Download Respiratory System Notes Slides

7/28/2014
I. Overview
Respiratory System
Anatomy & Physiology
Chapter 14
A. Function:
Brings about
the exchange
of oxygen and
carbon dioxide
between the
blood, the air,
and tissues
C. Respiratory tract
Pathway of air from
nose to lungs
Air in the respiratory
tract are:
B. Organs
Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs – alveoli
– Cleansed – by hairs,
cilia, and mucus
– Warmed – by heat
from the blood
vessels
– Moistened – by the
wet surfaces in the
passageway
Review
Necessary to keep
lung tissue healthy
II. Structure
A. Upper Respiratory Tract
What
happens to air as it travels
through the respiratory tract to
ensure that the lung tissues remain
healthy?
– Nasal cavities, pharynx, larynx
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1. Nasal Cavity
Description: Hollow canals separated by a
septum of bone and cartilage
Function: Filter, warm, and moisten the air
Paranasal Sinuses – Cavities within bones
surrounding the nasal cavity
– Increases surface area
– Increases air turbulence within the nasal cavity
– Function of the sinuses
Lighten
the skull
as resonance chambers for speech
Produce mucus that drains into the nasal cavity
Act
Contains lateral projections called conchae
The nasal cavity is separated from the oral
cavity by the palate
– Anterior hard palate (bone)
– Posterior soft palate (muscle)
Mucous membrane lines nasal cavity
– Cilia moves mucous and trapped particles to
the pharynx
Hard Palate
Soft
Palate
2. Pharynx – Throat
– Nasopharynx – superior
region, passageway for air
– Oropharynx – where oral
cavity joins pharynx,
passageway for food and
air
– Laryngopharynx – inferior
region that opens to
larynx
Description:
funnel-shaped
passageway
between the
nasal cavity
and larynx
Function:
Connects nasal
and oral
cavities to the
larynx
Three regions of the
pharynx
Tonsils – located in
oropharynx
– A lymphatic tissue that
protects against inhaled
pathogens
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3. Larynx
Description: Also called
the voice box, contains
the vocal cords
Function: Produces
sound
Vocal cords are elastic
tissues that vibrate
producing sound as air
travels through
Epiglottis - flap of
tissue that sits at
the base of the
tongue
– prevents food from
entering the trachea,
or windpipe, during
swallowing
– The opening or slit in the
vocal cords is called the
glottis
Review
B. Lower Respiratory Tract
– Trachea, bronchi, bronchioles, lungs,
alveoli
List
the organs (pathway) air travels
through in the upper respiratory
tract.
4. Trachea
Description:
known as the
windpipe, flexible
tube that
connects larynx to
bronchi
Function: directs
air to bronchi
Held
open by C-shaped hyaline
cartilage
Trachea is lined with pseudostratified
ciliated columnar epithelial cells
– Cilia sweeps mucus loaded with dust and
other debris away from lungs
Cilia
Goblet
cells
Pseudostratified
epithelial
Basement
membrane
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Vocabulary Review
Breakdown the words “pseudostratified
ciliated columnar epithelial” to understand
the meaning.
“pseudo” – fake
“stratified” – layers
“ciliated” – with hair like projections
“columnar” – cells that are taller than wider
5. Bronchi
Description:
Left
and right
branched tubes of
the trachea
Function:
passageway of air
to lungs
6. Bronchioles
Bronchi
enters the
right and left lungs
– Bronchi subdivide into
smaller and smaller
branches called
bronchioles
Right
bronchus is
wider, shorter,
and straighter than
left
7. Lungs
Description:
paired, coneshaped organ
that occupy the
thoracic cavity
Function:
contains
alveolus where
gas exchange
occurs
Description:
Smallest
branches of the
bronchi
Function:
Bronchioles
lead to the
alveoli
Apex
(superior
portion) is near
the clavicle
Base (inferior
portion) rests on
the diaphragm
Each lung is
divided into lobes
by fissures
– Left lung – two
lobes
– Right lung – three
lobes
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8. Alveoli
Coverings
of the lungs
– Visceral pleura covers the lung
– Parietal pleura lines the walls of the
thoracic cavity
– Pleural fluid fills the area between layers
of pleura to allow gliding
membrane – extremely
thin membrane that aids in the rapid
exchange of gases
Description:
Structure made up
of simple squamous
epithelium
surrounded by
blood capillaries
Function: Exchange
of gas
Respiratory
Gas
crosses the respiratory
membrane by diffusion
– Oxygen enters the blood
– Carbon dioxide enters the alveoli
Macrophages
add protection
in alveoli prevents the
lung from closing or collapsing
Surfactant
Review
List
the organs (pathway) air travels
in the lower respiratory tract.
Review
What
gases are exchanged in the
respiratory membrane?
How
are gases moved or transported
across the membrane?
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A. External Respiration
III. Gas Exchange and Transport
Exchange of gases
between air and blood
in the lungs
Blood entering the
lungs is oxygen-poor
and carbon dioxide-rich
Oxygen movement into
the blood
Respiration
–
process of
exchanging gases
between the
atmosphere and
body cells
Carbon dioxide
movement out of the
blood
– Blood returning from
tissues has higher
concentrations of carbon
dioxide than air in the
alveoli
– Pulmonary capillary
blood gives up carbon
dioxide
Blood leaving the
lungs is oxygen-rich
and carbon dioxidepoor
– The alveoli always has
more oxygen than the
blood
– Oxygen moves by
diffusion from an area of
high concentration to an
area of low concentration
B. Internal Respiration
Exchange
of gases
between blood and
body cells
An opposite
reaction to what
occurs in the lungs
– Carbon dioxide
diffuses out of
tissue to blood
– Oxygen diffuses
from blood into
tissue
C. Gas Transport
Oxygen
transport in the blood
– Inside red blood cells attached to
hemoglobin (oxyhemoglobin [HbO2])
– A small amount is dissolved in the
plasma
Carbon
dioxide transport in the blood
– Most is transported in the plasma as
bicarbonate ion (HCO3–)
– A small amount is carried inside red
blood cells on hemoglobin, but at
different binding sites than those of
oxygen
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Summary
Draw
a flow map showing the
pathway air travels through the
respiratory system. Underneath
each structure, write down the
function.
Ex.
IV. Mechanism of Breathing
Ventilation
– manner in which air
enters and exits the lungs
Two phases
– Inspiration – flow of air into lung
– Expiration – air leaving lung
A. Inspiration
Active
phase of ventilation
Diaphragm and intercostal muscles
contract
The size of the thoracic cavity
increases
External air is pulled into the lungs
due to an increase in intrapulmonary
volume
B. Expiration
Largely
a passive process which
depends on natural lung elasticity
Diaphragm and intercostal muscles
relax
As muscles relax, air is pushed out of
the lungs
Forced expiration can occur mostly
by contracting internal intercostal
muscles to depress the rib cage
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C. Nonrespiratory Air Movements
What
Happens When you Breath?
Can
be caused by reflexes or
voluntary actions
Examples
– Cough and sneeze – clears lungs of
debris
– Laughing
– Crying
– Yawn
– Hiccup
D. Ventilation Control
Normal
breathing rate is 12-20
ventilation per minute
Controlled by the respiratory center
in the medulla oblongata (brain)
Factors that influence ventilation
– Nervous input
– Chemical input
1.
Nervous input
– Intercostal and
phrenic nerve
stimulate muscles
to contract for
inspiration
– Lack of
stimulation
results in
expiration
E. Respiratory Volumes
2.
Chemical input
– Level of carbon dioxide in the blood is
the main regulatory chemical for
respiration
– Increased carbon dioxide increases
respiration
Normal
breathing moves about 500
ml of air with each breath (Tidal
Volume [TV])
Many factors that affect respiratory
capacity
– A person’s size
– Sex
– Age
– Physical condition
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Inspiratory
reserve volume (IRV)
– Amount of air that can be taken in
forcibly over the tidal volume
– Usually between 2100 and 3200 ml
Expiratory
Residual volume
– Air remaining in lung after expiration
– About 1200 ml
Vital capacity
– The total amount of exchangeable air
– Vital capacity = TV + IRV + ERV
reserve volume (ERV)
– Amount of air that can be forcibly
exhaled
– Approximately 1200 ml
Functional
Dead space volume
– Air that remains in conducting zone and never
reaches alveoli
– About 150 ml
volume
– Air that actually reaches the respiratory
zone
– Usually about 350 ml
Respiratory
capacities are measured
with a spirometer
V. Respiratory Disorders
B. Laryngitis – infection of
larynx
C. Chronic Obstructive Pulmonary Disease
(COPD)
– Term used to describe several progressive lung
diseases
– Major causes of death and disability in the United
States
– Example: chronic bronchitis, emphysema, asthma
A. Tonsillitis – occurs
when tonsils become
inflamed and enlarged
– Can make breathing difficult
– Tonsils are the first line of
defense against pathogens
that enter the pharynx
1. Chronic Bronchitis
– Airway becomes inflamed and fills with mucus
– Loss of cilia and normal cleansing action
– Caused by smoking cigars, cigarettes, and
some pollutants
– Lead to inability to talk
audibly
– Disappears with treatment
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2.
Emphysema
– Chronic and
incurable disorder
where the alveoli
bursts and fuse into
larger air spaces
– Reduces surface
area for gas
exchange
– Caused by prolong
cigarette smoking
3. Asthma
– Disease of the bronchi and bronchioles marked
by wheezing and breathlessness
– Airways are sensitive to irritants (pollen,
animal dander, dust, etc)
– Causes muscle in the bronchioles to spasm and
may even cause them to become inflamed
– Treated with inhalers that stop the spasms or
reduce the inflammation
D. Lung Cancer
Caused
by smoking cigarettes &
second hand smoke
Lung cancer begins with the
thickening and callusing of the
bronchi
Atypical cells appear in tissue, tumor
forms
Cells break loose and spread to other
organs (metastasis)
Tumor
can grow until it blocks
bronchi, cutting off air supply, lung
collapses
Treatments:
– Pneumonectomy – remove a lobe or a
whole lung
– Chemotherapy
– Radiation
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