Part VII

Question 1

What is the goal of regulation of ventilation?

Answer 1

to keep arterial levels of CO2 and O2 constant

Question 2

The nervous system adjust the level of what to match perfusion of lungs?

Answer 2

respiratory rate and tital volume (ventilation)

Question 3

match ventilation w/ pulmonary blood flow

match ventalation with what?

Answer 3

overal metabolic demand

Question 4

Where is the dorsal repsiraotyr group located?

Answer 4

primarily in the nucleus tractus solitarius in the medulla

Question 5

Ther termination of what cranial nerves is also in the medulla?

Answer 5

CN IX and X

Question 6

What does the dorsal respiratory group receive input from?

Answer 6

peripheral chemoreceptros, baroreceptors and receptors in the lung

Question 7

What neurons are rhythmically self-excitatory?

Answer 7

dorsal respiratory group

Question 8

What muscles does the dorsal respiratory group excite?

Answer 8

muscles of inspiration

Question 9

What sets the basic drive of ventilation?

Answer 9

dorsal respiratory group

Question 10

What happens when the pneumotaxic center is inhibited?

Answer 10

it increases the duration of inspiration and increases tital volume

Question 11

Where is the pneumotaxic center located?

Answer 11

nucleus parabrachialis of upper pons

Question 12

How can the pneumotaxic center inhibit the duration of inspiration?

Answer 12

by turning off dorsal respiratory group ramp signal after the start of inspiration

Question 13

Where are the ventral respiratory groups of neurons located?

Answer 13

bilaterally in the ventral aspect of medulla oblongata

Question 14

What can the ventral respiratory group of neurons excite?

Answer 14

both inspiratory and expiratory respiratory muscles during increased ventilatory drive

Question 15

What is the function of the apneustic center?

Answer 15

functions to prevent inhibition of dorsal respiratory group under some circumstances

Question 16

Where is the apneustic center located?

Answer 16

lower pons

Question 17

Herring Breuer Inflation reflex.

Answer 17

stretch receptors located in the wall of the airways

Question 18

When are Herring stretch receptors stimulated?

Answer 18

when stretched @ tital volumes greater than 500mL

Question 19

Irritant receptors

Answer 19

among airway epithelium

Question 20

What do irritant receptors do?

Answer 20

stimulates sneezing and coughing and possibly airway consriction

Question 21

J receptors

Answer 21

alveoli next to pulmonary capillaries

Question 22

When are J receptors stimulated?

Answer 22

stimulated when pulmonary caps are engorged (pulmonary edema)

Question 23

Why is pulmonary edema bad?

Answer 23

because it makes it so theres not enough oxygen because blood isn’t pumped through fast enough and can create a feeling of dyspnea

Question 24

What are the physiologic consequences of hyperventilation?

Answer 24

decreased stroke volume and decreased coronary blood flow, repolarization of the heart is impaired, oxy-hemoglobin affinity increased, cerebral blood flow decreased, skeletal muscle spams and tetany, serum potassium decreased

Question 25

What is the common thread in most of the physiologic consequences of hyperventilation?

Answer 25

hypocapnic alkalosis

Question 26

How does brain edema effect ventilation?

Answer 26

depresses or inactivates the respiratory centers

Question 27

How do you treat brain edema?

Answer 27

intravenous hypertonic solution

Question 28

What is the most prevalent cause of respiratory depression?

Answer 28

anesthesia/narcotics

Question 29

How does exercise stimulate ventilation?

Answer 29

the increased corticospinal traffic which will collaterally stimulate respiratory centers in the brain stem

Question 30

What comes from active muscle spindles and joint proprioceptors?

Answer 30

reflex neural signals

Question 31

What stimulates local chemoreceptors when it comes to exercise?

Answer 31

fluctuations in O2 and CO2

Question 32

What is the most important adjustment in life?

Answer 32

breathing

Question 33

How is the first breath stimulated?

Answer 33

cooling of the skin, slightly asphyxiated state (increased CO2)

Question 34

How much negative pressure do babies have to get through in order to open alveoli for the first breath?

Answer 34

40-60cm H2O

Question 35

How much negative pleural pressure is needed for every other breath? (minus the first one)

Answer 35

2.5cm H2O

Question 36

What are the circulatory changes at birth?

Answer 36

placenta disconnects, TPR increases, pulmonic resistance decreases (elimination of hypoxia), closure of the foramen ovale (atrium), closure of the ductus arteriosis (great vessels), closure of ductus venosus (bypass liver)

Question 37

What are chemosensitive areas of the respiratory center stimulated by?

Answer 37

hydrogen ions and carbon dioxide

Question 38

What is the primary stimulus of chemosensitive areas of the respiratory center?

Answer 38

hydrogen ions

Question 39

Can hydrogen ions cross the BBB?

Answer 39

no

Question 40

Can carbon dioxide cross the BBB?

Answer 40

yes

Question 41

Why is there a faster increase in ventilation when there is a rise of CO2 in the CSF?

Answer 41

because there aren't buffers to prevent CO2 from coming in like there is in plasma

Question 42

chemosensitive areas of the respiratory center are unresponsive to what?

Answer 42

oxygen, it just depresses normal activity

Question 43

How much CO2 increases ventilation?

Answer 43

70-80%