Exam 4: Respiratory L1

Question 1

What is the primary function of the respiratory system?

Answer 1

Primary function of the respiratory system is gas exchange (O2 in and CO2 out)

Question 2

What are the steps of external respiration?

What happens during internal respiration?

Answer 2

External respiration: exchange of air in lungs and O2 and CO2 exchanged in alveoli

Internal Respiration: mitochondria consume O2 and produce CO2

Question 3

What structures comprise the upper airway?

Lower airway?

Answer 3

Upper airway: nose, pharynx, glottis, vocal chords

Lower airway: trachae, bronchial tree, alveoli

Question 4

What are the major functions of the upper airway?

Answer 4

Major Functions of the Upper Airway:

1. Filter (nose filters out particles greater than 10 um)
2. “condition inspired air” : increase temp and humidify the air

Question 5

What are three mechanisms for bypassing the upper airway?

Answer 5

Ways to bypass the upper airway:

Intubation

Tracheostomy (long-term)

Cricothyroidoyomy “cric”

Question 6

What happens when we bypass the upper airway?

Answer 6

When the upper airway is bypasses, we lose upper airway functions like humification of air

Question 7

How many lobes are in the right lung vs the left lung?

Answer 7

Right lung: 3 lobes

Left lung: 2 lobes

Question 8

Explain parietal pleura and visceral pleura

Answer 8

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

Question 9

Pleural fluid:

Primary function?

How much?

Space is _______ (_____ pressure)

Low/high protein content

Answer 9

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)

Question 10

Define pleural effusion

Answer 10

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)

Question 11

Explain the anatomy of the trachae (and the function of each section)

Answer 11

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

Question 12

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

Answer 12

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

Question 13

The base of the trachae is called the _____

Answer 13

Base of trachae is called the “carina”

gets structurally damaged in smokers

Question 14

Explain the primary, secondary, and tertiary sections of the bronchi

Answer 14

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

Question 15

What is the functional anatomic unit of the lower airway?

Answer 15

Functional anatomic unit: bronchopulmonary segment

Question 16

The trachea is part of the _____ airway

Answer 16

Trachae is part of lower airway

Question 17

What is the difference between the bronchi and bronchioles

Answer 17

Difference between bronchi and bronchioles is that bronchi contain cartilage and broncioles do not

Question 18

Explain the segments that count as “conducting airways” vs “respiratory units”

Answer 18

Conducting zone: trachea, bronchi, nonrespiratory bronchioles

Res[piratory zone: respiratory bronchioles and alveoli

Question 19

Respiratory Unit:

contains______

Volume

Surface Area

Answer 19

Respiratory unit is respiratory broncioles and alveoli

volume: 2500 mL

Surface area of seventy square meters or 750 sq ft

Question 20

Most of the cross sectional area within the respiratory system is within the ____

Answer 20

LARGE cross sectional area of the respiratory zone

Question 21

Alveoli:

Type I cells vs Type II cells

What are alveolar macrophages?

Answer 21

Alveoli:

Type I: where gas exchange happens (95-98% of surface area)

Type II cells: produce surfactant (2-4% of surface area)

Question 22

What are the secondary functions of the alveoli?

Answer 22

Secondary functions of the alveoli:

Barrier functions

Immune functions

Question 23

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?

Answer 23

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

Question 24

Stability of Alveoli:

Alveoli do not collapse like the Law of Laplace would suggest because:

1.

2.

Answer 24

Alveoli do not collapse because:

1. Surfactant
2. Interdependence

Question 25

Surfactant: Produced by ______ cells Made up of \_\_\_\_\_\_ It ____ surface tension

Answer 25

Surfactant is produced by Type II alveolar cells Surfactant is a lipoprotein complex (made up of phospholipids) Surfactant reduces surface tension and stabilizes alveoli

Question 26

Explain Infant Respiratory Distress Syndrome Most commonly from \_\_\_\_\_ Treatment?

Answer 26

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

Question 27

Stability of Alveoli: Interdependence: Explain how alveoli are mechanically tethered Explain "collateral ventilation"

Answer 27

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)

Question 28

What are the two vascular systems that supply blood to the lungs?

Answer 28

Bronchial circulation (systemic) Pulmonary circulation

Question 29

Bronchial Circulation: Explain bronchial arteries

Answer 29

Bronchiole Arteries: - from aorta to terminal bronchioles - merge with pulmonary arteries and capillaries - 1-2 % of total cardiac output

Question 30

Explain bronchial veins: 1/3 of the blood goes to \_\_\_ 2/3 of the blood goes to \_\_

Answer 30

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

Question 31

Explain the pulmonary circulation primary purpose vascular area capillary volume

Answer 31

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

Question 32

Because 100% of right cardiac output goes to the lungs, it is the hotspot for \_\_\_\_\_

Answer 32

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

Question 33

Explain the deposition of inhaled material: Where does impaction, sedementation and diffusion happen?

Answer 33

Question 34

Explain the clearance of inhaled particles within the bronchi vs within the alveoli

Answer 34

Clearance of inhaled particles: nasopharynx: particles swallowed Bronchi: mucociliary system Alveoli: alveolar macrophages engulf particles

Question 35

What are the three components of the mucociliary clearance system?

Answer 35

Three components of the mucociliary clearance system: mucous layer, periciliary fluid, cilia

Question 36

Explain the mucociliary clearance system? What kind of cytoskeletal parts play a role?

Answer 36

Mucociliary Clearance System: Highly organized microtubule cytoskeleton and dynein motors drive ciliary "beating"

Question 37

Humidity impacts both ______ & \_\_\_\_\_\_\_

Answer 37

Humidity impacts both virus containing particles and mucociliary clearance

Question 38

Low humidity leads to an ______ in stable virus that is \_\_\_\_\_\_\_\_\_

Answer 38

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)

Question 39

Cilia stall in dry cold air because: dry air _____ the mucous layer cold ____ ciliary function

Answer 39

Cilia stall in dry cold air because: dry air dehydrates the mucous layer cold inhibits ciliary function

Question 40

Increasing humidity from 20% to 50% will ____ mucociliary clearance

Answer 40

Increasing humidity increases mucociliary clearance (think about WHY people put humidifiers in their room)

Question 41

Upper airways \_\_\_\_, \_\_\_, and _____ air Airways are divided into two zones: Volume of the anatomic dead space is \_\_\_

Answer 41

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

Question 42

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

Answer 42

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

Question 43

\_\_\_\_\_\_\_, \_\_\_\_\_\_\_, and _____ stabilize alveoli The lung has 2 circulations: _____ and \_\_\_\_\_

Answer 43

Surfactant (reduction of surface tension), interdependence, and collateral ventilation stabilize alveoli The lung has two circulations: bronchial (systemic) and pulmonary

Question 44

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 \_\_\_)

Answer 44

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)

Question 45

Air flows _________ a pressure gradient (from ___ to \_\_\_) Explain inspiration vs expiration in terms of pressure and air flow

Answer 45

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)

Question 46

Explain how boyle's law relates to breathing?

Answer 46

Boyle's law: pressure and volume of a gas are inversely proprotional to one another P1V1 = P2V2 If volume goes down, pressure increases, etc

Question 47

What are the Major muscles of inspiration? Accessory muscles of inspiration?

Answer 47

Major Muscles of Inspiration: diaphragm and external intercostal muscles Accessory muscles: sternocleidomastoid and scalenus

Question 48

\_\_\_\_\_\_ & ______ contract with every inspiration

Answer 48

Diaphragm and external intercostals contract with every inspiration

Question 49

Intercostals: label which helps with inhaling vs exhaling External : Internal:

Answer 49

External Intercostals: inhaling Internal intercostals: expiration

Question 50

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\_\_\_

Answer 50

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

Question 51

Diaphragm contraction lowers the floor of the thoracic cavity, thus increasing the volume of the thoracic cavity, and ____ the pressure

Answer 51

Increasing the volume and therefore lowering the pressure

Question 52

Inspiration: Contraction of the _____ moves the rib cage out and up Similar to moving the handle on a bucket

Answer 52

Contraction of the external intercostal muscles moves the rib cage up and out. Similar to moving the handle on a bucket

Question 53

Deep Forceful Inspiration: Occurs via the acessory inspiratory muscles Contraction of neck muscles: ___ and \_\_\_ Enlarges the thorax Nasal muscles can also be activated

Answer 53

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

Question 54

Expiration is mostly \_\_\_\_\_ Diaphragm relazation allows\_\_\_\_ \_\_\_\_\_\_\_\_ muscles relax, causing the rib cage to\_\_ Lungs deflate and thorax compressues due to \_\_\_

Answer 54

Expiration is mostly passive **Diaphragm relaxation** allows muscle to assume its natural dome shape I**ntercostal muscles relax**, causing rib cage to fall down due to gravity Lungs deflate and thorax compresses due to **natural recoil**

Question 55

What does forced expiration require? \_\_\_\_\_ contraction increases pressure and pushes diaphragm upward \_\_\_\_\_\_ contraction flattens the rib cage by pulling the ribs downward and inward

Answer 55

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

Question 56

How do intercostal muscles connecting the same ribs have opposing effects?

Answer 56

Direction of contraction and flexibility

Question 57

What determines the volume of air in the lungs? The serous fluid within intra-pleural space has a total volume of \_\_\_\_

Answer 57

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)

Question 58

During quiet breathing, the lung and chest wall are \_\_\_

Answer 58

During quiet breathing, the lung and chest wall are pulling away from one another, thus creating negative pressure in the pleural space

Question 59

Explain traumatic pneumothorax vs spontaneous pneumothorax What is the treatment for pneumothorax?

Answer 59

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

Question 60

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

Answer 60

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

Question 61

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 \_\_

Answer 61

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)

Question 62

Conducting zone vs respiratory zone: Air moves in conducting zone by\_\_\_\_\_ Air moves in respiratory zone by \_\_\_

Answer 62

Conducting zone: air moves by convection/bulk flow Respiratory zone: air moves by diffusion