Download Respiratory System

Objectives
 Observe what parts of the body are involved with
breathing
 Hypothesize why the body responds the way it does
when we breathe
How do you breathe?
AND WHY DO THOSE THINGS HAPPEN?
What does breath affect?
 Nervous system
 Given what you know
about blood flow and
breathing, how are
the circulatory and
respiratory systems
related?
Respiration
 Involves both the
respiratory and
the circulatory
systems
 Supply the body
with O2 and
dispose of CO2
Parts of the Respiratory System
 Nasal cavity
 Pharynx
 Larynx
 Trachea
 Bronchial tree
 Alveoli
Nose
 Why do you have a
nose?
 Passageway



Warm and moisten air
Filters
Resonating chamber
 Contains olfactory
receptors
Nasal Cavity
 External nares (pair of opening) nostrils
 Internal nares (internal constriction)
 Act to reduce air flow to maximize efficiency and
filtration
Pharynx
 Passageway
 3 divisions
 Nasopharynx: just air



Uvula
Oropharynx: air and food
Laryngopharynx: food and air
Larynx
 Point of divergence for
air and food


Air to trachea, food to
esophagus
Epiglottis
 Produces voice
Larynx
Trachea
 Sits atop esophagus
 Branches into bronchial
tree

Further branching
descends into lungs
Lungs
 Pleural cavities
 Lungs divided into lobes
 3 on right, 2 on left
 Surfactant reduces the surface
tension of fluid in the lungs and helps
make the small air sacs in the lungs
(alveoli) more stable. This keeps them
from collapsing when an individual
exhales. In preparation for breathing
air, fetuses begin making surfactant
while still in the womb. Babies that
are born very prematurely often lack
adequate surfactant and must receive
surfactant replacement therapy
immediately after birth in order to
breathe.
Alveoli
 End of bronchial branches
 Site of gas exchange
Oxygen transport
Can you remember??
 Describe the path air takes as it moves from outside
of your body to inside your lungs.
Breathing
 Inspire/expire
 Largely regulated by pressure
 Intrapulmonary: Pressure inside lungs
 Atmospheric: Pressure outside lungs
Breathing
video
Breathing
 Caused by changes in pressure
 Pressure moves from high concentration to low
 Inhalation:
 diaphram contracts, intercostal muscles contract
 Volume in thoracic cavity goes up, pressure goes down
 Atm. pressure> intraplural pressure= causes air to go in
 Exhalation
 Diaphram and intercostals relax
 Volume goes down, pressure goes up, air goes out
Respiratory Volume
 Spirometer- will be using in lab
 Tidal volume: normal breathing
 ~0.5 L
 Inspiratory reserve: extra you can bring in
 ~3 L
 Expiratory reserve
 ~1 L
 Residual volume
 ~1.5 L
Respiratory Capacity
 Inspiratory capacity: amount you can bring in
 Inspiratory reserve + tidal
 Functional residual capacity: amount typically in
 Expiratory reserve + residual volume
 Vital capacity: amount you can move
 Ir + tidal + er
 Total lung capacity: all volumes
OPENER DAY 2
 How do your diaphragm and intercostal muscles
behave during an inhalation versus during an
exhalation?
How Gases Move in Blood
 Pressure moves from
high to low




Pressure of CO2 in
alveoli = 40 mmHg(mm
of mercury-unit of
pressure)
Pressure in capillaries =
45 mmHg
Pressure of oxygen in
alveoli = 104 mm Hg
Pressure in capillaries =
40 mm Hg
video
Ventilation-Perfusion Coupling
Control of Breath Rate
 Depth: how much air is brought in with each
inhalation
 Rate: how frequently breaths are taken
 Affected by:




Irritant reflexes
Stretch receptors in lungs
Hypothalamic controls
Chemical controls
Influences on Breath Rate and Depth
 Main influence: raising CO2 levels
 Hyperventilation
 Exercise
 Altitude
 Acclimation
Disorders of Respiratory System
 COPD several causes
 Asthma: constrict respiratory
apparatus

Inhaler dilates
 Tuberculosis

Bacterial infection
 Pnemonia: fluid buildup in
lungs
 Lung cancer


Usually die within 1 year of diagnosis
90% smokers
OPENER



What is the main thing that controls breath rate?
What is the difference between tidal volume and
vital capacity?
What does the uvula do?