterns
– Coughing
– Sneezing
– Laughing
– Crying
– Hiccups
– Yawning
– Speaking
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-19
Apply Your Knowledge
Indicated whether each statement refers to (I) inhalation
or (E) exhalation:
ANSWER:
__
E The intercostal muscles lower the ribs
I The diaphragm contracts or flattens
__
I The intercostal muscles raise the ribs
__
__
E The diaphragm relaxes
I Air rich in O2 enters the lungs from the atmosphere
__
E Air rich in C02 exits the lungs
__
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-20
The Transport of Oxygen and Carbon Dioxide
in the Blood
•
Most of the oxygen
binds to hemoglobin
– Oxyhemoglobin
– Bright red in color
•
Some oxygen remains
dissolved in plasma
• If CO2 combines with hemoglobin at O2
sites, it forms carboxyhemoglobin
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-21
The Transport of Oxygen and Carbon Dioxide
in the Blood (cont.)
•
Carbon dioxide gets into the bloodstream
– Reacts with water in plasma and forms
carbonic acid
– Carbonic acid ionizes and releases hydrogen
and bicarbonate ions
– Bicarbonate ions attach to hemoglobin
•
Exhaled as waste product in the lungs
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-22
Apply Your Knowledge
Describe what happens to carbon dioxide in the
blood.
ANSWER: Carbon dioxide can combine with hemoglobin
and form carboxyhemoglobin. Most reacts with water in
plasma to form carbonic acid. The carbonic acid ionizes
and releases hydrogen and bicarbonate ions. The
bicarbonate ions then attach to hemoglobin and are
exhaled as a waste product from the lungs.
Super!
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-23
Respiratory Volumes
• Different volumes of
air move in and out of
lungs with different
intensities of
breathing
• Measured to assess
health of respiratory
system
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-24
Respiratory Volumes (cont.)
Tidal Volume
Amount of air that moves in or out of the
lungs during a normal breath
Inspiratory
Reserve
Volume
Amount of air that can be forcefully
inhaled following a normal inhalation
Expiratory
Reserve
Volume
Amount of air that can be forcefully
exhaled following a normal exhalation
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-25
Respiratory Volumes (cont.)
Residual
Volume
Volume of air that always remains in
the lungs even after a forceful
exhalation
Vital
Capacity
Amount of air that can be forcefully
exhaled after the deepest inhalation
possible
Total Lung
Capacity
The total amount of air the lungs can
hold
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-26
Apply Your Knowledge
Match the following:
ANSWER:
C Amount of air that moves during
___
a normal breath
B Amount of air that always
___
remains in the lungs
A Total amount of air the lungs
___
can hold
D Amount of air forcefully exhaled
___
after deepest inhalation possible
A. Total lung
capacity
B. Residual volume
C. Tidal volume
D. Vital capacity
Good Job!
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-27
Snoring
•
•
•
Due to vibration of soft
tissues when muscles of
the palate, tongue, and
throat relax
Affects approximately
50% of men and 25% of
women over the age of
40
Causes daytime
sleepiness
• Common Causes
– Enlargement of tonsils
or adenoids
– Being overweight
– Alcohol consumption
– Nasal congestion
– Deviated nasal
septum
– May be associated with
obstructive sleep apnea
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-28
Snoring (cont.)
Mayo Clinic’s Sleep Disorders Center rating
of snoring:
Heard from close proximity
Heard from anywhere in the bedroom
Heard from just outside the bedroom door
with door open
Heard outside the bedroom door with the
door closed
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-29
Snoring (cont.)
• Lifestyle modifications to reduce snoring
–
–
–
–
–
Lose weight
Change sleeping position
Avoid using alcohol or medications that induce sleep
Use nasal strips to widen the nasal passages
Use dental devices to keep airways open
• Treatments
– CPAP
– Surgery (uvulotomy)
– Laser surgery
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-30
Common Diseases and Disorders
Disease
Description
Allergic
rhinitis
Hypersensitivity reaction to various airborne
allergens
Asthma
A condition in which the tubes of the
bronchial tree become obstructed due to
inflammation
Collapsed lung
Atelectasis
Bronchitis
Inflammation of the bronchi often follows a
cold; one type of COPD
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-31
Common Diseases and Disorders (cont.)
Disease
Description
Chronic
obstructive
pulmonary
disease (COPD)
A group of lung disorders that limit
airflow to lungs and usually cause
enlargement of the alveoli
Emphysema
A chronic condition associated with
smoking that damages the alveoli; one
type of COPD
Influenza
A viral disease that attacks the
respiratory system; commonly called
the flu
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-32
Common Diseases and Disorders (cont.)
Disease
Description
Laryngitis
An acute inflammation of the larynx
causing hoarseness (dysphonia)
Legionnaire’s
Acute bacterial pneumonia caused by
disease
Legionnaire bacteria that usually grows
in the standing water of air conditioning
systems
Lung cancer
Cancer closely associated with smoking
and exposure to second-hand smoke;
four types of lung cancers
Pleural effusion A buildup of fluid in the pleural cavity
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-33
Common Diseases and Disorders (cont.)
Disease
Description
Pleuritis/Pleurisy Inflammation of the membranes that
cover the lungs, known as pleura
Pneumoconiosis
Pneumonia/
Pneumonitis
Lung diseases that result from years
environmental or occupational
exposure to different types of dust;
three types
An inflammation of the lungs that is
most often caused by a bacterial, viral,
or fungal infection
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-34
Common Diseases and Disorders (cont.)
Disease
Description
Pneumothorax
A collection of air in the chest around the
lungs, which may cause atelectasis
Pulmonary
edema
A condition in which fluids fill spaces
within the lungs, making it very difficult for
the lungs to oxygenate the blood
Pulmonary
embolism
A blood clot (embolism) that travels
usually from the legs and blocks an artery
in the lungs
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-35
Common Diseases and Disorders (cont.)
Disease
Description
Respiratory
distress
syndrome (RDS)
Syndrome in which a lack of surfactant
in the lungs allows the alveoli to
collapse on exhalation, resulting in poor
oxygenation
A viral respiratory disease that is very
contagious and sometimes fatal
Severe acute
respiratory
syndrome
(SARS)
Sinusitis
An inflammation of the membranes
lining the sinuses of the skull
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-36
Common Diseases and Disorders (cont.)
Disease
Sudden infant
death syndrome
(SIDS)
Tuberculosis
Description
A syndrome without characteristic signs
or symptoms; usually a baby with this
disorder simply goes to sleep and
never wakes up
Primarily a respiratory disease caused
by various strains of the bacterium
Mycobacterium tuberculosis
Upper respiratory Coryza, or the common cold
(tract) infection
(URI)
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-37
Apply Your Knowledge
The medical assistant working for a general practitioner is
taking the medical history of a new patient. The patient
states, “Even after sleeping 8 to 9 hours, I still feel really
tired.” The patient’s spouse states, “Well, you sure snore
loud, as if the sleep is so good.” Which of the following is a
possible cause for the excessive fatigue?
ANSWER:
a. Sleep apnea
b. Depression
c. Tuberculosis
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-38
In Summary
24.1 The function of the respiratory system is to move air
in and out of the lungs in a process known as
ventilation, respiration, or breathing.
24.2 The exchange of oxygen and carbon dioxide in the
lungs is called external respiration. The same
exchange within the hemoglobin of red blood cells is
internal respiration.
24.3 The larynx contains the vocal cords, which stretch
between the thyroid and cricoid cartilages. The
muscles of the lower (true) vocal cords stretch and
relax them to produce different sounds.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-39
In Summary (cont.)
24.4 The lungs contain connective tissue, the bronchial
tree, nerves, lymphatic vessels, and blood vessels.
The left lung consists of two lobes (upper and lower),
and the right lung consists of three lobes (upper,
middle, and lower).
Within each lung are the primary, secondary, and
tertiary branches of the bronchi, the bronchioles, and
the alveoli.
24.5 The lungs are covered by, and the chest cavity is
lined with, the pleura. The outer membrane is the
parietal pleura and the inner membrane is the visceral
pleura.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-40
In Summary (cont.)
24.6 During inspiration, the diaphragm contracts and the
intercostal muscles raise the ribs, increasing the
space in the thoracic cavity.
This decreases the pressure within the cavity so that
the air outside the body passively flows into the
thoracic cavity.
During expiration, the diaphragm relaxes, pushing up
into the thoracic cavity, and the intercostal muscles
lower the ribs, forcing the air to flow out of the body.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-41
In Summary (cont.)
24.7 Breathing is controlled by the respiratory center of the
brain located in the pons and medulla oblongata.
Carbon dioxide levels and pH levels of the blood also
affect breathing. Everyday situations such as
coughing, sneezing, laughing, crying, hiccups,
yawning, and speaking also alter breathing patterns.
24.8 Most of the oxygen in the bloodstream binds to the
hemoglobin within red blood cells, resulting in
oxyhemoglobin, although a small amount does not
bind to hemoglobin and remains dissolved in the
plasma.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-42
In Summary (cont.)
24.9 Carbon dioxide binds to hemoglobin, resulting in
carboxyhemoglobin.
Most of the carbon dioxide that enters the body reacts
with water in blood and cerebral spinal fluid to form
carbonic acid.
As carbonic acid ionizes, it releases hydrogen and
bicarbonate ions, which attach to hemoglobin making
its way back to the lungs to be exhaled.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-43
In Summary (cont.)
24.10 Respiratory volumes are measured to check the
health of the respiratory system.
The volumes are listed here and the normal
capacities are found in the chapter: tidal volume,
inspiratory and expiratory reserve volumes, residual
volume, inspiratory capacity, functional residual
capacity, vital capacity, and total lung capacity.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-44
In Summary (cont.)
24.11 The diseases and disorders of the respiratory system
are many and varied, as are the causes and
treatments of these diseases. Many of the more
common respiratory disorders, with their individual
causes and treatments, are discussed in detail in the
Pathophysiology section of this chapter.
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.
24-45
End of Chapter 24
The air of ideas is
the only air worth
breathing.
~Edith Wharton
© 2011 The McGraw-Hill Companies, Inc. All rights reserved.