Core Organ Functions: A&P The Respiratory System

Question 1

What is the main muscle of ventilation?

Answer 1

The diaphragm

Question 2

The most important expiratory accessory muscles

Answer 2

the abdominal muscles

Question 3

The most important inspiratory accessory muscles

Answer 3

The cervical strap muscles

the scalenes help prevent inward motion of the ribs
the SCMs help to elevate the upper part of the rib cage

Question 4

Lung anatomy: what is the point at which cartilate is totally absent from the airway wall?

Answer 4

The terminal bronchiole

Question 5

The functional unit of the lung. it comprises of respiratory bronchioles, alveolar ducts, alveolar sacs, and grape-like clusters of alveoli.

Answer 5

The acinus

Question 6

these types of cells form the majority of the epithelial surface of the alveolus

Answer 6

Type I cells

Question 7

These types of cells produce surfactant and fuction as reserve precursor cells for type I cells

Answer 7

Type II cells

Question 8

What are the two types of vascular supply for the pulmonary system?

Answer 8

1. Bronchial: Arises from the aorta and the intercostal arteries, and is oxygenated systemic blood that provides nutrition to the tissues of the bronchi, visceral pleura, and pulmonary vasculature. NOT INVOLVED IN ALVEOLAR GAS EXCHANGE.
2. Pulmonary: take deoxygenated sytemic blood and sends it to the pulmonary capillaries for interface with the alveoli

Question 9

The movement of lung tissue depends on overcoming what 2 types of resistance?

Answer 9

1. Elastic resistance of the lung parenchyma, chest wall, and gas-liquid interface in the alveoli
2. Nonelastic resistance of the airways to gas flow.

Question 10

What is the name of the work necessary to overcome elastic and non-eleastic resistance in the lungs?

Answer 10

The physiologic work of breathing

Question 11

What is LaPlace’s law?

Answer 11

Pressure = (2 x surface tension) / Radius

-It helps to quantify the pressure within the alveolus with a given surface tension.
-The higher the surface tension, the greater the propensity of the alveolus to collapse.

Question 12

This substance reduces surface tension, allowing the alveolus to more readily stay expanded

Answer 12

Surfactant

Question 13

What is the formula for compliance?

Answer 13

Compliance = delta C/ delta P

The higher the pressure needed to produce a specific change in volume, the lower the compliance of the system and the higher is the elastic recoil of that same system.

Question 14

What is Compliance affected by?

Answer 14

The presence of secretions, inflammation, fibrosis, fluid overload, etc

Question 15

During laminar flow, what is the velocity of gas in the cylinder abutting the tube walls?

Answer 15

Zero

Question 16

During laminar flow, where is the maximal flow velocity located?

Answer 16

in the innermos cylinder

Question 17

What is the formula for resistance to laminar flow?

Answer 17

R = (8 x length x velocity) / (Pi x (radius)^4 flow) = Pb - Pa

Pb = barometric pressure
Pa = alveolar pressure

-Airway radius influences resistance by a power of 4.
-Gas density has no effect on resistance to laminar flow; only viscoscity influences resistance
-Less dense gases such as helium will not improve gas flow in the setting of laminar flow.

Question 18

Random movements of gas through a tube created by flow through branched or disordered tubes resulting in a disruption of laminar flow

Answer 18

Turbulent flow

Question 19

The resistance during turbulent flow is generally proportinal to?

Answer 19

The flow rate of the gas.

Question 20

Turbulent flow is _____ sensitive to a change in radius

Answer 20

exquisitely more

A change in radius results in a change in resistance to a power of 5 of the change in radius

Question 21

Resistance to turbulent flow is ______ proportional to gas density rater than viscosity

Answer 21

directly

As gas density decreases, resistance decreases as well

Question 22

The ______ contains the most basic ventilation control centers, the dorsal respiratory group (DRG) and the ventral respiratory group (VRG).

Answer 22

medula oblongata

Question 23

The _____ provides for a ventilation rate by rhythmically stimulating inspiration.

Answer 23

DRG

Question 24

The ____ coordinates expiration

Answer 24

VRG

Question 25

The ____________ communicate with respiratory centers in the medulla oblongata to alter the ventilation pattern and rate

Answer 25

Pontine respiratory centers (apneustic and pneumotaxic)

Question 26

The ________ center sends siganls to the DRG to prolong respiration, whereas the _____ center functions to limit inspiration.

Answer 26

aneustic
pneumotaxic (will also increase the ventilatory rate and decrease inspiratory volume with increased stimulation)

Question 27

The primary centers of ventilation control.

Answer 27

respiratory centers in the medulla and pons.

The midbrain and cerebral cortex may also affect the ventilatory pattern, in addition to relexes (swallowing, cough, and vomiting)

Question 28

___________ in the airways of the lungs likely react to pressure changes from pulmonary edema or atelectasis, providing proprioception for the lungs and resulting in ventilatory alterations

Answer 28

Smooth muscle spindles

Question 29

_____________________, tendon spindles primarily located in intercostal muscles, are stimulated when stretched, inhibiting further inspiration

Answer 29

Golgi tendon orgams

Question 30

The __________________________ reflex, may also alter ventilation by inhibiting inspiration during lung distension.

Answer 30

Hering-Breuer

Question 31

Central chemoreceptors are located in the _____ and relay information on ventilation needs based on ____

Answer 31

medulla
pH

Question 32

Signaling to the respiratory centers is initiated at arterial partial pressure of oxygen < _____ mmHg

ventilation is not altered until oxyen partial pressure falls below ___ mmHg, at which point tidal volume and ventilation rate are increased

Answer 32

100

65

Question 33

Deliver signals to the respiratory centers based on oxygen and carbon dioxide content from the periphery

Answer 33

carotid body chemoreceptors

Question 34

Where are the carotid body chemoreceptors found?

Answer 34

at the bifurcation of the common carotid artery

Question 35

How do the carotid body chemoreceptors communicate with respiratory centers?

Answer 35

via glossopharyngeal nerve

Question 36

Peripheral carotid body chemoreceptors respond primarily to _____, while central chemoreceptors react to ________________.

Answer 36

lack of oxygen

elevations in carbon dioxide.

Question 37

Delivers signals regarding partial pressure of oxygen via the vagus nerve, leading primarily to changes in circulation with minimal effect on ventilation

Answer 37

Aortic body chemoreceptors (found in the aortic arch)

Question 38

Describe what happens to your carbon dioxide and oxygen levels during:

-significant altitude elevation
-breath holding

Question 39

Explain how the ventilatory response changes for a given PaCO2 in the following settings:
-Normal
-Hypoxemic/metabolic acidosis
-Opioids/barbiturates
-anesthesia/prolonged anesthesia

Question 40

Why is oxgen at supratherapeutic levels detrimental?

Answer 40

1. Suppresses ventilation resulting in hypercarbia for PO2 levels 65mmHg in patients who depend on peripheral chemoreceptors for hypoxic ventilatory drive
2. Free radical injury, resulting in acute lung injury

Question 41

Relative concentrations of oxygen drive the movement of oxygen into the blood, allowing for oxygentation in the absence of ventilation, provided that a diffusion gradient is present.

Answer 41

Apneic oxygenation

Question 42

The pulmonary diffusion capacity or the ability of carbon dioxide to pass between the alveoli to blood is __ times greater than oxygen, allowing for it to diffuse across the alveolar membrane with greater efficiency.

Answer 42

20

Question 43

Explain the oxygen-hemoglobin dissociation curve

Question 44

What is the Bohr effect vs. the Haldane effect?

Answer 44

The Bohr effect specifically describes hemoglobin’s decreased affinity for oxygen in environments with carbon dioxide elevation or acidosis

the haldane effect is the ability of deoxygenated hemoglobin to transport carbon dioxide by facilitating the formation of bicarbonate and acting as a buffer for formed hydrogen ions and a carboamino compound.

Question 45

Ten percent of carbon dioxide in blood is ______, and the bulk of carbon dioxide is transported and stored as _______.

Answer 45

dissolved

bicarbonate

Question 46

Ventilation distribution within the lungs depends on ___________ and ________________.

Answer 46

compliance of the alveoli

relative distending pressure.

Question 47

In an upright patient, which part of the lungs are exposed to greater ventilation during inspiration?

Answer 47

The basal alveoli because they are relatively less inflated vs. the apical alveoli but are resting at a more compliant position with a greater distending pressure. The apical alveoli are resting at larger inflated volumes vs. the basal alveoli because of the greater complressing gravatational pressure outside the alveoli at the base.

During spontaneous ventilation, more gas is distributed to gravity-dependent areas.

Question 48

Describe the West zone’s

Answer 48

Apex: Zone 1: PA>Pa>Pv
Zone 2: Pa>PA>Pv
Base: Zone 3: Pa>Pv>PA

Question 49

Both ventilation and perfusion of alveoli increase at the ____ compared with the ___, but the rate of increase is greater for ______ than for _________.

Answer 49

Base

Apex

Perfusion

Ventilation

Question 50

Ventilation in the excess of perfusion

What does it primarily alter?

Answer 50

Dead space

CO2 elimination