Pulmonary II

Question 1

The normal automatic process of breathing originates from the

Answer 1

Brainstem

Question 2

Neurons in the ______ and ______ control the unconscious breathing

Answer 2

medulla oblongata and pons

Question 3

The _____ can override these centers if voluntary control is needed

Answer 3

Cortex

Question 4

The automatic rhythm is controlled by neurons located in the

Answer 4

medulla rhythmicity center

Question 5

Rhythm control of breathing

Answer 5

Respiratory nuclei in medulla

Question 6

Medullary rhythmicity area:

Inspiratory center

Answer 6

• Dorsal respiratory group*
• frequent signals, you inhale deeply
• signals of longer duration, breath is prolonged

Question 7

Medullary rhythmicity area:

Expiratory center

Answer 7

• Ventral respiratory group*

- involved in FORCED respiration

Question 8

Rate and depth control

Answer 8

PONS

Question 9

RESPIRATORY CENTER CONTROL:
(-) Pneumotaxic center
(in the Pons)

Answer 9

-sends continual inhibitory impulses to inspiratory center, as impulse frequency rises, breaths SHORTER, FASTER, and SHALLOWER

Question 10

RESPIRATORY CENTER
(+)Apneustic center
(in the Pons)

Answer 10

-promotes maximal lung inflation and LONG, DEEP
breaths
-inspiration & expiration

Question 11

DRG “Pacemaker”

Answer 11

in the Medula Oblongata

Question 12

Vagus nerves

Answer 12

Pulmonary stretch receptors Herring -Breur

Question 13

MEDULLA RESPIRATORY CENTER IS IN:

Answer 13

the reticular formation of the medulla beneath the floor of the fourth ventricle

Question 14

The Pre-Botzinger Complex (part of the Ventral Group)

Answer 14

is essential for generation of the respiratory rhythm.

Question 15

The Dorsal Respiratory Group (DRG)

Answer 15

sets the basic respiratory rhythm

Question 16

Ventral Respiratory Group (DRG)

Answer 16

associated with FORCED respiration

Question 17

Factors Affecting Airway Resistance

Answer 17

• Diameter of airway
• Flow (Laminar vs. Turbulent)
• Density of Gas (viscosity)
• Goverened by Poiseuille’s Law

V= P r4/8

Question 18

PNEUMOTAXIC CENTER IN THE upper PONS

Answer 18

• Inhibits inspiration*
• limits the burst of action potentials in the phrenic nerve, effectively decrease the tidal volume and regulating the respiratory rate
• “Fine-tuning” of respiratory rhythm because normal rhythm can exist in the absence of this center

Question 19

APNEUSTIC CENTER IN THE lower PONS

Answer 19

• Promotes inspiration*
• Excitatory effect on the Dorsal Respiratory Group in the medulla
• Sends signals to the Dorsal Respiratory Group in the medulla to delay the “switch off” signal provided by the pneumotaxic center

Question 20

EXPIRATION OCCURS DUE TO:

Answer 20

elastic recoil of lung tissues and chest wall

Question 21

Impulses from the Vagus (X) and Glossopharyngeal (IX) nerves _________ the output of inspiratory cells

Answer 21

modulate

Question 22

T/F Dorsal and Ventral Respiratory Groups’ cells, even when all afferent stimuli is abolished, these cells generate repetitive action potentials that send impulses to the diaphragm and other respiratory muscles

Answer 22

True

Question 23

Input to Respiratory Centers from limbic system and hypothalamus

Answer 23

-resp effects of pain and emotion

Question 24

Input to Respiratory Centers from chemoreceptors

Answer 24

-monitor blood pH, CO2 and O2 levels

Question 25

RATE AND DEPTH OF BREATHING ADJUSTED TO MAINTAIN LEVELS OF:

Answer 25

- pH - Pco2 - Po2

Question 26

what can exist in absence of pneumotaxic center

Answer 26

-"Fine tuning" of respiratory rhythm because a normal rhythm can exist in the absence of this center

Question 27

PRIMARY STIMULUS FOR CENTRAL CHEMORECEPTORS

Answer 27

pH of CSF

Question 28

Co2 easily crosses the

Answer 28

BBB

Question 29

HYPERCAPNIA

Answer 29

Pco2> 45mmHg

Question 30

in CSF the CO2 reacts with water and releases

Answer 30

H+

Question 31

the cycle of inspiration:

Answer 31

-Latent period of several seconds - -Crescendo of action potentials leading to a ramp of strengthening inspiratory muscles - -Inspiration action potentials cease and inspiratory muscle tone falls - -Expiration occurs due to elastic recoil of lung tissues and chest wall

Question 32

central chemoreceptors strongly stimulate

Answer 32

inspiratory center

Question 33

"blowing off" CO2 pushes reaction to the

Answer 33

left

Question 34

RESPIRATORY ALKALOSIS

Answer 34

(PH>7.4)

Question 35

hypocapnia

Answer 35

Pco2 < 35mmHg

Question 36

hypoventilation (increases Co2) pushes reaction to the

Answer 36

right

Question 37

ketoacidosis may be compensated for by _____ respirations

Answer 37

Kussmaul

Question 38

peripheral chemoreceptors

Answer 38

``` -found in major blood vessels >AORTIC BODIES - (signals medulla via C.N. X) >CAROTID BODIES - (signal medulla by C.N. IX) ```

Question 39

CENTRAL CHEMORECEPTORS

Answer 39

-in medulla >primarily monitor pH of CSF >↑H+ stimulates ventilation >↓H+ inhibits it

Question 40

central chemoreceptors mediate ___ % of ventilatory respons

Answer 40

80%

Question 41

peripheral chemoreceptors mediate ____ % of ventilatory response

Answer 41

20%

Question 42

NORMAL PH OF CSF

Answer 42

7.33

Question 43

CSF has much less buffering capacity compared to blood, resulting in:

Answer 43

greater change in pH with changes in PCO2

Question 44

With _______ disease, the hypoxic drive to ventilation becomes very important

Answer 44

severe lung disease

Question 45

IF A HIGH 02 MIXTURE IS GIVEN TO RELIEVE HYPOXEMIA...

Answer 45

The ventilation may be grossly depressed