Ch.22- The Respiratory System Flashcards
The major function of the respiratory system is to…
supply the body with oxygen and dispose of carbon dioxide
What is the first stage of respiration and what occurs during this phase?
Pulmonary ventilation; air is moved into and out of the lungs
What is the second stage of respiration and what occurs during this phase?
External respiration; oxygen diffuses from the lungs to the blood and carbon dioxide diffuses from the blood to the lungs
What is the third stage of respiration and what occurs during this phase?
Transport of respiratory gases; oxygen is transported from the lungs to the tissue cells of the body, and carbon dioxide is transported from the tissue cells to the lungs
What is the fourth stage of respiration and what occurs during this phase?
Internal respiration; oxygen diffuses from blood to tissue cells, and carbon dioxide diffuses from tissue cells to blood
When does the lower respiratory system begin at?
the larynx and all structures below it
Name the 5 functions of the nose.
1) airway for respiration
2) moistens and warms entering air
3) filters and cleans inspired air
4) serves as a resonating chamber of speech
5) houses the olfactory receptors
What structure separates the nasal cavity from the oral cavity?
The palate (hard and soft)
What structure is located just superior to the nostrils and contains sebaceous and sweat glands and numerous hair follicles?
Nasal vestibule
What lines most of the nasal cavity?
Respiratory mucosa
What is the role of mucus?
to trap inspired dust, bacteria, and other debris. The mucus film also humidifies incoming air because of the high water content
What does a lysozyme do?
attacks and destroys bacteria
Natural antibiotics that help kill invading microbes
defensins
What benefit do the nasal conchae give?
they greatly increase the muscosal surface area exposed to air and enhance air turbulence in the cavity
What do the paranasal sinuses do?
they lighten the skull and may help warm and moisten the air
Inflammation of the nasal mucosa accompanied by excessive mucus production, nasal congestion, and postnasal drip
rhinitis
Inflamed sinuses
sinusitis
Where is mucus produced?
in the nose/nasal cavity
This structure connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly
Pharynx
The pharynx is aka…
the throat
This part of the pharynx serves only as an air passageway
nasopharynx
During swallowing, what moves superiorly to close off the nasopharynx and prevent food from entering the nasal cavity?
soft palate and uvula
This structure traps and destroys pathogens entering the nasopharynx in air
pharyngeal tonsil
This structure drains the middle ear cavities and allows middle ear pressure to equalize with atmospheric pressure
Pharyngotympanic (auditory) tubes
True or False.
Both swallowed food and inhaled air pass through the nasopharynx
False
True or False.
In the oropharynx, both swallowed food and inhaled air pass through
True
Similarly to the oropharynx, this structure serves as a passageway for food and air and is lined with stratified squamous epithelium
Laryngopharynx
What two processes of respiration is the actual respiratory system responsible for?
Pulmonary ventilation and external respiration
What two processes of respiration is the circulatory system responsible for?
Transport of respiratory gases, internal respiration
Why is molecular oxygen so important in order to breathe?
Because oxygen is the final electron acceptor in the ETC of cellular respiration, which ends up making ATP
What is the site of gas exchange?
Respiratory zone
What are the structures of the respiratory zone?
respiratory bronchioles, alveolar ducts, and alveoli
Conduits to gas exchange sites
Conducting zone
The upper respiratory tract involves…
organs in the head and neck, nose through larynx
The lower respiratory tract involves…
organs of the thorax, trachea through lungs
Airflow in lungs goes from the bronchi to…
bronchi–> bronchioles–> alveoli
What is the voice box?
larynx
What constitutes the roof of the nasal cavity?
ethmoid and sphenoid bones
What constitutes the floor of the nasal cavity?
hard and soft palates
What are vibrissae and what do they do?
Hairs that filter coarse particles from inspired air
What type of epithelium tissue makes up the respiratory mucosa?
Pseudostratified ciliated columnar epithelium
What triggers sneezing?
Sensory nerve endings
What part of the respiratory mucosa moves contaminated mucus posteriorly to throat?
cilia
Inspired air is warmed by what part of the respiratory mucosa?
plexuses of capillaries and veins
What is the role of the nasal conchae during exhalation?
To reclaim heat and moisture
Passageway for food and air from the level of the soft palate to the epiglottis
Oropharynx
What is the opening to the oral cavity?
isthmus of the fauces
What is the smallest part of the pharynx?
oropharynx
This part of the pharynx extends to the larynx where it is also continuous with the esophagus
laryngopharynx
What are the 3 functions of the larynx?
1) provides a patent airway
2) routes air and food into proper channels
3) voice production
Splitting point where there is a diversion to esophagus and trachea
Larynx
What covers the laryngeal inlet during swallowing?
Epiglottis
How do the intrinsic muscles control vocal cords?
They pull on the cartilages and cause them to pivot
Are the vestibular folds true or false vocal cords?
False
Are the false vocal cords superior or inferior?
Superior
What is the role of the vestibular folds?
helps to close the glottis during swallowing
Explain valsalva’s maneuver?
The glottis closes to prevent exhalation while the abdominal muscles contract and pressure rises. It is used to help empty the rectum or stabilize the trunk during heavy lifting
What are the three layers that make up the trachea?
mucosa, submucosa, adventitia
What layer of the trachea is outermost and made up of connective tissue that encases 16-20 C-shaped rings of hyaline cartilage?
adventitia
Where does the trachealis muscle connect?
posterior parts of cartilage ring
What is the carina?
Point where trachea branches into two bronchi
What propels mucus upward?
Cilia
What type of cell secretes mucus?
Goblet cell
The branching pattern of the bronchi is called the…
bronchial respiratory tree
The right main bronchus is…
wider, shorter, and more vertical than the left
What does the main bronchus branch into?
Lobar bronchi (three for the right, two for left)
Is there cartilage found in bronchioles?
No
As bronchi turns into bronchioles, structural changes occur and one of these is that cartilage rings give way to…
Plates
The respiratory zone is defined by…
the presence of alveoli
When does the respiratory zone begin?
As the terminal bronchioles feed into respiratory bronchioles
What accounts for most of the lungs volume?
Alveoli
What structure is found within alveoli that allows for gas exchange?
Capillaries
Histamine is a…
Bronchoconstrictor
What is the function of alveoli pores?
They connect adjacent alveoli and allow air pressure throughout the lung to be equalized
Alveolar walls are made up of a single layer of…
Type 1 epithelial cells
What do alveolar walls allow for?
gas exchange by simple diffusion
What do the alveolar walls secrete?
angiotensin converting enzyme (ACE)
What type of cell secretes surfactant?
Type II epithelial cells
What is the function of surfactant?
Keeps alveoli inflated so they don’t collapse
Describe the left lung and how it differs from the right.
The left lung is smaller, separated into two lobes by an oblique fissure
Describe the right lung and how it differs from the left.
The right lung has three lobes separated by oblique and horizontal fissures
What are the three functions of the pleura and pleural fluid?
1) reduction of friction
2) creation of pressure gradients
3) compartmentalization
Pulmonary circulation has _____ pressure and ______ volume while systemic circulation has ______ pressure and _____ volume
low, high, high, low
What provides oxygenated blood to the actual lung tissue?
bronchial arteries
Bronchial arteries supply all lung tissue except…
the alveoli
True or False.
In order to breathe in and out, there must be pressure differences
True
According to Boyle’s law, as pressure increases, volume…
Decreases
According to Charle’s law, as temperature increases, volume….
increases
Dalton’s law states that…
The total pressure of a gas mixture is equal to the sum of the partial pressures of it’s individual gases
What is atmospheric pressure?
Pressure exerted by the air surrounding the body; 760 mmHg
What is negative respiratory pressure?
Less than Patm
What is positive respiratory pressure?
Greater than Patm
What is intrapulmonary pressure?
Pressure in the alveoli that fluctuates with breathing
True or False.
Intrapulmonary pressure always eventually equalizes with Patm
True
What is intrapleural pressure?
Pressure in the alveoli that fluctuates with breathing
Which one, intrapulmonary or intrapleural pressure is always negative?
Intrapleural; Pip
What are the two things that cause negative intrapleural pressure?
Elastic recoil of lungs and surface tension of alveolar fluid
What is transpulmonary pressure?
Intrapulmonary pressure - intrapleural pressure
The greater the transpulmonary pressure, the _____ the lungs
larger
Atelectasis is…
lung collapse
What is the goal of gas flow?
To equalize pressure
What happens to intrapulmonary pressure during inspiration?
Drops to -1 mmHg
What five muscles contribute to inspiration?
sternocleidomastoid, scalenes, external intercostals, diaphragm, pectoralis minor
What happens to intrapulmonary pressure during quiet expiration?
Rises to +1 mmHg
What is the difference between quiet and forced expiration?
Quiet expiration is normally a passive process and forced expiration if an active process that uses abdominal and internal intercostal muscles
Inspiratory muscles must overcome what three factors that hinder air passage and pulmonary ventilation?
Airway resistance, alveolar surface tension, and lung compliance
What is the major nonelastic source of resistance to gas flow?
friction
With increased resistance, gas flow ________
decreases
Where does resistance to flow disappear?
At the terminal bronchioles where diffusion drives gas movement
What dilates bronchioles and decreases air resistance?
Epinephrine
What is surface tension in relation to alveoli?
Liquid molecules are attracted to one another at the gas-liquid interface of alveoli and they resist any force that tends to increase the surface area of the liquid
What does surfactant do?
Reduces surface tension of alveolar fluid and discourages alveolar collapse
What does the liquid coating of alveoli tend to do?
Reduce the alveoli to the smallest possible size
How does surfactant reduce surface tension?
It disrupts hydrogen bonding by becoming interspersed between H20 molecules
A measure of the change in lung volume that occurs with a given change in transpulmonary pressure
Lung compliance
Distensibility (stretching) of lung tissue and alveolar surface tension create what situation?
High lung compliance
Name the values for the partial pressures:
Inspired air
Po2:
Pco2:
Po2: 159
Pco2:0.3
Name the values for the partial pressures:
Alveolar air
Po2:
Pco2:
Po2: 104
Pco2:40
Name the values for the partial pressures:
Oxygenated blood
Po2:
Pco2:
Po2: 95
Pco2: 40
Name the values for the partial pressures:
Tissue fluid
Po2:
Pco2:
Po2: 40
Pco2: 46
Name the values for the partial pressures:
Deoxygenated blood
Po2:
Pco2:
Po2: 40
Pco2: 46
Name the values for the partial pressures:
Expired air
Po2:
Pco2:
Po2: 116
Pco2: 32
The central chemoreceptors monitor…
CO2
The peripheral chemoreceptors in the aortic and carotid bodies monitor…
O2
The depth and rate of breathing is controlled by…
The central chemoreceptors
Ventilation increase is controlled by…
The peripheral chemoreceptors
Where are peripheral chemoreceptors located?
Carotid and aortic bodies
Where are central chemoreceptors located?
Surface of medulla
What stimulates the central chemoreceptors?
H+
Usually due to inadequate pulmonary gas exchange
hypoxemic hypoxia
Inadequate circulation
Ischemic hypoxia
Metabolic poison (cyanide)
Histotoxic hypoxia
The primary effect of hypoxia is what?
Tissue necrosis
