What is the major function of the Respiratory system?
To supply the body with oxygen and dispose of carbon dioxide.
What are the four things that must happen?
Pulmonary ventilation, external respiration, transport of respiratory gases, internal respiration
Pulmonary ventilation, external respiration, transport of respiratory gases and internal respiration are collectively called what?
What is pulmonary ventilation?
Movement of air inot and out of the lungs so that gases there are continuously changed and refreshed(commonly called breathing)
What is external respiration?
Movement of oxygen from the lungs to the blood and of carbon dioxide from the blood to the lungs.
What is transport of respiratory gases?
transport of oxygen from the lungs to the tissue cells of the body, and of carbon dioxide from the tissue cells to the lungs.
How is transport of respiratory gases accomplished?
By the cardiovascular system using blood as the transporting fluid.
What is internal respiration?
Movement of oxygen from blood to the tissue cells and of carbon dioxide from tissue cells to blood.
Why are the respiratory and circulatory system closely coupled?
Only pulmonary ventilation and external respiration, are the special responsibility of the respiratory system, but it cant accomplish its primary goal of obtaining oxygen & eliminating carbon dioxide unless transport of respiratory gases and internal respiration also occurs.
Because the respiratory system moves air, what else is it also involved in?
The sense of smell & speech
What does the respiratory system include?
The nose, nasal cavity, pharnyx, larnyx, trachea, bronchi and their smaller branches & the lungs(terminal air sacs or alveoli).
Functionally the system consists of what two zones?
The respiratory zone & the conducting zone.
What is the respiratory zone?
The actual site of gas exchange.
What is the respiratory zone composed of?
The respiratory bronchioles, alveolar ducts, and alveoli, all microscopic structures.
What is the conducting zone?
All other respiratory passage ways, which provide fairly rigid conduits for air to reach the gas exchange sites.
What do the conducting zone organs do?
Cleanse, humidify and warm incoming air.
What purpose does the conducting zone serve?
It allows the air to have fewer irritants(dust, bacteria,ect)
What is the only external visible part of the respiratory system?
What are the functions of the nose?
Airway for respiration, moistens & warms entering air, filters & cleans inspired air, serves as a resonating chamber for speech, and houses olfactory(smell) receptors.
What two structures are the nose divided into?
External nose & internal nasal cavity
What do the surface area of the nose include?
The root(area between the eyebrows), bridge, and dorsum nasi(anterior margin)
Just inferior to the apex is a shallow vertical groove called what?
The external openings of the nose are bounded laterally by what?
The flared alae.
What does the skin of the nose contain many of ?
The nasal cavity is divided by what?
A midline nasal septum
What forms the nasal septum?
anteriorly by the septal cartilage and posteriorly by the vomer bone and perpendicular plate of the ethmoid bone.
The nasal cavity is continuous posteriorly with what?
The nasal portion of the pharynx through the posterior nasal apertures
What are the posterior nasal apertures also called?
The roof of the nasal cavity is formed by what?
The ethmoid and sphenoid bones of the skull.
The floor is formed by what?
What does the palate separate?
The nasal cavity from the oral cavity
What is it called anteriorly where the palate is supported by the maxillary porcesses and palatine bones?
The hard palate
What is the soft palate?
The unsupported posterior portion.
What is the part of the nasal cavity just superior to the nostrils called?
what is the nasal vestibule lined with?
skin, containing sebaceous & sweat glands and numerous hair follicles.'
What are the hairs of the nose also called?
The rest of the nasal cavity is lined with what?
Two types of mucus membrane.
What are the two mucus membranes called?
Olfactory mucosa & respiratory mucosa
What does the olfactory mucosa line?
the slitlike superior region of the nasal cavity.
what does the olfactory muscosa contain?
What is the respiratory mucosa?
pseudostratified ciliated columnar epithelium
What does the respiratory mucosa conain?
what do mucous cells secrete?
what do the serous glands secrete?
watery fluid containing enzymes
what do the mucous and serous glands secrete each day?
lysozyme, an antibacterial enzyme
what attacks and destroys bacteria chemically?
the epithelial cells of the respiratory mucosa also secrete what?
what are defensins?
natural antibiotics that help get rid of invading microbes
the high water content of the mucus does what?
acts to humidify the inhaled air
the ciliated cells of the respiratory mucosa create what?
a gentel current that moves the sheet of contaminated mucus posteriorly toward the throat, where it is swallowed and digested by the stomach juices
when exposed to cold air what becomes sluggish allowing mucus to accumulate in the nasal cavity & then dribble out the nostril?
The nasal mucosa is richly supplied with what?
sensory nerve endings
what is the purpose of a sneeze?
It is a crude way of expelling irritants from the nose, such as dust or pollen
What helps to warm incoming air into the nostrils?
rich plexuses of capillaries & thin walled veins underlie the nasal epithelium
why are nosebleeds common?
Because of the abundance of the capillaries and the superficial location
Protruding medially from each lateral wall of the nasal cavity is what?
three scroll like mucosa covered projections
What are the three scroll like mucosa called?
superior, middle, and inferior nasal conchae
The groove inferior to each concha is what?
the nasal meatus
what is the size of particles that make it past the nasal cavity?
few larger than 6mm
Conchae and nasal mucosa function during what?
inhalation to filter heat and moisten air and also act during exhalation to reclaim this heat and moisture
The nasal cavity is surrounded by a ring of what?
Where is the paranasal sinuses located?
in the frontal, sphenoid, ethmoid, and maxillary bones
What can cause rhinitis?
cold viruses, strep bacteria, and alergens.
what is rhinitis?
inflammation of the nasal mucosa, accompanied by excessive mucus production, nasal congestion and postnasal drip.
what explains the typical nose to throat to chest progression of colds?
because the nasal mucosa is continuous with them
what is sinusitis?
What causes a sinus headache?
when the passageways connecting the sinuses to the nasal cavity are blocked with mucus or infectious material, the air in the sinus cavities is absorbed, which results in a partial vaccum