Transcript Figure 13.5a

13
PART A
The Respiratory
System
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Organs of the Respiratory system
 Nose
 Pharynx
 Larynx
 Trachea
 Bronchi
 Lungs –
alveoli
Figure 13.1
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Function of the Respiratory System
 Oversees gas exchanges between the blood
and external environment
 Exchange of gasses takes place within the
lungs in the alveoli
 Passageways to the lungs purify, warm, and
humidify the incoming air
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The Nose
 The only externally visible part of the
respiratory system
 Air enters the nose through the external nares
(nostrils)
 The interior of the nose consists of a nasal
cavity divided by a nasal septum
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Upper Respiratory Tract
Figure 13.2
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1. Nasal Cavity
9. Left Lung
2. Pharynx
10. Diaphragm
3. Epiglottis
11. True Ribs
4. Larynx
12. Esophagus
5. Trachea
6. Right Bronchus
7. Left Bronchus
8. Right Lung
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http://www.student.loretto.org/anatomyphys/Ke
y%20diagram--Respiratory%20System.htm
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Trachea
Main
Bronchus
Lobar
Bronchus
Segmental
bronchi
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capilaries
Bronchi
Aveolus
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Alveolar
sac
Anatomy of the Nasal Cavity
 Olfactory receptors are located in the mucosa
on the superior surface
 The rest of the cavity is lined with respiratory
mucosa
 Moistens air
 Traps incoming foreign particles
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Anatomy of the Nasal Cavity
 Lateral walls have projections called conchae
 Increases surface area
 Increases air turbulence within the nasal
cavity
 The nasal cavity is separated from the oral
cavity by the palate
 Anterior hard palate (bone)
 Posterior soft palate (muscle)
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Paranasal Sinuses
 Cavities within bones surrounding the nasal
cavity
 Frontal bone
 Sphenoid bone
 Ethmoid bone
 Maxillary bone
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Paranasal Sinuses
 Function of the sinuses
 Lighten the skull
 Act as resonance chambers for speech
 Produce mucus that drains into the nasal
cavity
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Pharynx (Throat)
 Muscular passage from nasal cavity to larynx
 Three regions of the pharynx (throat)
 Nasopharynx – superior region behind
nasal cavity
 Oropharynx – middle region behind mouth
 Laryngopharynx – inferior region attached
to larynx
 The oropharynx and laryngopharynx are
common passageways for air and food
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Structures of the Pharynx
 Auditory tubes enter the nasopharynx
 Tonsils of the pharynx
 Pharyngeal tonsil (adenoids) in the nasopharynx
 Palatine tonsils in the oropharynx
 Lingual tonsils at the base of the tongue
 Tonsils and adenoids are on the body’s first line
of defense—our immune system. They “sample”
bacteria and viruses that enter the body through
the mouth or nose at the risk of their own
infection.
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Quiz
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12
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15
13
14
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Larynx (Voice Box)
 Routes air and food into proper channels
 Plays a role in speech
 Made of eight rigid hyaline cartilages and a
spoon-shaped flap of elastic cartilage (glottis)
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Structures of the Larynx
 Thyroid cartilage
 Largest hyaline cartilage
 Protrudes anteriorly (Adam’s apple)
 Epiglottis
 Superior opening of the larynx
 Routes food to esophagus and air toward
the larynx
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Structures of the Larynx
 Vocal cords (vocal folds)
 Vibrate with expelled air to create sound
(speech)
 Glottis – opening between vocal cords
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Trachea (Windpipe)
 Connects larynx with bronchi
 Lined with ciliated mucosa
 Mucus is produced by goblet cells
 Beat continuously in the opposite direction
of incoming air (WHY?)
 Expel mucus loaded with dust and other
debris away from lungs
 Walls are reinforced with C-shaped hyaline
cartilage
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Primary Bronchus
 Formed by division of the trachea
 Right bronchus is wider, shorter,
and straighter than left
 Bronchi subdivide into smaller
and smaller branches
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Lungs
 Occupy most of the thoracic cavity
 Apex -base rests on the diaphragm
(inferior portion)
 Each lung is divided into lobes by fissures
 Left lung – two lobes
 Right lung – three lobes
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Lungs
Figure 13.4b
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Coverings of the Lungs
 Pulmonary (visceral) pleura covers the lung
surface
 Parietal pleura lines the walls of the thoracic
cavity
 Pleural fluid fills the area between layers of
pleura to allow gliding
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Bronchioles
 Bronchi get
smaller as
they branch
off
Figure 13.5a
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Bronchi
 All but the
smallest
branches
have
reinforcing
cartilage
Figure 13.5a
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Bronchi
 Terminal
bronchi end in
alveoli
Figure 13.5a
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HW
 What is the purpose of pleural fluid?
 Why do cilia move the opposite direction of
air?
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Respiratory Zone
 Structures
 Respiratory bronchi
 Alveolar duct
 Alveoli
 Site of gas exchange
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Alveoli
 Structure of alveoli
 Alveolar duct
 Alveolar sac
 Alveolus
 Gas exchange takes place within the alveoli
in the respiratory membrane
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13
The Human Lung
PART A
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Energy Needs
 The body consists of trillions of “engines”
 Each cells needs glucose and oxygen
 The lungs serve as the supplier of oxygen
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Energy Byproducts
 In the body glucose is the main source of
energy
 Carbon Dioxide is the main byproduct and is
released from the blood by the lungs
 C02 drives the breathing rate – not oxygen
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Other Functions of the Lungs
 Exchange of 02 and C02
 Keeps the bodies pH (acid) constant
 Moisturizes the air
 We can “see” our breath in the winter
 Play a role in heat exchange
 Voice production (power of 1mW)
 Air for yawning sighing, laughing, sniffing
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Breathing
 We breath about 6 liters of air per minute
 This is about the same as the heart pumps
 Men breath about 12/minute
 Women breath about 18/minute
 Infants breath abut 60/minute
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What We Breath In and Out
INSPIRATION
EXPIRATION
80%
Nitrogen
80%
20%
Oxygen
16%
0%
Carbon Dioxide
4%
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 The lungs have a large
surface area
 The convoluted
surfaces have a surface
area of 80m2
 This is at least ½ the
size of a tennis court
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 The lungs have a greater
exposure to the
environment than any
other part of the body –
including the skin.
 The air we breath
contains dust, smoke,
bacteria, noxious gases
 All come in contact with
the blood.
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 The trachea divides in
the right and left stem
bronchus
 Each bronchus then
divides 15 more times
 The terminal
bronchioles supply air
to millions of small sacs
called alveoli
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Alveoli
 At birth the lungs have
30 million
 At age 8 the number is
about 300 million
 That is about
100,000/day increase
 They stay pretty
constant after that
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sci.life.reg.exercise/
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Alveoli
 They act as tiny
interconnected bubbles.
 They are 0.2 mm in
diameter
 The walls are 0.4
micrometers thick
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 Each alveolus is
surrounded by blood so
that 02 and C02 can
exchange through
diffusion.
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 The airways must be
able to remove
particles.
 The body does this in
two ways
 1. Coughing removes
large particles
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 2. Small particles are
carried upward by
millions of small hairs
called cilia.
 They vibrate about
1000/minute
 Mucous moves 1 – 2
cm/minute
 It takes 30 minutes to be
cleared.
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Kartagener's Syndrome
 This is a lung disease
that occurs when cilia
are unable to move
 Individuals have
abnormal or absent
ciliary motion.
 Kartagener's Syndrome
is also called Immotile
Cilia Syndrome
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Respiratory Membrane (Air-Blood Barrier)
 Thin squamous epithelial layer lining alveolar
walls
 Pulmonary capillaries cover external surfaces
of alveoli
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Respiratory Membrane (Air-Blood Barrier)
Figure 13.6
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Gas Exchange
 Gas crosses the respiratory membrane by
diffusion
 Oxygen enters the blood
 Carbon dioxide enters the alveoli
 Macrophages add protection
 Surfactant coats gas-exposed alveolar
surfaces
 helps to prevent the alveoli from
collapsing
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Events of Respiration
 Pulmonary ventilation – moving air in and out
of the lungs
 External respiration – gas exchange between
pulmonary blood and alveoli
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Mechanics of Breathing (Pulmonary
Ventilation)
 Completely mechanical process
 Depends on volume changes in the thoracic
cavity
 Volume changes lead to pressure changes,
which lead to the flow of gases to equalize
pressure
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Inspiration
 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
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Inspiration
Figure 13.7a
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HW
1. Where does gas exchange actually take
place in the lungs?
2. How do we do inspiration and expiration?
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Expiration
 Largely a passive process which depends on
natural lung elasticity
 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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Expiration
Figure 13.7b
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Nonrespiratory Air Movements
 Can be caused by reflexes or voluntary
actions
 Examples
 Cough and sneeze – clears lungs of debris
 Laughing
 Crying
 Yawn
 Hiccup
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Respiratory Volumes and Capacities
 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
 Residual volume of air – after exhalation, about
1200 ml of air remains in the lungs
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Respiratory Volumes and Capacities
 Inspiratory reserve volume (IRV)
 Amount of air that can be taken in forcibly
over the tidal volume
 Usually between 2100 and 3200 ml
 Expiratory reserve volume (ERV)
 Amount of air that can be forcibly exhaled
 Approximately 1200 ml
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Respiratory Volumes and Capacities
 Residual volume
 Air remaining in lung after expiration
 About 1200 ml
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Respiratory Volumes and Capacities
 Vital capacity
 The total amount of exchangeable air
 Vital capacity = TV + IRV + ERV
 Dead space volume
 Air that remains in conducting zone and
never reaches alveoli
 About 150 ml
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Respiratory Volumes and Capacities
 Functional volume
 Air that actually reaches the respiratory
zone
 Usually about 350 ml
 Respiratory capacities are measured with a
spirometer
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Respiratory Capacities
Figure 13.9
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HW
 Describe the different types of lung volumes.
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