RESPIRATORY SYSTEM Flashcards
What is the respiratory system?
A system of tubes that delivers air to the lungs and exchanges gasses
Respiratory system and the _____ collaborate to
regulate the body’s acid–base balance
urinary system
What are some of the 8 functions of the respiratory system?
- Gas exchange: O2 and CO2 exchanged between blood and air
- Communication: speech and other vocalizations
- Olfaction: sense of smell
- Acid-Base balance: influences pH of body fluids by eliminating CO2
- Blood pressure regulation: by helping in synthesis of angiotensin II
- Blood and lymph flow: breathing creates pressure gradients between thorax
and abdomen that promote flow of lymph and blood - Blood filtration: lungs filter small clots
- Expulsion of abdominal contents: breath-holding assists in urination,
defecation, and childbirth((Valsalva maneuver)
What are the 6 principal organs of the respiratory system?
Nose, pharynx, larynx, trachea, bronchi, lungs
The conducting zone of the respiratory system includes?
- Nostrils through the major bronchioles
- Passages that serve only for air flow
- no gas exchange*
Respiratory zone of the respiratory system includes?
alveoli and other gas exchange regions
The upper respiratory system composed of the ____ through the ___
Nose through larynx
The lower respiratory system is the _____ to the ____
trachea through the lungs
What are the functions of the nose?
- Warms, cleans, humidifies air
- Olfactory function
- resonating chamber for voice
What are the Ala nasi
flared portion at lower end of
nose shaped by alar cartilages and
dense connective tissue
The nose extends from the ___ to the ___
Nostrils to the Choanae
the chamber just inside nostrils
lined with stratified squamous epithelium
and vibrissae is called the
Vestibule
The chamber behind the vestibule is occupied by the ___
Nasal conchae
What are the nasal conchae? their functions?
- Three folds of tissue (superior, middle, inferior)behind the vestibule
- Create turbulence to insure all air comes into contact with Mucus membranes
- Cleans, warms, moistens the air
What type of epithelium makes up the Olfactory epithelium
Ciliated pseudostratified columnar
epithelium
What are the Nasal fossae?
right and
left halves of nasal cavity
The Pharynx extends from the ___ to the ___
Choanae to the larynx
What are the three regions of the pharynx?
-Nasopharynx- contains
pharyngeal tonsil
-oropharynx-Space between soft palate and epiglottis-Contains palatine tonsils
-Laryngopharynx(Epiglottis to cricoid cartilage)( Esophagus begins at that point)
What is the larynx?
- The voice box
- A cartilaginous chamber
What is the function of the larynx?
- to keep food and drink out of the airway
- Produce sound speech
What is the epiglottis?
- Guards the superior opening of the larynx
- Closes airway and directs food to esophagus behind it
How many cartilages make up the larynx?
What are they?
9
- Epiglottic
- Thyroid
- Cricoid
- Three small paired cartilages
the two types of interior folds within the larynx?
Functions?
- Superior vestibular folds- Close the larynx during swallowing
- Inferior vocal cords- produce sound
What is the glottis?
—the vocal cords and the
opening between them
What is the function of the Superior extrinsic muscles?
they Elevate the larynx during swallowing
What is the function of the Deep intrinsic muscles
operate the vocal cords
What is the trachea?
- The wind pipe
- inferior to the larynx
How is the trachea supported?
16-20 C-shaped rings of hyaline cartilage
What epithelium lines the trachea? what are its specific functions?
-ciliated pseudostratified columnar epithelium -make up the Mucociliary escalator: mechanism for debris removal -Goblet cells produce some mucus
What is the middle tracheal layer?
-connective tissue
beneath the tracheal epithelium
– Contains lymphatic nodules, mucous and
serous glands, and the tracheal cartilages
What is the outermost layer of trachea called? its composition and function?
-Called the Adventitia
– Fibrous connective tissue that blends into
adventitia of other organs of mediastinum
The trachea branches into the left and right ___
Main Bronchi
What is the Carina?
internal medial ridge
in the lowermost tracheal
cartilage
What are the for main anatomical features of the lungs?
-Base: broad concave portion
-Apex: tip that projects just
above the clavicle
-Costal surface: pressed against the ribcage
-Mediastinal surface: faces
medially toward the heart
How many lobes does the right lung have? name them what separate them?
3
-Superior, middle, inferior
-separated by horizontal and
oblique fissure
How many lobes does the left lung have? name them what separate them?
2
- superior and inferior
- a singe oblique fissure
the ____ bronchus is slightly wider and more
vertical than left
Right
You have ___ Primary Bronchi Which branch into ___ bronchi
2
Secondary (Lobar)
How many Lobar (secondary) bronchi does each lung have?
- Right: three one for each lobe
- Left: two once for each lobe
The lobar (secondary) bronchi branch into ___ bronchi
Segmental(tertiary) bronchi
How many segmental (tertiary) bronchi does each lung have?
- Right : 10
- Left: 8
All bronchi are lined with ______epithelium
ciliated pseudostratified
columnar
Tertiary Bronchi branch into ___ that divide into ____
- Bronchioles
- 50-80 terminal branches
Bronchioles have ____ epithelium
ciliated cuboidal epithelium
terminal Bronchioles are the final branches of the _____ zone of the respiratory system
Conducting zone
Each terminal bronchiole gives off two or more smaller _____
bronchioles
Respiratory
Respiratory bronchioles are the beginning of the ___ zone
respiratory
Respiratory bronchioles have ___ budding from their walls
Alveoli
Respiratory bronchioles end in
alveolar sacs
What are alveolar sacs
clusters of alveoli arrayed around a central space called the
atrium
How many alveoli does each lung contain?
150 million
How much gas exchanging surface area is in each lung
70 square meters
What are the three types of alveolar cells? their basic functions?
- Squamous( type I):Gas exchange 95% of surface
- Great (type II):maintenance 5% of surface
- Alveolar macrophages (dust cells): eat dust
How do type II alveolar cells function to maintain the lungs?
- They repair Type I cells when they are damaged
- they secrete pulmonary surfactant
How are type I alveolar cells connected to capillaries?
via a shared basement membrane
The capillaries the surround the alveoli are supplied by the ____
pulmonary artery
What is the Respiratory membrane?
thin
barrier between the alveolar
air and blood
What is the respiratory membrane composed of?
– Squamous alveolar cells – Endothelial cells of blood capillary – Their shared basement membrane
What is the serous membrane that covers the lungs?
the visceral pleura
What is the Parietal pleura?
—adheres to mediastinum, inner surface of the rib
cage, and superior surface of the diaphragm
What is the pleural cavity?
potential space between pleurae
What are the tree functions of the pleurae and pleural fluid
– Reduce friction
– Create pressure gradient
• Lower pressure than atmospheric pressure; assists lung inflation
– Compartmentalization
• Prevents spread of infection from one organ in mediastinum to others
What is Breathing (pulmonary ventilation)
a repetitive
cycle of inspiration (inhaling) and expiration (exhaling)
What is the respiratory cycle?
one complete inspiration and expiration
Flow of air in and out of lung depends on a_____ between air within lungs and outside body
Pressure gradient
What are the three Respiratory muscles?
- The diaphragm
- Internal and external intercostal muscles
- Scalenes
what occurs When the diaphragm contracts
The diaphragm flattens enlarging the thoracic cavity moving air into the lungs
What occurs when the diaphragm relaxes?
the diaphragm bulges upwards compressing the lungs and expelling air
What is normal quiet respiration
while at rest, effortless, and automatic
What is forced respiration
deep, rapid breathing, such as during exercise
What is normal quiet expiration?
Energy saving passive emptying of the lungs due to elasticity of the lungs
What are valsalva maneuvers?
onsists of taking a deep breath,
holding it by closing the glottis, and then contracting
the abdominal muscles to raise abdominal pressure
and push organ contents out
– Childbirth, urination, defecation, vomiting
Automatic breathing is controlled by ___ pairs of respiratory centers in the ___ of the ___ and ___
- Three
- Reticular formation
- Medulla oblongata
- Pons
the three pairs of respiratory centers are called respiratory ___
groups
What are the three respiratory groups?
-Ventral respiratory group (VRG)
-Dorsal respiratory group (DRG)
-Pontine respiratory group
(PRG)
What are the functions of the Ventral respiratory group (VRG)
-This is the primary generator of respiratory rhythm
-inspiratory neurons
fire for about 2 seconds
-Expiratory neurons in eupnea fire for about 3
seconds
-Produces a respiratory rhythm of 12 breaths per
minute
What are the functions of the Dorsal respiratory group (DRG)?
- Modifies the rate and depth of breathing
* Receives influences from external sources
What are the functions of the Pontine respiratory group?
Modifies rhythm of the VRG by outputs to both the VRG and DRG – Adapts breathing to special circumstances such as sleep, exercise, vocalization, and emotional responses
What is Hyperventilation
anxiety-triggered state in which
breathing is so rapid that it expels CO2 from the body
faster than it is produced
Central chemo receptors detect pH change in the ___
cerebrospinal fluid
What is the function of stretch receptors in the smooth muscles of the bronchi and bronchioles?
– Respond to inflation of the lungs
– Inflation (Hering-Breuer) reflex: triggered by excessive
inflation
• Protective reflex that inhibits inspiratory neurons and stops
inspiration
What are irritant receptors?
Receptors in the epithelial cells of the airway that detect irritants and trigger appropriate reactions
Where do voluntary control of breathing originate? how are signals sent
-motor cortex of frontal lobe
-Sends impulses down corticospinal tracts to respiratory
neurons in spinal cord, bypassing brainstem
Flow of air and fluid is directly proportional to the _____ difference between the two points
Pressure
Flow of air and fluid is inversely proportional to the ___
resistance
1 atm of pressure (sea level) equals how many mm Hg?
760
Boyle’s law states that___
—at a constant temperature, the pressure
of a given quantity of gas is inversely proportional to
its volume
How is Boyle’s law applied to lunges?
- If lung volume increases than pressure will decrease causing an influx of air
- if lung volume decreases pressure increases. once pressure is above atm pressure than the air will flow out
What is the medical unit for pressure
cm H2O
What is the measurment of cm H2O? why is it used?
-This measures how far a column of water would be moved
by a given pressure
-This is more sensitive than mm Hg, since Hg (mercury) is a
heavy liquid
What is the conversion of mm Hg to cm H2O
1 mm Hg = 1.4 cm H2O
What is Intrapleural pressure?
the slightly negative pressure
that exists between the two pleural layers
What is charles law?
volume of a gas is directly
proportional to its absolute temperature
How is charles law applied to lungs
Air in warmed when inhaled so the volume of air will increase by the time it reaches the alvoli
what is a Pneumothorax?
—presence of air in pleural cavity
-Causes lungs to collapse due to lose of interpleural pressure
Increasing resistance ____ airflow
Decreases
What two factors influence airway resistance?
bronchiole diameter and pulmonary compliance
What is Pulmonary compliance
the ease with which the lungs can expand
What is Physiologic (total) dead space
sum of anatomic dead space and any
pathological alveolar dead space
How do you calculate Alveolar ventilation rate (AVR)
Air that ventilates alveoliamount inhaled minus amount in deadspace (350 mL) × respiratory rate (12 bpm) = 4,200
mL/min.
What is a Spirometer?
a device that recaptures expired breath and
records such variables as rate and depth of breathing,
speed of expiration, rate of oxygen consumption, and
respiratory volumes and capacities
What is the tidal volume?
volume of air inhaled and exhaled in one cycle of
breathing (500 mL)
What is Inspiratory reserve volume?
air in excess of tidal volume that can
be inhaled with maximum effort (3,000 mL)
What is Expiratory reserve volume?
air in excess of tidal volume that can
be exhaled with maximum effort (1,200 mL)
What is Residual volume?
air remaining in lungs after maximum expiration (1,300 mL)
What is Vital capacity?
total amount of air that can be inhaled and then exhaled with maximum effort
– VC = ERV + TV + IRV (4,700 mL)
– Important measure of pulmonary health
What is the Functional residual capacity?
amount of air remaining in lungs after a normal tidal expiration
– FRC = RV + ERV (2,500 mL)
What is total lung capacity?
Total lung capacity: maximum amount of air the lungs can contain
– TLC = RV + VC (6,000 mL)
What are restrictive respiratory disorders?
those that reduce pulmonary
compliance
– Any disease that produces pulmonary fibrosis such as black lung
disease, tuberculosis
– Limit the amount to which the lungs can be inflated
– TLC, FRC, and others go down
What are obstructive respiratory disorders?
those that interfere with airflow by
narrowing or blocking the airway
– Asthma, chronic bronchitis (emphysema combines elements of
restrictive and obstructive disorders)
– Make it harder to inhale or exhale a given amount of air
– TLC, FRC, and others go up lungs hyperinflate to resistance
What is Eupnea?
Normal breathing
Tidal volume 500
12-15bpm
What is Apnea?
temporary cessation of breathing
What is Dyspnea?
labored, gasping breathing; shortness of breath
What is Hyperpnea?
—increased rate and depth of breathing in response to
exercise, pain, or other conditions
What is Hyperventilation?
—increased pulmonary ventilation in excess of metabolic
demand
What is Hypoventilation?
reduced pulmonary ventilation leading to an increase in
blood CO2
What is Kussmaul respiration?
deep, rapid breathing often induced by acidosis
What is Orthopnea?
—dyspnea that occurs when person is lying down
What is Respiratory arrest?
permanent cessation of breathing
What is Tachypnea?
—accelerated respiration
What is dalton’s law?
—total atmospheric pressure is the sum
of the contributions of the individual gases
What is partial pressure?
the separate contribution of each gas in a
mixture
according to daltons law, At 760mm Hg what portion of that pressure comes from nitrogen nitrogen composes 78.6% of the atmospere
PN2 = 78.6% × 760 mm Hg = 597 mm Hg
What three factors make alveolar air different from inspired air?
- It is humidified, PH2O is 10X than inhaled air
- It is mixed with residual air from previous cycles
- Alveolar air exchanges O2 and CO2 with blood
What is Alveolar gas exchange?
—the swapping of O2 and CO2
across the respiratory membrane
Give a brief overview of what occurs during alveolar gas exchange
- Air is inhaled
- Air in alveolus comes into contact with film of water covering the alveoli
- O2 dissolves into the water and can enter the bloodstream through the respiratory membrane
What is Henry’s law?
at the air–water interface, for a given temperature, the amount of gas that
dissolves in the water is determined by its
solubility in water and its partial pressure in
air
What causes gasses to diffuse?
the difference in the pressure gradients.
The P-pressure of a dissolved gas seeks an equilibrium with that of the same gas in the alveolar air
The pressure gradient of CO2 in the blood vs alveolar air is much less than that of O2. How then are the two gasses exchanged at nearly equal rates?
CO2 is 10 times as soluble than O2 and diffuses more rapidly
What is perfusion coupling?
The ability to match air flow and blood flow to each other
O2 in the blood is found in ___ and ___ . What percentages are they found?
- Hemoglobin 98.5%
- dissolved in plasma 1.5%
Where is CO2 in transport?
- 90% is in the form of carbonic acid
- 5% is bound to proteins
- 5% is dissolved in plasma
What four factors adjust the rate of O2 unloading to match need?
- Ambient PO2
- Temp.
- Bohr effect
- concentration of (BPG)biphosphoglycerate
How does ambient PO2 adjust the rate of O2 unloading?
Active tissue has less PO2 so more O2 is released
How does the Bohr effect adjust the rate of O2 unloading?
-Bohr effect is the ambient pH’s effect on O2 loading
Active tissue has more CO2 which lowers pH causing more O2 unloading
How does temperature adjust the rate of O2 unloading?
Active tissue has higher temperatures promoting O2 unloading
How does BPG concentration adjust the rate of O2 unloading?
-RBCs produce BPG which binds to Hb; O2 is
unloaded
-increase in body temp (fever), thyroxine, growth
hormone, testosterone, and epinephrine all
raise BPG and promote O2 unloading
What is the Haldane effect?
—low level of oxyhemoglobin enables the blood to transport more CO2
What are normal arterial blood levels of pH, PCO2, and PO2?
- pH: 7.35 to 7.45
- PCO2: 40mm Hg
- PO2: 95mm Hg
Order the the stimulus that effect breathing from most potent to least
- pH
- CO2
- O2
Pulmonary ventilation is adjusted to maintain ___ of
the brain
pH
Central chemoreceptors in medulla produce about____ of
the change in respiration induced by pH shift
75%
• Hydrogen ions also stimulate peripheral
chemoreceptors which produce ___ of the
respiratory response to pH changes
25%
Acidosis is defined as ?
a blood pH lower than 7.35
Alkalosis is defined as?
a blood pH higher than 7.45
What is Hypocapnia?
PCO2 less than 37 mm Hg (normal 37
to 43 mm Hg)
• Most common cause of alkalosis
What is Hypercapnia?
—PCO2 greater than 43 mm Hg
• Most common cause of acidosis
What is a corrective homeostatic response to acidosis?
Hyperventilation
_____can be a corrective homeostatic
response to alkalosis
Hypoventilation