Download The Respiratory System

Environmental Exchange
Fundamentals of
Anatomy & Physiology
The Respiratory System
What are the
primary functions of
the respiratory system?
Oxygen
• Is obtained from the air by diffusion
across delicate _______ surfaces of
lungs
• Is carried to cells by the cardiovascular
system which also returns _____ _____
to the lungs
5 Functions of the
Respiratory System
1. Provides extensive gas exchange
_____ ____ between air and
circulating blood
2. Moves air to and from exchange
surfaces of lungs
5 Functions of the
Respiratory System
3. ______ respiratory surfaces from
outside environment
4. ______ sounds-speaking, singing
5. Participates in ________ sense
Components of the Respiratory System
Figure 23–1
Organization of the
Respiratory System
• The respiratory system is divided into
the _______ respiratory system, above
the larynx, and the _______ respiratory
system, from the larynx down
The Respiratory Tract
• Consists of a ________ portion:
– from nasal cavity to terminal bronchioles
• Consists of a ___________ portion:
– the respiratory bronchioles and alveoli Are air-filled pockets within the lungs
• where all gas exchange takes place
The Respiratory Epithelium
• For gases to exchange efficiently:
– alveoli walls must be very thin (< 1 µm)
– surface area must be very great (about __
times the surface area of the body)
The Respiratory Mucosa
• Consists of:
– an ________ layer
– an _______ layer
• Lines conducting portion of respiratory
system
Alveolar sac
Alveoli
Figure 23–2
The Lamina Propria
• Underlies areolar tissue
• In the upper respiratory system, trachea, and
bronchi:
– contains _______ glands that secrete onto
epithelial surface
• In the conducting portion of lower respiratory
system:
– contains _____ muscle cells that encircle lumen of
bronchioles
The Respiratory Epithelium
Figure 23–2
How are delicate
respiratory exchange surfaces
protected from pathogens,
debris, and other hazards?
The Respiratory Defense System
• Consists of a series of _____
mechanisms
• Removes particles and _________
Components of the Respiratory
Defense System (1 of 2)
• _______ cells and mucous glands:
– produce mucus that bathes exposed
surfaces
• Cilia:
– _______ debris _______ in mucus toward
the pharynx (mucus escalator)
Components of the Respiratory
Defense System (2 of 2)
• _________ in nasal cavity removes
large particles
• Alveolar _________ engulf small
particles that reach lungs
What are the organs of the
upper respiratory system and
their functions?
The Upper Respiratory System
Figure 23–3
The Nose
• Air enters the respiratory system:
– through nostrils or ______ nares
– into nasal _________
• Nasal hairs:
– are in nasal vestibule
– are the first particle filtration system
The Nasal Cavity
• The nasal ________:
– divides nasal cavity into left and right
• Mucous secretions from paranasal sinus
and tears:
– clean and moisten the nasal cavity
• Superior portion of nasal cavity is the
_________ region:
– provides sense of smell
• From vestibule
to internal
nares:
– through
superior,
middle, and
inferior
meatuses
Air Flow
Meatuses
• Constricted
passageways that
produce air
turbulence:
– _____ and
_______ incoming
air
– ______ particles
The Palates
• Hard palate:
– forms ______ of
nasal cavity
– separates nasal
and oral cavities
• Soft palate:
– extends _______
to hard palate
– divides superior
nasopharynx from
lower pharynx
The Nasal Mucosa
• Warm and
humidify inhaled
air for arrival at
lower respiratory
organs
• Breathing
through mouth
bypasses this
important step
The Pharynx
• A chamber shared
by digestive and
respiratory
systems
• Extends from
internal nares to
entrances to
larynx and
esophagus
Divisions of the Pharynx
• ____pharynx
• ____pharynx
• ______pharynx
The Nasopharynx
• ______ portion of
the pharynx
• Contains
pharyngeal tonsils
and openings to
left and right
auditory tubes
The Oropharynx
• ______ portion of
the pharynx
• Communicates
with oral ______
The
Laryngopharynx
• _______ portion
of the pharynx
• Extends from
hyoid bone to
entrance to
larynx and
esophagus
What is the structure
of the larynx and its
role in normal breathing
and production of sound?
Anatomy of the Larynx
Figure 23–4
Cartilages of the Larynx
• 3 large, unpaired
cartilages form the
larynx:
– the ______ cartilage
– the ______ cartilage
– the _______
The Thyroid Cartilage
• Also called the Adam’s
apple
• Is a _______ cartilage
• Forms anterior and
lateral walls of larynx
• Ligaments attach to
_____ bone, epiglottis,
and laryngeal
cartilages
The Cricoid
Cartilage
• Is a ______
cartilage
• Form posterior
portion of larynx
• Ligaments attach
to first tracheal
cartilage
• Articulates with
arytenoid
cartilages
The Epiglottis
• Composed of
_______
cartilage
• Ligaments
attach to
______
cartilage and
hyoid bone
Cartilage Functions
• Prevents entry of food and liquids into
respiratory tract
– During __________:
– the larynx is elevated
– the epiglottis folds back over glottis
• Thyroid and cricoid cartilages support and
protect:
– the _______
– the entrance to trachea
The Glottis
Figure 23–5
Sound Production
• Air passing through glottis:
– _______ vocal folds
– produces sound waves
Sound Variation
• Sound is varied by:
– tension on vocal folds
– voluntary muscles (position arytenoid cartilage
relative to thyroid cartilage)
What is the structure of
airways outside the lungs?
Anatomy of the Trachea
Figure 23–6
The Trachea
• Also called the
_________
• Extends from
the cricoid
cartilage to the
internal ridge
– where it
branches into
right and left
pulmonary
_________
The Tracheal Cartilages
• ___–20 tracheal cartilages:
– strengthen and protect airway
– discontinuous where trachea contacts
esophagus
• Ends of each tracheal cartilage are
connected by:
– an elastic ligament and __________
muscle
The Primary Bronchi
• Right and left primary bronchi:
– separated by an internal ridge (the ______)
The Right Primary Bronchus
• Is ______ in diameter than the left
• Descends at a _________ angle
The Lungs
• Left and right
lungs:
– are in left and
right _______
cavities
• The base:
– inferior portion of
each lung rests on
superior surface
of ________
The Right Lung
• Has _ lobes:
– superior,
middle, and
______
– separated by
horizontal and
oblique fissures
The Left Lung
• Has _ lobes:
– superior and
inferior
– are separated
by an oblique
fissure
Relationship between Lungs and Heart
Figure 23–8
Lung Shape
• Right lung:
– is wider
– is displaced upward by _____
• Left lung:
– is _______
– is displaced leftward by the heart forming
the cardiac notch
The Bronchial Tree
• Is formed by the primary bronchi and their
branches
Extrapulmonary Bronchi
• The left and right bronchi branches _____ the
lungs
Intrapulmonary Bronchi
• Branches within the lungs
A Primary Bronchus
• Branches to form secondary bronchi (lobar
bronchi)
• 1 secondary bronchus goes to each lobe
Bronchi and Lobules
Figure 23–9
Secondary Bronchi
• Branch to form
______ bronchi, also
called the
segmental bronchi
• Each segmental
bronchus:
– supplies air to a
single
bronchopulmonary
segment
Bronchial
Structure
• The walls of
primary, secondary,
and tertiary
bronchi:
– contain
progressively less
________ and ____
smooth muscle
– increasing muscular
effects on airway
constriction and
resistance
Bronchitis
• _____________ of bronchial walls:
– causes constriction and breathing
difficulty
The Bronchioles
Figure 23–10
Bronchiole Structure
• Bronchioles:
– have no ___________
– are dominated by smooth muscle
Autonomic Control
• Regulates smooth muscle:
– controls diameter of bronchioles
– controls airflow and resistance in lungs
Asthma
• Excessive stimulation and bronchoconstriction
• Stimulation severely restricts airflow
The Bronchioles
• Each tertiary
bronchus branches
into multiple
bronchioles
• Bronchioles
branch into
terminal
bronchioles:
– 1 tertiary
bronchus forms
about 6500
terminal
bronchioles
Alveolar Organization
Figure 23–11
Alveolar
Organization
• Respiratory
bronchioles are
connected to
alveoli along
alveolar ducts
• Alveolar ducts
end at alveolar
sacs:
– common
chambers
connected to
many individual
alveoli
An Alveolus
• Has an
extensive
network of
capillaries
• Is
surrounded
by ______
fibers
Alveolar
Epithelium
• Consists of simple
squamous
epithelium
• Consists of thin,
delicate Type I cells
• Patrolled by
alveolar
__________, also
called dust cells
• Contains septal cells
(Type II cells) that
produce __________
Surfactant
• Is an _____
secretion
• Contains
phospholipids and
proteins
• Coats alveolar
surfaces and
_______ surface
tension
• Helps diffusion of
O2
Inflammation of Lobules
• Also called pneumonia:
– causes fluid to leak into alveoli
– compromises function of respiratory
membrane
Pleural Cavities and Pleural Membranes
Figure 23–8
Respiration
• Refers to 2 integrated processes:
– external respiration
– internal respiration
External Respiration
• Includes all processes involved in exchanging
O2 and CO2 with the environment
Internal Respiration
• Also called cellular respiration
• Involves the uptake of O2 and production of
CO2 within individual cells
3 Processes of
External Respiration
1. Pulmonary ventilation (breathing)
2. Gas diffusion:
–
across membranes and capillaries
3. Transport of O2 and CO2:
–
–
between alveolar capillaries
between capillary beds in other tissues
Gas Pressure and Volume
As volume decreases, pressure
increases
Figure 23–13
Mechanisms of Pulmonary Ventilation
Figure 23–14
Respiration
• Causes volume changes that create
changes in pressure
• Volume of thoracic cavity changes:
– with expansion or contraction of
diaphragm or rib cage
The Respiratory Muscles
Figure 23–16a, b
The Respiratory Muscles
Figure 23–16c, d
3 Muscle Groups of Inhalation
Diaphragm is the main one.
Abdominal muscle system used in
exhaling
Respiratory Performance and Age
Figure 23–28
3 Effects of Aging on the Respiratory System
1. Elastic tissues deteriorate:
–
–
reducing lung compliance
lowering vital capacity
2. Arthritic changes:
–
–
restrict chest movements
limit respiratory minute volume
3. Emphysema:
–
–
affects individuals over age 50
depending on exposure to respiratory
irritants (e.g., cigarette smoke)