Exam 4: Respiratory L1 Flashcards
What is the primary function of the respiratory system?
Primary function of the respiratory system is gas exchange (O2 in and CO2 out)
What are the steps of external respiration?
What happens during internal respiration?
External respiration: exchange of air in lungs and O2 and CO2 exchanged in alveoli
Internal Respiration: mitochondria consume O2 and produce CO2
What structures comprise the upper airway?
Lower airway?
Upper airway: nose, pharynx, glottis, vocal chords
Lower airway: trachae, bronchial tree, alveoli
What are the major functions of the upper airway?
Major Functions of the Upper Airway:
- Filter (nose filters out particles greater than 10 um)
- “condition inspired air” : increase temp and humidify the air
What are three mechanisms for bypassing the upper airway?
Ways to bypass the upper airway:
Intubation
Tracheostomy (long-term)
Cricothyroidoyomy “cric”
What happens when we bypass the upper airway?
When the upper airway is bypasses, we lose upper airway functions like humification of air
How many lobes are in the right lung vs the left lung?
Right lung: 3 lobes
Left lung: 2 lobes
Explain parietal pleura and visceral pleura
Parietal pleura: outer wall that contains capillaries that release pleural fluid, and stomata and lymphatics that drain that fluid
Visceral pleura: inner wall
Pleural space is space between the two, and there is NO AIR in the pleural space normally
Pleural fluid:
Primary function?
How much?
Space is _______ (_____ pressure)
Low/high protein content
Pleural fluid:
Primary function: lubricant
10-20 mLs
Space is subatmospheric (negative pressure)
Low protein ( < 1.5 g/dL)
- protein content is critical for clinical diagnosis
(high protein means inflammatory…. low protein means hydrostatic/oncotic balance)
Define pleural effusion
Pleural effusion is excess fluid in the pleural space
(pulmonary edema is a general term for fluid in the lungs, where as pleural effusion is more spefically describing fluid in the pleural space)
Explain the anatomy of the trachae (and the function of each section)
Trachae: have a c shaped cartilage ring, with a smooth muscle section
The cartilage maintains the structure and protects the airway
The smooth muscle helps with constriction and flexibility
Just like the ___ side of the lungs is slightly larger, the _____ mainstem bronchus is also larger
Inhaled foreign bodies are more commonly lodged in the _____ lung
Just like the right side of the lungs is slightly larger, the right mainstem bronchus is also larger in diameter
Inhaled foreign bodies are found more commonly in the right side of the lungs
The base of the trachae is called the _____
Base of trachae is called the “carina”
gets structurally damaged in smokers
Explain the primary, secondary, and tertiary sections of the bronchi
Main bronchi > lobar bronchi (secondary) > segmental bronchi (tertiary)
Segmental bronchi:
10 in right lung
8-10 in left lung
can remove one with minimal effect on the others
What is the functional anatomic unit of the lower airway?
Functional anatomic unit: bronchopulmonary segment
The trachea is part of the _____ airway
Trachae is part of lower airway
What is the difference between the bronchi and bronchioles
Difference between bronchi and bronchioles is that bronchi contain cartilage and broncioles do not
Explain the segments that count as “conducting airways” vs “respiratory units”
Conducting zone: trachea, bronchi, nonrespiratory bronchioles
Res[piratory zone: respiratory bronchioles and alveoli
Respiratory Unit:
contains______
Volume
Surface Area
Respiratory unit is respiratory broncioles and alveoli
volume: 2500 mL
Surface area of seventy square meters or 750 sq ft
Most of the cross sectional area within the respiratory system is within the ____
LARGE cross sectional area of the respiratory zone
Alveoli:
Type I cells vs Type II cells
What are alveolar macrophages?
Alveoli:
Type I: where gas exchange happens (95-98% of surface area)
Type II cells: produce surfactant (2-4% of surface area)
What are the secondary functions of the alveoli?
Secondary functions of the alveoli:
Barrier functions
Immune functions
Alveolar surface tension is due to _____
What is the eqn given by law of laplace and what does it say about smaller bubbles vs larger bubbles?
Surface tension in alveolar is caused by H20 molecules being attracted to one another
Law of Laplace: Inward Pressure= 2 x Surface Tension/ Radius of the bubble
This equation suggests that the small bubbles would collapse and the larger bubbles would become distended
This does not happen physiologically
Stability of Alveoli:
Alveoli do not collapse like the Law of Laplace would suggest because:
1.
2.
Alveoli do not collapse because:
- Surfactant
- Interdependence
Surfactant:
Produced by ______ cells
Made up of ______
It ____ surface tension
Surfactant is produced by Type II alveolar cells
Surfactant is a lipoprotein complex (made up of phospholipids)
Surfactant reduces surface tension and stabilizes alveoli
Explain Infant Respiratory Distress Syndrome
Most commonly from _____
Treatment?
Infant Respiratory Distress Syndrome:
- Most commonly from premature delivery
- Type II cells differentiate and produce surfactant after week 24, with normal surfactant levels at week 35
- Treatment: steroids pre-birth to increase Type 2 differentiation, external surfactant for infants
Stability of Alveoli:
Interdependence:
Explain how alveoli are mechanically tethered
Explain “collateral ventilation”
Tendency of alveoli to collapse is opposed by the traction to excerted by the surrounding the neighbor alveoli
Collateral Ventilation: “MLK”, channels of martin, channels of lambert, pores of kohn (makes sure air flows in uniformly by having channels and pores for it to flow through)
What are the two vascular systems that supply blood to the lungs?
Bronchial circulation (systemic)
Pulmonary circulation
Bronchial Circulation:
Explain bronchial arteries
Bronchiole Arteries:
- from aorta to terminal bronchioles
- merge with pulmonary arteries and capillaries
- 1-2 % of total cardiac output
Explain bronchial veins:
1/3 of the blood goes to ___
2/3 of the blood goes to __
Bronchial Veins:
1/3 of blood returns to right heart
2/3 of blood drains into pulmonary circulation (causing a mixture of deoxy and oxy blood)… contributes to venous admixture of anatomic shunt
Explain the pulmonary circulation
primary purpose
vascular area
capillary volume
Pulmonary circulation:
Near 100% of right heart output
Primary purpose to deliver blood to lung for gas exchange
Largest vascular bed in the body (70 meters squared)
Capillary volume- at rest is 70mL, during exercise is 200mL
Because 100% of right cardiac output goes to the lungs, it is the hotspot for _____
Because 100% of right cardiac output goes to the lungs, they are a hotspot for modifying/removing components of the blood
Pulmonary endothelia express many enzymes and transporters
Explain the deposition of inhaled material:
Where does impaction, sedementation and diffusion happen?
Explain the clearance of inhaled particles within the bronchi vs within the alveoli
Clearance of inhaled particles:
nasopharynx: particles swallowed
Bronchi: mucociliary system
Alveoli: alveolar macrophages engulf particles
What are the three components of the mucociliary clearance system?
Three components of the mucociliary clearance system: mucous layer, periciliary fluid, cilia
Explain the mucociliary clearance system?
What kind of cytoskeletal parts play a role?
Mucociliary Clearance System:
Highly organized microtubule cytoskeleton and dynein motors drive ciliary “beating”
Humidity impacts both ______ & _______
Humidity impacts both virus containing particles and mucociliary clearance
Low humidity leads to an ______ in stable virus that is _________
Low humidity leads to an increase in stable virus that is more capable of making it to its favorite cellular receptor (example, the COVID 19 receptor is thought to be ACE 2 which is very deep within the respiratory system)
Cilia stall in dry cold air because:
dry air _____ the mucous layer
cold ____ ciliary function
Cilia stall in dry cold air because:
dry air dehydrates the mucous layer
cold inhibits ciliary function
Increasing humidity from 20% to 50% will ____ mucociliary clearance
Increasing humidity increases mucociliary clearance (think about WHY people put humidifiers in their room)
Upper airways ____, ___, and _____ air
Airways are divided into two zones:
Volume of the anatomic dead space is ___
Upper airways filter, warm, and humidify air
Airways are divided into two zones : conducting zone (down to terminal bronchioles) and a respiratory zone
Volume of anatomic dead space is 150 mL
Volume of the respiratory region is ____
The ______ segment is the functional anatomic unit, whereas the _____ is the basic physiological unit
The alveolar capillary network is extremely ___, ideal for gas exchange
Volume of the respiratory region is 2.5-3 L, surface area of 50-100 meters squared
The broncho-pulmonary segment is the functional anatomical unit, whereas the respiratory segment (respiratory bronchi and alveolar ducts) is the basic physiological unit
The alveolar capillary network is extremely thin, idea for gas exchange
_______, _______, and _____ stabilize alveoli
The lung has 2 circulations: _____ and _____
Surfactant (reduction of surface tension), interdependence, and collateral ventilation stabilize alveoli
The lung has two circulations: bronchial (systemic) and pulmonary
The _______ has the largest vascular bed in the body
The lung has also metabolic functions (convertion of ____ into _____)
The mucociliary transport system removes inhaled particles (humidity impacts both ___ and ___)
The pulmonary circulation is the largest vascular bed in the body
The lung also has metabolic functions (conversion of AngI to AngII by ACE)
The mucociliary transport system removes inhaled particles (humidity impacts both virus-containing droplets AND mucociliary clearance)
Air flows _________ a pressure gradient (from ___ to ___)
Explain inspiration vs expiration in terms of pressure and air flow
Air flows DOWN a pressure gradient (from high pressure to lower pressure)
Inspiration: alveolar pressure is lower than atmospheric pressure (air flows in)
Expiration: alveolar pressure is above atmospheric pressure (air flows out)
Explain how boyle’s law relates to breathing?
Boyle’s law: pressure and volume of a gas are inversely proprotional to one another
P1V1 = P2V2
If volume goes down, pressure increases, etc
What are the Major muscles of inspiration?
Accessory muscles of inspiration?
Major Muscles of Inspiration: diaphragm and external intercostal muscles
Accessory muscles: sternocleidomastoid and scalenus
______ & ______ contract with every inspiration
Diaphragm and external intercostals contract with every inspiration
Intercostals: label which helps with inhaling vs exhaling
External :
Internal:
External Intercostals: inhaling
Internal intercostals: expiration
The major inspiratory muscles are the ___ and the ___
The diaphragm:
- is stimulated by the ____ nerve
- accounts for _____ increase in thorax cavity volume
- stimulation causes ____
External Intercostal Muscles:
- are stimulated by _____ nerves
- Stimulation causes___
Major inhale muscles: diaphragm & external intercostals
Diaphragm:
- stimulated by the phrenic nerve
- accounts for 75% increase in thoracic cavity
- stimulation causes muscle to flatten/contract/move downward, which enlarges the cavity in a vertical way
External Intercostal Muscles:
- stimulated by the intercostal nerves
- stimulation causes ribs to move up and outward, enlarges cavity laterally and anteroposterior direction
Diaphragm contraction lowers the floor of the thoracic cavity, thus increasing the volume of the thoracic cavity, and ____ the pressure
Increasing the volume and therefore lowering the pressure
Inspiration:
Contraction of the _____ moves the rib cage out and up
Similar to moving the handle on a bucket
Contraction of the external intercostal muscles moves the rib cage up and out.
Similar to moving the handle on a bucket
Deep Forceful Inspiration:
Occurs via the acessory inspiratory muscles
Contraction of neck muscles: ___ and ___
Enlarges the thorax
Nasal muscles can also be activated
Deep Forceful Inspiration:
Occurs via accessory muscles
Contraction of neck muscles: scalenus and sternocleidomastoid raise the sternum and elevates the first two ribs
These are only used during forceful inspiration such as exercise or trouble breathing
Nasal muscles can also be activated
Expiration is mostly _____
Diaphragm relazation allows____
________ muscles relax, causing the rib cage to__
Lungs deflate and thorax compressues due to ___
Expiration is mostly passive
Diaphragm relaxation allows muscle to assume its natural dome shape
Intercostal muscles relax, causing rib cage to fall down due to gravity
Lungs deflate and thorax compresses due to natural recoil
What does forced expiration require?
_____ contraction increases pressure and pushes diaphragm upward
______ contraction flattens the rib cage by pulling the ribs downward and inward
Forced Expiration requires contraction of expiratory muscles
Abdominal muscle contraction increases abdominal pressure and pushes the diaphragm upward
Internal Intercostal muscles contraction flatten the rib cage by pulling the ribs down and in
How do intercostal muscles connecting the same ribs have opposing effects?
Direction of contraction and flexibility
What determines the volume of air in the lungs?
The serous fluid within intra-pleural space has a total volume of ____
Lung-chest wall interactions determines volume of air in lungs. Lung and chest wall move together as a unit: they have the same volume changes.
The serous fluid within intra-pleural space has a total volume of 10-20mL distributed over entire surface of the lung (very thin)
During quiet breathing, the lung and chest wall are ___
During quiet breathing, the lung and chest wall are pulling away from one another, thus creating negative pressure in the pleural space
Explain traumatic pneumothorax vs spontaneous pneumothorax
What is the treatment for pneumothorax?
Traumatic pneumothorax: puncture wound in chest wall
Spontanoues penumothorax: hole in lung
Both instances, the pleural space equilibrates to the pressure in the atmosphere and collapses the lung volume
Treatment for pneumothorax: for mild ones it’s observation and manual aspiration…for more severe ones it’s chest tube or under water seal drain
Pressure volume gradients during a tidal volume breath
Intrapleural pressure is always ____
Lungs are always ___
At end inspiration and end exhalation____
DRAW THE GRAPHS for inspiration and expiration of volume, pleural pressure, flow, and alveolar pressure
Interpleural pressure is always below atmosphere (in tidal breathing)
Lungs are always stretched to some degree, even during expiration
At end inspiration and end exhalation, alveolar pressure is the same as atmospheric
Air flows in/out the airways through _____
Inspiration is ___, whereas expiration is ___
___ is most important muscle of respiration
___ are used during forced inhalation/exhalation
Lung volumes are determined by the ____
When there is no air flow, inward recoild of the lung and outward recoild of chest wall are ___, pressure across entire system is __
Air flows in/out of airways through pressure gradients
Inspiration is active, exhalation is passive
Diaphragm is most important muscle of respiration
Accessory muscles are used during forced inhalation and exhalation
Lung volumes are determined by the balance between the elastic revoil of the lung and the properties of the chest wall/muscles
When there is no air flow, inward recoild of the lung and outward recoild of the chest wall are balanced, pressure across the entire system is 0 (this happens at end of inspiration and expiration)
Conducting zone vs respiratory zone:
Air moves in conducting zone by_____
Air moves in respiratory zone by ___
Conducting zone: air moves by convection/bulk flow
Respiratory zone: air moves by diffusion
