Transcript Effect Response Receptors Stimulated Factors

I.
RESPIRATION is the process of exchanging gasses
between the atmosphere and the body.
A. Moving air in and out of the lungs - Breathing /
VENTILATION
B. Exchanging gasses between the lungs and blood EXTERNAL RESPIRATION
C. Exchanging gasses between the blood and body cells INTERNAL RESPIRATION
D. Using O2 and making CO2 (waste) - Cellular respiration
II. Respiratory organs
A. Nose and nasal cavity (the hollow
space behind the nose)
1. The SEPTUM divides the nasal cavity into
right and left portions.
2. Pseudostratified epithelium (with mucous
secreting goblet cells) lines the cavity.
a. Mucous traps dust, bacteria and other particles.
b. Cilia move trapped particles along to be swallowed
where they can be killed by stomach acid.
3. Air is warmed as it passes over blood vessels in mucous
membranes.
B. Sinuses are air filled spaces that are
continuous with the nasal cavity. They are
filled with mucous membranes.
C. The PHARYNX is inferior to the nasal
cavity. It is a passageway for food
moving to the esophagus and air moving
to the lungs. IT helps to produce sounds.
D. The LARYNX is inferior to the pharynx and superior to
the trachea.
1. It is made of muscles and cartilage.
2. The EPIGLOTTIS is a flap-like structure that
prevents food from entering the trachea.
3. The vocal cords are in the larynx.
Sound is made from air being forced
between folds causing them to vibrate.
E. The TRACHEA (windpipe) extends into
the thoracic cavity and splits into the
left and right BRONCHI.
1. It is lined with mucous membranes that
trap particles and send them to the
pharynx to be swallowed.
2. 20 c-shaped pieces of hyaline cartilage
line the trachea to prevent it from
collapsing.
3. Muscle tissue between the cartilage
gives the trachea elasticity.
F. The BRONCHIAL TREE is made up of the branching
airways that lead from the trachea to the microscopic
air sacs in the lungs.
1. It branches with the right and left
primary bronchi, and after much
more branching eventually ends in
the alveolar ducts, sacs, and alveoli.
2. The alveoli have very thin walls so
that gasses can diffuse in and out
of them.
G. The LUNGS are spongy organs located in the thoracic
cavity. They are enclosed by the diaphragm.
1. PLEURAL MEMBRANES line the lungs.
2. The space between the plural
membranes and the other body
organs is called the PLEURAL
CAVITY. It is lined with mucous
membranes that lubricate the lungs
to reduce friction from breathing.
III. Mechanisms for breathing
A.
INSPIRATION (inhalation) occurs because of air
pressure differences between the environment and the
lungs.
1. Air pressure and volume are inversely related.
Pressure
Volume
Pressure
Volume
2. During an inhale, the diaphragm and
INTERCOSTAL MUSCLES ( between
ribs) contract and expand the chest
cavity, lowering the pressure below
the outside air pressure causing air
to rush into the lungs.
3. During an exhale, the diaphragm and
intercostal muscles relax and the
chest cavity gets smaller. This
increases the pressure in the chest
cavity above the outside air
pressure. Air from the lungs (high
pressure) flows out of the airways to
the outside air (low pressure).
IV. Respiratory volume and capacities (see pages 749-750)
V. Non-respiratory air movements
Air
Movement
Mechanism
Function
Coughing
Deep breath is taken, glottis is closed, and air
is forced against the closure; suddenly the
glottis is opened and a blast of air passes
upward
Sneezing
Same as coughing, except air moving upward is
Clears upper
directed into the nasal cavity by depressing the respiratory
uvula
passages
Laughing
Deep breath is released in a series of
expirations
Expresses
happiness
Same as laughing
Expresses
sadness
Crying
Clears lower
respiratory
passages
Air
Movement
Hiccuping
Mechanism
Function
Diaphragm contracts
spasmodically while glottis is
closed
No useful function known
Yawning
Deep breath is taken
Ventilates a larger proportion
of the alveoli and aids
oxygenation of the blood
Speech
Air is forced through the
larynx, causing vocal cords to
vibrate; words are formed by
lips, tongue, and soft palate
Vocal communication
VI. Breathing is controlled by the respiratory
center in the brainstem
VII. Factors that affect breathing
Factors
Receptors
Stimulated
Response
Effect
Stretch of
tissues
Stretch
receptors in
visceral pleura,
bronchioles, and
alveioli
Inhibits
inspiration
Prevents over
inflation of the
lungs during
forceful
breathing
Low blood
pressure (O2)
Chemoreceptors
in carotid and
aortic bodies
Increases
alveolar
ventilation
Increases blood
oxygen
concentration
High blood
pressure (CO2)
Chemosensitive
areas of the
respiratory
center
Increases
alveolar
ventilation
Decreases blood
carbon dioxide
concentration
VII.Alveolar gas exchanges
A. Alveoli are microscopic air
sacs clustered at the ends
of the distal ends of
respiratory tubes. They are
surrounded by very thin
membranes in contact with
blood vessels.
B. Gasses diffuse from the
alveoli to the blood vessels.