Transcript Respiratory system - Napa Valley College

Respiratory System
Biol 105
Lecture 18
Chapter 14
Outline - Respiratory System
I.
II.
III.
IV.
V.
Function of the respiratory system
Parts of the respiratory system
Mechanics of breathing
Regulation of breathing
Disorders of the respiratory system
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Respiratory system Function
 The function of the respiratory system is to
bring in oxygen to the body and remove
carbon dioxide.
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The Respiratory System
Breathing moves air
in and out of the lungs.
External respiration
is the exchange of
oxygen and carbon
dioxide between the
lungs and the blood.
Gas transport
moves oxygen and
carbon dioxide
between the lungs
and the body tissues.
Internal respiration is
the exchange of oxygen
and carbon dioxide
between blood and the
body tissues.
Oxygen
transport
Lungs
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Gas diffusion
Carbon
dioxide
transport
Gas diffusion
Tissue
Figure 14.1
This type of tissue covers and lines body parts
1.
2.
3.
4.
Connective
Epithelial
Muscle
Nervous
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Cells lining respiratory tract
 Lined by pseudostratified ciliated columnar
epithelial cells. The cilia sweeps mucus,
germs and debris toward the throat.
 Mucas produced by goblet cells.
 Smoking damages the ciliated cells
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8-4
The Respiratory System
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Figure 14.4a
Ciliated cells in respiratory tract
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The Respiratory System
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Figure 14.3
The Respiratory System
UPPER RESPIRATORY
SYSTEM
• Filters, warms, and
moistens air
Sinuses
• Cavities in skull
• Lighten head
• Warm and moisten
air
Nasal cavity
• Produces mucus
• Filters, warms, and
moistens air
• Olfaction
Pharynx
• Passageway for
air and food
RESPIRATORY
MUSCLES
• Cause breathing
Intercostal
muscles
• Move ribs during
breathing
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Diaphragm
• Muscle sheet between
chest and abdominal
cavities with a role in
breathing
Figure 14.2 (1 of 2)
The Respiratory System
LOWER RESPIRATORY
SYSTEM
• Exchanges gases
Larynx
• Air passageway
• Prevents food and drink
from entering lower
respiratory system
• Produces voice
Bronchi
• Two branches of
trachea that conduct
air from trachea to
each lung
Bronchioles
• Narrow passageways
to conduct air from
bronchi to alveoli
Epiglottis
• Covers larynx during
swallowing
Lungs
• Structures that contain
alveoli and air
passageways
• Allow exchange of
oxygen and carbon
dioxide between
atmosphere and blood
Trachea
• Connects larynx with
bronchi leading to
each lung
• Conducts air to and
from bronchi
Alveoli
• Microscopic chambers
for gas exchange
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Figure 14.2 (2 of 2)
1. Nasal cavity
 Functions:
1. filter
2. warm
3. moisten the air entering the lungs
4. smell
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8-3
1. Nasal cavity
 Parts of the nasal cavity:
 Mucus membranes - secrete sticky mucus
to trap germs & debris.
 Contains olfactory receptor cells for the
sense of smell
 Sinuses – air filled cavities, warm and
moisten air
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8-3
2. Pharynx
 Functions - is a passageway for air,
liquids, and food. (swallowing begins
here). Connects the nasal cavity to the
esophagus and the larynx
 Tonsils are found here – lymphatic tissue
that protects against infection
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8-4
3. Larynx
 Functions
1. Connects the pharynx to the
trachea
2. Contains vocal cords used to
generate sound
3. Prevents food from entering lower
respiratory tract
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8-4
3. Larynx
 Structure made from cartilage
 Epiglottis closes the trachea when
swallowing
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8-4
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4. Trachea
 Windpipe held open by concentric rings of
cartilage
 Function – Connects the larynx to the
bronchi.
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8-4
Bronchial Tree
Trachea leads to the bronchial tree:
 Bronchi (bronchus)
 Bronchioles
 Alveoli (alveolus).
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8-4
The Respiratory System
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Figure 14.7
7. Alveoli
 Sacs at the end of the bronchioles, they are
surrounded by blood capillaries .
 Function: It is here that the oxygen diffuses
across the membrane into the capillaries, and
carbon dioxide goes from the capillaries to the
inside of the lungs.
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8-6
Alveoli
 Lungs - have about 300 million alveoli
 The structure of the alveoli increases
surface area of lung
 For alveoli to function properly they are
coated with phospholipid molecules called
surfactant that keep them open
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Alveoli
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Figure 14.8
The Respiratory System
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Table 14.1 (1 of 2)
The Respiratory System
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Table 14.1 (2 of 2)
What cells secrete mucus
1.
2.
3.
4.
Cilliated columnar epi
goblet
Squamous epi
osteocytes
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The tube connecting the larynx to the primary
bronchi is
1.
2.
3.
4.
pharynx
trachea
bronchioles
alveoli
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Common passageway for air, food and drink
1.
2.
3.
4.
pharynx
trachea
bronchioles
alveoli
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Conduct air from the trachea to the bronchioles
1.
2.
3.
4.
pharynx
trachea
bronchi
alveoli
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Gas exchange takes place here
1.
2.
3.
4.
pharynx
trachea
bronchioles
alveoli
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Which cavity is the lung located in?
1.
2.
3.
4.
Abdominal
Pericardial
Pleural
Dorsal
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Inhalation
Inhalation
Rib cage
moves up
and out
Air flow
Intercostal
muscles
contract
Diaphragm
contracts
and flattens
The chest cavity increases
in size, and pressure within
the lungs decreases.
Diaphragm
contracts
The lungs expand, and
air moves in.
(a)
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Figure 14.9a
Inhalation
 When the diaphragm and intercostal muscles
contract, the volume of the thoracic cavity
increases, causing the pressure in the lungs to
decrease
 Inhalation is also called inspiration
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Exhalation
Exhalation
Air flow
Rib cage
moves down
and inward
Intercostal
muscles relax
Diaphragm
relaxes and
moves upward
The chest cavity decreases
in size, and pressure
within the lungs increases.
Diaphragm
relaxes
The lungs recoil,
and air moves out.
(b)
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Figure 14.9b
Exhalation
 Exhalation = Expiration
 When the same muscles relax, volume of
the thoracic cavity decreases, pressure in
the lungs increase
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Air Volumes
 The volume of air inhaled or exhaled
during a normal breath is called the tidal
volume
 Tidal volume is usually around 500 ml
 The volume of air moved into and out of
the lungs is an indication of health
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Air Volumes
 Inspiratory reserve volume = forced inhalation
volume
 Expiratory reserve volume = forced exhalation
volume
 Residual volume is the amount of air left in the
lungs after forced exhalation
 Vital capacity is the amount of air brought in
and out of the lungs during forced breathing
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Air Volumes
6000
Inspiratory
reserve
(forced
inhalation)
volume
Lung Volume (ml)
5000
4000
Total
lung
capacity
Vital
capacity
Tidal volume
3000
2000
Expiratory reserve
(forced exhalation)
volume
1000
Residual
volume
0
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Figure 14.10 (1 of 2)
Gas Exchanges in the Body
 Remember that O2 enters and CO2 leaves the
lungs = External respiration
 Then O2 and CO2 is exchanged between the
blood vessels and tissues = Internal Respiration
 This gas exchange is due to diffusion
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8-14
Oxygen Transport
 Oxygen is transported on Hemoglobin.
 When Oxygen is bound to hemoglobin, then it is
called Oxyhemoglobin
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8-15
Carbon Dioxide Transport
1. CO2 is transported dissolved in the plasma (10%)
2. CO2 is bound to hemoglobin (20%)
3. CO2 is converted to bicarbonate ions (70%)
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8-14
Bicarbonate ions
CO2 + H2O
Carbonic
anhydrase
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H2CO3
H+ + HCO3-
8-14
Diffusion of Gasses: Alveoli and Capillaries
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Figure 14.11 (2 of 2)
Diffusion of Gasses: Capillaries and Tissues
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Figure 14.11 (1 of 2)
Regulation of Breathing
 Normally we breath 12 - 15 ventilations per
minute.
 This rate is controlled by the medulla oblongata
region of the brain. Nerves transmit signal to the
diaphragm and muscles.
 Chemoreceptors in the medulla oblongata and
arteries detect levels of CO2 and O2 in the blood,
controlling the rate and depth of breathing.
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8-12
Respiratory Disorders









Common cold
Flu
Pneumonia
Strep Throat
Tuberculosis
Bronchitis
Asthma
Emphysema
Lung Cancer
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8-16
Respiratory Disorders – Common Cold
 The common cold - Caused by several types
of viruses.
 Symptoms: runny nose, sore throat, sneezing,
nasal discharge
 Treatment: rest and plenty of fluids
 Prevention: wash your hands
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Respiratory Disorders - Flu
 The flu is caused by the Influenza viruses but
there are many variants of these viruses
 Symptoms: Similar to colds but appear suddenly
and more severe. Usually have fever and chills,
may have muscle aches, headache, and
weakness.
 Treatment and prevention – same as cold
 Can take drugs to ease symptoms and antiviral
medications may ease symptoms
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Respiratory Disorders - Pneumonia
 Pneumonia is an inflammation of the lungs that
causes fluid to accumulate in the alveoli,
reducing gas exchange
 Usually caused by a viral or bacterial infection
 Symptoms: fever, chills, chest pain, cough,
shortness of breath.
 Treatment depends on cause – bacteria can be
treated with antibiotics.
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Respiratory Disorders Strep throat
 Strep throat is caused by Streptococcus
bacteria
 Can lead to rheumatic fever which can
damage heart and kidney disease
 Symptoms: Sore throat accompanied by
swollen glands and fever
 Treatment: antibiotics
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Respiratory Disorders - Tuberculosis
 Tuberculosis is caused by a bacteria =
mycobacterium tuberculosis.
 Bacteria spread through airborne transmission
 Our body encapsulates the bacteria with a
fibrous capsule made of connective tissue to
try to protect itself, capsule is called tubercles
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Respiratory Disorders - Tuberculosis
 Symptoms: similar to flu, weight loss, tired, dry
cough.
 Treatment: Antibiotics must be taken for 6
months to 2 years – some people to stop early
– leads to antibiotic resistant strains of bacteria
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Respiratory Disorders - Bronchitis
 Bronchitis is an inflammation of the mucous
membrane of the bronchi
 Caused by viruses, bacteria, or chemical
irritation
 Symptoms: Inflammation results in the
production of excess mucus, which triggers a
deep cough
 Treatment: Depends on cause
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Respiratory Disorders - Asthma
 The smooth muscles surrounding the
bronchi spasm – causing the bronchi to
constrict, making it hard to breathe
 Causes and triggers: allergies, colds,
exercise, stress
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Respiratory Disorders - Emphysema
 Emphysema is caused by the destruction of
alveoli, usually by smoking
 Reduction in the surface area available for
gas exchange and the increased dead air
space results in shortness of breath
 Treatment - no cure, can supplement with
oxygen and drugs can dilate airways.
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Respiratory Disorders - Emphysema
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Figure 14.14
Lung Cancer
 Lung Cancer is the result of uncontrolled cell
division forms a tumor
 The smoke irritates the lining of the bronchi.
 The cilia that normally function to clear dust
and particles from the lungs are destroyed.
 Often caused by inhaled carcinogens,
including those found in tobacco smoke.
Between 85 – 90% of lung cancer is from
smoking.
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Lung Cancer
 Lung cancer is more common in men, but as
more women are smoking, the rate of lung
cancer in women is rising. Women are more at
risk
 Many compounds in the smoke are cancer
promoters, they trigger the progression of cancer
in cells.
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8-16
Effects of Smoking
 The 5-year survival rate is 13%. Smoking can
cause cancers of other parts of the respiratory
system.
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8-16
Effects of Smoking on Pregnancy
 Cigarette smoke contains CO, the fetal blood has
a higher affinity for CO than the mothers blood,
so CO builds up in the fetuses body.
 Nicotine is also passed into the fetus, stimulating
the developing nervous system.
 Men smoking can damage the DNA in their
sperm and pass genetic mutations to their
offspring.
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8-16
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Lung Cancer
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Figure 14.15
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What is the smoking policy on campus?
1. You can smoke
anywhere
2. You can smoke
anywhere outside
3. You can smoke at
designated spots
4. No smoking on campus
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Do you think smoking should be allowed on
campus?
1. Yes
2. No
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Do you smoke?
1.
2.
3.
4.
Never
Used to, but quit
Smoke, but trying to quit
Smoke
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Important Concepts
 Read Ch 15
 What is the function of the respiratory system?
 What is the location and function of the all the
parts of the respiratory system?
 What are the parts of the nasal cavity and their
functions?
 What are the parts of the larynx and their
functions?
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Important Concepts
 What cell types lines the trachea, what are
their functions, be able to discus how
smoking effects this tissue?
 Where does the exchange of gases occur in
the lungs?
 What cavity contains the lungs?
 What controls the rate of breathing?
 Be able to discuss the mechanics of
breathing?
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Important Concepts
 How is oxygen carried in the blood?
 How is carbon dioxide carried in the blood,
know all the ways, and the which is the
predominate mode? (You don’t need to know
the chemical equation of bicarbonate
formation)
 What is the diaphragm and what is its
function?
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Important Concepts
 Be able to discuss the disorders of the
respiratory system including the description,
symptoms, cause, and treatments.
 How does smoking effect pregnancy?
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Definitions
 Goblet cells, sinuses, epiglottis, surfactant,
diaphragm, intercostal muscles,
Inhalation/inspiration, exhalation/expiration
tidal volume, inspiratory reserve volume,
expiratory reserve volume, residual volume,
vital capacity, hemoglobin, oxyhemoglobin,
chemoreceptors, tubercles, antibiotic
resistant
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