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RESPIRATORY
SYSTEM
By: Ellie Conzatti, Kelsey Betteridge, and Michele Short
Functions
• Cellular Respiration (obtaining oxygen and removing carbon
dioxide)
• Removing particles from the air
• Transport air to and from lungs
• Control temperature and moisture content of air
• Produce vocal sounds
• Help regulate blood pH and sense of smell
Structures of the Respiratory System
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Nose
Nasal cavity
Hard palate
Nostril
Oral cavity
Larynx
Bronchus
Right & left lung
Soft palate
Pharynx
Epiglottis
Esophagus
Trachea
Organs of the Respiratory System
Upper Respiratory Tract
• Nose, Nasal cavity, paranasal sinuses, and pharynx
Lower Respiratory Tract
• Larynx, trachea, bronchial tree, and lungs
Nose
• Bone and cartilage support the nose
• There are two nostrils which air can
enter and leave the nasal cavity
• Hairs within the nostrils prevent
large particles from entering
Nasal Cavity
• Hollow space behind the nose
• The nasal septum divides the right and left portions of the nasal cavity
• Nasal concha are bones that curl away from the lateral walls of the
nasal cavity on each side forming passageways within the cavity
• Mucous membrane has…
* pseudo stratified ciliated epithelium
* mucus-secreting goblet cells
* network of blood vessels
* mucus lining
* sticky mucus
Paranasal sinuses
• Hollow spaces in certain skull bones
which are located in the:
• Maxillary
• Frontal
• Ethmoid
• Sphenoid Bones
• Reduces weight of skull
• Serves as resonant chambers
• Affects the sound of the voice
Pharynx
• Chamber behind nasal cavity,
oral cavity, and larynx
• Passageway for air moving
from nasal
cavity to larynx
• Food moves from oral cavity to
esophagus
Larynx
• Passageway for air and prevents foreign objects from entering
trachea
• The glotis is the opening between the vocal cords that closes
during swallowing. During breathing , they are relaxed and it
looks like a triangular slit.
• A framework of muscles and cartilages compose the larynx
• Thyroid (“Adam’s apple”)
• Cricoid
• Epiglottic cartilages
Larynx (cont.)
• Contains the epiglottis, a
flap-like structure that closes
downward to cover the
opening into the larynx
during swallowing. This
prevents food and liquids
from entering the air
passages.
Trachea (Windpipe)
• Flexible tube that connects the larynx with the
bronchial tree by splitting into left and right
bronchi.
• Passageway for air
• Air is being filtered by a ciliated mucous
membrane covering the wall. Filtered air is
moved upward into the pharynx where the
mucus is swallowed.
• Consists of about 20 C-shaped hyaline cartilage
pieces which are filled with smooth muscle and
connective tissue between the ends.
Bronchial Tree
• Branched tubes that lead from the trachea to the lungs
• Has a mucous lining that continues to filter incoming air
• Divides into the right and left primary bronchi and then each one
further divides into secondary bronchi.
• Bronchioles are among these smaller tubes and finally break into
small tubes called alveolar ducts, which lead to alveolar sacs.
Alveolar sacs are surrounded by alveoli.
Bronchial Tree (cont.)
The alveoli’s large surface area of epithelial cells allow gases
to be exchanged. Oxygen enters nearby capillaries and
carbon dioxide enters the alveoli from the blood through these
walls.
Lungs
• Soft, cone-shaped organs that occupy a large portion of the thoracic
cavity
• Contains air passages, alveoli, blood vessels, connective tissues, lymphatic
vessels, and nerves of the lower respiratory tract.
• The visceral pleura, which is a serous membrane, attaches to each lung
surface. It folds back to become the parietal pleura, a part of the
mediastinum, a layer of the inner wall of the thoracic cavity. The potential
space between these two layers is the pleural cavity.
• The right lung is larger than the left
• The right is divided into three parts
• The left is divided into two parts
Breathing Mechanism
• The movement of air coming from the outside of the body and
going into and out the bronchial tree and alveoli
• Inspiration- inhaling
• Expiration- exhaling
Inspiration
• When the pressure in the lungs and alveoli decreases, the
pressure pushes outside the air into the pathways
• This is normal inspiration. While the external intercostal muscles
between the ribs are contracting, this is what raises the ribs and
the sternum, causing the thoracic cavity to enlarge
• When a person needs to take a bigger and deeper breath, the
diaphragm and external intercostal muscles contracts even more
to help with the breathing
Expiration
• To get back to the normal shape, the abdominal organs bounce
back pushing the diaphragm up again
• When a person needs to exhale more than normal, the posterior
internal intercostal muscles are contracting
• This causes the ribs and sternum down and in which increases the
pressure inside the lungs
Respiratory Center
• Respiratory muscles are voluntary whereas normal breathing is involuntary
• The respiratory center controls both inspiration and expiration
• It is a group of neurons
• The neurons are scattered throughout the medulla oblongata and the pons
• The dorsal respiratory group controls the rhythm of inspiration
• This impulses the diaphragm and the other inspiratory to contract
• It begins weak, strengthens for two seconds and decreases again
• The muscles that contract, increase the air that enters the lungs
• The ventral respiratory group is quiet when the breathing is normal, but when
more force is needed, this impulses an increase in the inspiratory movement.
Respiratory Membrane
• The aveolus consists of inner
lining of simple squamous
epithelium and capillaries as
well
• Thin basement membranes
separate these layers and in the
spaces between, the elastic
and collagenous fibers support
the alveolar wall
• Composed of the alveolar wall
and the capillary wall through
which air exchanges gases
Air and Blood Exchange Gases
Across Alveoli To Capillaries
• Diffusion occurs from areas of higher pressure
to areas of lower pressure.
• Ordinary air consists of 78% nitrogen, 21%
oxygen, and .04% carbon dioxide.
• The pressure each gas gives is the partial
pressure.
• Gas concentration is proportional to its
partial pressure
• PCO2 in capillaries is 45 mm Hg while in
alveolar air it is 40 mm Hg
• PO2 in blood is 40 mm Hg while in alveolar
air it is 104 mm Hg
Gas Transport By Blood
Oxygen
• Oxygen binds to an iron protein, called hemoglobin, to
form oxyhemoglobin.
• Since oxygen and hemoglobin molecules are unstable,
oxyhemoglobin releases oxygen into nearby cells.
• More oxygen is released when:
• Po2 decreases
• Carbon Dioxide concentration increases
• Blood becomes increasingly acidic
• Blood temperature increases
•Hypoxia is a deficiency of oxygen reaching the cells.
1. As carbon dioxide dissolved in plasma
•
If the partial pressure of the carbon dioxide is higher in the
tissues, more will dissolve in the plasma.
2. As a compound bonded to hemoglobin
•
Carbon dioxide binds to the protein part of hemoglobin, not
the iron, and therefore does not compete with the binding of
oxygen. This bond creates carbaminohemoglobin.
3. In the form of a bicarbonate ion
•
•
•
Carbon dioxide and water react to create carbonic acid.
Carbonic anhydrase is an enzyme in red blood cells that
speeds up the reaction.
Carbonic acid splits to become a hydrogen ion and
bicarbonate ion.
Gas
Transport
By Blood
Carbon Dioxide is
transported to the
lungs in 1 of 3 ways:
•As carbon
dioxide
dissolved in
plasma.
•As a
compound
bonded to
hemoglobin.
•In the form of a
bicarbonate
ion
Factors that Affect Breathing
• Central chemoreceptors sense changes in the cerebrospinal fluid
of carbon dioxide and hydrogen ions
• When more carbon dioxide is being exhaled, the blood and CSF
causes the breathing rate to decrease
• Hyperventilation is when someone is breathing really deep and
rapidly
• This causes an increase in breath
Diseases
• Laryngitis
• Hoarsness or lack of voice
• The mucus membrane of the larynx becomes inflamed and
swollen due to infection or an irritation from inhaled vapors
• Prevents the vocal chords from vibrating freely
Emphysema
• Progressive and pregenerative disease that destroys
alveolar walls
• As a result, surface area decreases and the volume of gases
exchanged through the membrane reduces
• Expiration becomes more difficult
• Caused by repeated exposure to respiratory irritants like
tobacco and pollution
Lung Cancer
• Division of cells that take the nutrients and oxygen out of normal
cells
• It can sometimes be developed from other cancer cells in
different parts of the body
• Cancer cells form tumors that block air passages and decrease
the exchange of gas
Works Cited
• Butler, Jakie, Lewis Ricki, Shier David. Eds. Hole’s Essentials of Human Anatomy and Physiology. New York:
McGraw-Hill,2006.429-447.Print.
• “Chapter 16 Outline Respiratory System.” PHED. Web. 14 May 2013<
http://people.emich.edu/pbogle/PHED_200/overheads/ch16_art/16_08.jpg
• How Stuff Works." http://science.howstuffworks.com/life/human-biology/question1391.htm. N.p., n.d.
Web. 8 May 2013. <science.howstuffworks.com/life/human-biology/question139.htm >.
• "Middle Nasal Conchae." http://s812.photobucket.com/user/krystalc/media/Ethmoid%20Bone/MiddleNasalConchae.jpg.html. N.p., n.d. Web. 3 May 2013.
<http://s812.photobucket.com/user/krystalc/media/Ethmoid%20Bone/MiddleNasalConchae.jpg.html
>.
• National Institutes of Health. “General Information About Paranasal Sinus and Nasal Cavity Cancer.”
National
Care Institute. 18 January 2013. Web. 14 May 2013<
http://www.cancer.gov/cancertopics/pdq/treatment/paranasalsinus/Patient/page1
• Powell, k. “What is the Trachea”. Wise Geek. 2003. Web. 14 May 2013< http://www.wisegeek.com/whatis-the- trachea.htm
• Tamarkin, Dawn. Respiratory Organs. 2011. STCC Foundation Press. Photograph