Lecture 5: Control Breathing

Question 1

what are the 3 elements that control the respiratory system? What are their functions?

Answer 1

1. sensors that gather info
2. central controller in the brain that coordinates info and sends impulses
3. effectors (respiratory muscles) receive impulses and affect ventilation

Question 2

what structures are the sensors of the respiratory system?

Answer 2

chemoreceptors and other other lung receptors

Question 3

what brain structures are the central control of breathing?

Answer 3

pons, medulla and other parts

Question 4

what are the pontine respiratory structures (in the pons)

Answer 4

pneumotaxic area and the apneustic area

Question 5

what are the medullary respiratory structures?

Answer 5

1. pre-botzinger complex
2. ventral respiratory group
3. dorsal respiratory group

Question 6

diaphragm and intercostal muscles require ____ to inititate inspirations

Answer 6

stimulation by motor nerves

Question 7

the destruction of motor nerves feeding the inspiratory muscles would lead to ___

Answer 7

paralysis of respiratory muscles and death

Question 8

give an example of a disease that causes damage to nerves feeding the respiratory muscles

Answer 8

poliomyelitits

Question 9

the diaphragm is innervated by the ___ nerve

Answer 9

phrenic

Question 10

what brain structure sends signals to muscles of inspiration to contract?

Answer 10

DRG

Question 11

the AP sent by the DRG lasts for ___

Answer 11

2 sec

Question 12

the pre-botzinger complex is also known as the ____generating complex becasue it has ____ cells that set the ___ of normal breathing

Answer 12

rhythm; pacemaker; rhythm

Question 13

where does the input to pacemaker cells likely come from?

Answer 13

DRG

Question 14

the pacemaker cells in the VRG likely drive the rate at which DRG inspiratory neurons ___

Answer 14

fire AP

Question 15

the lower VRG contains fibers that fire during ___

Answer 15

forceful inspiration and expiration

Question 16

medullary inspiratory neurons receive input from the areas in the pons, which act to ___

Answer 16

fine-tune the output and may stop inspiration

Question 17

the pneumotaxic area is located in the ___ pons

Answer 17

superior

Question 18

the apneustic area is located in the ___ pons

Answer 18

inferior

Question 19

the pneumotaxic area modulates activity of the ___ area

Answer 19

apneustic

Question 20

the _____ area sends inhibitory signals to the DRG to terminate inspiration

Answer 20

PA

Question 21

when the PA is activated, the breathing rate is more __

Answer 21

rapid

Question 22

____ is involved in smoothing the transition between inspiration and expiratiion

Answer 22

PA

Question 23

t/f the normal rhythm of breathing can exist without the PA

Answer 23

true

Question 24

the ____ sends stimulatory stimuli to the DRG to prolong inspiration

Answer 24

AA

Question 25

when the AA is active the rate of respiration ___

Answer 25

slows

Question 26

t/f the AA is typically overridden by the PA

Answer 26

true

Question 27

t/f the significance of the AA in adult humans is unclear as its loss poses no significant issues in this group

Answer 27

true

Question 28

what is apneustic breathing? what is the breathing rate per minute? What is this style of breathing associated with?

Answer 28

prolonged inspiration and short expiration; 1.5 bpm; head injury

Question 29

chemoreceptors are sensory receptors that respond to changes in what chemicals?

Answer 29

O2, CO2, H+

Question 30

central chemoreceptors are located on the __

Answer 30

ventral surface of the medulla

Question 31

____ chemoreceptors are important for minute to minute control of breathing

Answer 31

central

Question 32

central chemoreceptors respond to changes in ____ and indirectly to changes in ___

Answer 32

pH of CSF; Pco2 in the artery

Question 33

why do central chemoreceptors respond indirectly to changes in arterial PCO2?

Answer 33

because the CO2 crosses the BBB and eneters the CSF where it is converted to HCO3- and H+

Question 34

peripheral chemioreceptors are located in the ___ and ___

Answer 34

aortic arch (aortic bodies) and bifurcation of the common carotid arteries (carotid bodies)

Question 35

the chemoreceptors in the carotid test the blood before it enters the ___

Answer 35

brain

Question 36

peripheral chemoreceptors trigger increased ventillation in response to ____, ___, or __

Answer 36

decreased Po2, increased Pco2, or increased protons in arterial blood

Question 37

t/f we can tolerate changes in o2 much better than changes in co2

Answer 37

true

Question 38

voluntary control of breathing can be achieved by descending pathways from the ___ to the __

Answer 38

cerebral cortex to the respiratory muscle motor neurons

Question 39

can voluntary breathing be maintained in the presence of involuntary stimulus such as increased co2?

Answer 39

no, its impossible

Question 40

input from the ___ and ___ can stimulate the respiratory system, allowing emotional stimuli to affect respiration

Answer 40

hypothalamus and limbic system

Question 41

physical or chemical stimuli can trigger ___ in the upper airways to trigger a cough or sneezing

Answer 41

irritant receptors

Question 42

what is the diving reflex?

Answer 42

cold water stimulates nasal or facial receptors to stop breathing to protect against aspiration of water

Question 43

what are 4 influences on respiration?

Answer 43

1. voluntary conrtrol 2. emotional state 3. irriation of airways 4. diving reflex

Question 44

what is hypoxia?

Answer 44

dificiency of oxygen at the tissue level

Question 45

what are the 4 classes of hypoxia?

Answer 45

1. hypoxic hypoxia 2. anemic hypoxia 3. ischemic hypoxia 4. histotoxic hypoxia

Question 46

what is hypoxic hypoxia and an example of it?

Answer 46

aterial PO2 is reduced, ex: at high altitude or with airway obstruction

Question 47

what is anemic hypoxia and an example of it?

Answer 47

total blood O2 is reduced due to low RBC, low or abnormal Hb, or CO competition; ex: CO poisoning and anemia

Question 48

what is ischemic hypoxia and an example of it?

Answer 48

blood flow to tissues is too low to provide enough o2 ; ex: due to obstruction of bv

Question 49

what is histotoxic hypoxia and an example of it?

Answer 49

quantity of O2 reaching tissues is normal, but cell is unable to use it due to interference with cells metabolic apparatus EX: cyanide poisoning