Respiratory System Flashcards
Define the terms ventilation, external respiration, internal respiration, and cellular
respiration
ventilation (breathing) - insures continuous refreshing of †he gas in the alveoli of the lungs
external respiration- takes place in the pulmonary capillaries, across the respiratory membrane, the blood take on O2 and gives up CO2
- we breathe CO2 out
internal respiration - takes place in the systemic capillaries, the blood gives up O2 and takes on CO2
- we breathe O2 in
cellular respiration - metabolic process in which ATP is produced
Distinguish between the conducting zone and the respiratory zone of the respiratory
system. Anatomically, what is the first structure in the respiratory zone?
conducting zone - consists of all of the respiratory passageways from the nose to the respiratory bronchioles (carry air to the gas exchange sites)
- also cleans, humidify, and warm incoming air (so air reaching the lungs has fewer irritants and is warm and damp)
respiratory zone - the actual site of gas exchange, is composed of the respiratory bronchioles, alveolar ducts, and alveoli
Identify the 4 structures comprising the upper respiratory system
nose, nasal cavity
paranasal sinuses
pharynx
What are the 5 general functions of the nostrils and nasal cavity?
What structural features
support these functions?
COME BACK
only external part of the respiratory system
- provides an airway for respiration
-moistens and warms entering air
-filters and cleans inspired air
-serves as a resonating chamber for speech
- houses the olfactory (smell) receptors
divided into external nose and internal nasal cavity
the nasal cavity is where the air enters, it is divided by a midline nasal septum, the part of the nasal cavity just superior to the nostril is the nasal vestibule, which is lined with skin containing sebaceous and sweat glands and numerous hair follicles. the hairs filter coarse particles (dust , pollen) from inspired air. the east of the nasal cavity is lined with mucous membranes
Name and describe the location of the three levels of the pharynx.
How does the
epithelial lining change from one level of the pharynx to another?
How does the
change in epithelium support the function of each level of the pharynx?
nasopharynx - ONLY an air passageway
- during swallowing, the soft palate and its pendulous uvula move superiorly, closing it off and prevent food from entering
*pseudostratified ciliated epithelium - propels mucus where the nasal mucosa leaves off
- on the posterior wall, the pharyngeal tonsil traps and destroys pathogens entering the air
oropharynx- food and air
*stratified squamous epithelium - accommodated the increased friction and chemical trauma (hot or spicy foods) accompanying food passage
laryngopharynx - food and air
*stratified squamous epithelium
-continuous with the esophagus, which conducts food and fluids to the stomach
- during swelling, food has the right of way and air passage stops temporarily
What are the 3 functions of the larynx? What structural features support these functions?
(voice box)
attached to the hyoid bone, opens into the laryngopharynx
1.) Provide a patent (open) airway
2.) Act as a switching mechanism to route air and food into the proper channels
3.) Voice production (houses the vocal chords)
9 hyaline cartilages connected my membranes and ligaments and the epiglottis
the epiglottis - keeps food out of the lower respiratory passages (the larynx), if food does get there, we cough to get it out
Describe the general location and function of each of the following: thyroid cartilage,
cricoid cartilage, epiglottis, glottis, arytenoid cartilage, vestibular folds (false vocal
cords), vocal folds (true vocal cords).
thyroid cartilage- shaped like an upright open book. the book spine is known as the laryngeal prominence (Adams apple)
cricoid cartilage (anchored to trachea), arytenoid cartilage (pyramid shaped, anchors the vocal chords), and cuneiform form the posterior walls of the larynx -
epiglottis- the ninth cartilage, flexible and spoon shaped, almost entirely covered by taste big containing mucosa.
covered the laryngeal inlet when swallowing occurs
glottis- the vocal folds and the medial opening between them in which air passes
vestibular folds (false vocal cords)- mucousal folds that play no direct part in sound production but help close the glottis when we swallow
– when the vocal folds vibrate, sound is produced as air rushes from the lungs
vocal folds (true vocal cords).-vocal chords composed of elastic fibers form the core of mucosal folds (true vocal chords) which appear white because they lack blood vessels
Of what type of cartilage are the thyroid cartilages composed?
hyaline cartilage
Identify and describe the three layers of the tracheal wall.
superior to Inferior
- mucosa made of pseduostratified ciliated columnar epithelium with inter speed goblet cells, and lamina proprietary or CT or lamina propria
- submucosa - will cells and seromucous glands
(hyaline cartilage)
- adventitia
Name the branches of the bronchial tree, beginning with the tubes formed by the
branching of the trachea.
branch from the trachea into the primary bronchus , then the lobar secondary bronchus , into the segmental (tertiary) bronchus.
right lung has three lobes
How does the structure of the bronchial walls change as the tubes branch and become
smaller?
-Irregular patches of cartilage replace the cartilage rings and by the time the bronchioles are reached, the tube walls no longer contain supportive cartilage.
-the mucosal epithelium thins as it changes from pseudo stratified columnar to simple columnar to simple cuboidal in the terminal bronchioles.
Mucus producing cells and cilia are sparse in the bronchioles.
- The amount of smooth muscle increases as passage ways become smaller, allows the bronchioles to provide resistance to air passage under certain conditions
Which of the respiratory system structures are considered part of the conducting zone?
of the respiratory zone?
Conducting zone:
- trachea
- primary bronchus
- lobar (secondary) bronchus
- segmental (tertiary) bronchus
Respiratory zone:
- respiratory bronchioles
- alveolar ducts
- alveoli
- alveolar sacs
- the respiratory membrane
In what three ways does the upper respiratory tract “condition” air before it reaches the
lungs?
cleanse, humidify, and warm incoming air
Describe the structure of an alveolus.
gap filled air spaces surrounded by type 1 alveolar cells that form the spherical structures and type 2 alveolar cells that secrete surfactant
Distinguish between type I and type II alveolar cells.
type 1 alveolar cells that form the spherical structures and are squamous epithelial cells
and type 2 alveolar cells that secrete surfactant and are cuboidal epithelial cells
What is the function of type II alveolar cells? of alveolar macrophages?
type 2 alveolar cells that secrete surfactant and also secrete a number of antimicrobial proteins that are important elements of innate immunity.
alveolar macrophages crawl freely along alveolar surfaces consuming bacteria, duct and other debris
Describe the structure and function of the respiratory membrane?
flimsy and thin, surrounded type 1 alveoli cells
capillary and alveolar walls fused their basement membranes to form this
blood barrier, blood forms on one side, gas on the other
gas exchanges occur readily by simple diffusion across the respiratory membrane (passes from the alveolus to the blood and blood to gas filled alveolus)
Distinguish between the following levels of lung organization: lobe, bronchopulmonary
segment, and lobule.
What is the name of the airway and artery associated with each (?) of
these parts of the lung?
lobe- the left lungs are divided into superior and inferior lobes by the oblique fissure, the right lung is divided into super, middle and inferior lobes by the oblique and horizontal fissures
each lobe contains
a number of pyramid shaped
bronchopulmonary segments- separated by CT septa.
right lung has 10 and left has 8 to 10. each segment has its own artery and vein.
* are clinically important because pulmonary disease is often confined to one or few segments and their CT partitions allow diseased segments to e surgically removed without damaging neighboring segments or impairing blood supply.
lobule- smallest subdivisions of the lungs that are visual to the naked eye
- on lungs surface look like hexagons , size of a pencil eraser. a large bronchiole and its branches serve each lobe.
Identify and describe the location of the pleural membranes and pleural cavity.
is a double layered serosa, produces pleural fluid, divides thoracic cavity into three
parietal layer - covers the thoracic wall and superior face of the diaphragm.
- it continues around the heart and between the lungs, forming the lateral walls and enclose the lung root
from there, the pleurae extends as the visceral pleura to cover the external lung surface, dipping into and lining the fluid
Identify the major functions of pleural fluid.
this lubrication secretion allows the lungs to glide over the thorax during our breathing movements
Describe the phenomenon of ventilation-perfusion coupling.
How does ventilation-
perfusion coupling enhance respiratory efficiency?
influences expiration
matching alveolar ventilation (the movement of gas during breathing) with pulmonary blood perfusion (pulmonary blood circulation, delivering oxygen to the body tissues)
Describe the mechanics of inspiration and expiration (i.e., how do we move air into and
out of our lungs?).
inspiration- the gas exchange that occurs between the systemic capillaries and the tissues. CO2 enters the blood and O2 and O2 leaves the blood and enters the tissues.
expiration- gas exchange that happens in the lungs
*oxygen enters the pulmonary capillaries and carbon dioxide leaves the blood and enters the alveoli
*factors influencing this process:
-
partiial pressure gradient
- thickness of the respiratory membrane
- surface area available
- ventilation-perfusion
What is intrapleural pressure? How is intrapleural pressure created?
pressure within the pleural cavity , usually negative relative to intrapulmonary pressure (pressure within alveoli)
-4 mmHg , 756 mmHg
is created when the forces that cause the lungs to collapse (pulling the visceral layer in) are opposed by the natural elasticity of the chest wall to pull the thorax outward. neither force wins because of pleural fluid
Describe the fluctuations in intrapleural pressure during inspiration and expiration.
inspiration - intrapleural pressure pulls lungs outwards, towards walls of thoracic cavity, decreasing pressure between lungs and the wall, helping it adhere
so pressure rises ?
expiration - the lungs are pulled inwards, so pressure decreases to ?
What is Boyle’s Law? How does this law relate to the mechanics of pulmonary
ventilation?
the pressure of the gas is inversely proportional to the vol of its container (the less vl, the greater the pressure because gas molecules are bouncing off a compact space)
this relates to pulmonary ventilation because it explains the intrapulmonary pressure changes
Is alveolar (i.e., intrapulmonary) pressure higher or lower than atmospheric pressure
during inspiration? during expiration?
inspiration - pressure is lower because thoracic cavity expands, so size of lungs is expanding
until it reaches atmospheric pressure 760 mmHg
expiration - pressure is higher because vl of lungs decreases
until it reaches atmospheric pressure 760 mmHg
What effect do changes in thoracic volume have on intrapulmonary pressure?
that determines how much the lungs can expand and collapse during inspiration and expiration, which affects the pressure
What muscles are involved in quiet inspiration? What nerve innervates the diaphragm?
diaphragm and external intercostal muscles
phrenic nerve
Which phase of quiet breathing is a passive process?
air flowing in and out of the lungs, down the pressure gradient until the atmospheric pressure is 0
What forces are constantly acting to collapse the lungs? Which of these forces is
normally most responsible for quiet exhalation?
- the lungs natural tendency to recoil, because of the elasticity, lungs always assume the smallest size possible
(most responsible for quiet exhalation) - the surface tension of the alveolar fluid - the fluid lining the alveoli attract each other, this produces a surface tension that works to draw alveoli to their smallest dimension.
Identify the three main physical factors that influence pulmonary ventilation.
1.) airway resistance - gas flow is inverse to air way resistance
2.) alveolar surface tension - at gas-liquid boundaries, the molecules of the liquids are strongly attracted to each other than to gas molecules, this creates surface tension.
3.) lung compliance - healthy lungs are very stretchy
