regulation of respiration

Question 1

what is respiratory center

Answer 1

The respiratory center is composed of several groups of
neurons located bilaterally in the medulla oblongata and
pons of the brain stem,

Question 2

3 neurons present in the respiratory center

Answer 2

(1) a dorsal respiratory group, located in the dorsal portion of
the medulla, which mainly causes inspiration (2) a ventral
respiratory group, located in the ventrolateral part of the medulla, which mainly causes expiration; and (3) the pneumotaxic center, located dorsally in the superior portion of the pons, which mainly controls rate and depth of breathing.

Question 3

what group of neurons plays a fundamental role in the respiration

Answer 3

dorsal group of neurons

Question 4

dorsal group of neurons are present in?

Answer 4

nucleus of tractus solitarius

Question 5

the NTS Is sensory termination of?

Answer 5

vagal and glossopharyngeal nerves

Question 6

The NTS is the sensory termination
of both the vagal and the glossopharyngeal nerves, which
transmit sensory signals into the respiratory center from

Answer 6

1) peripheral chemoreceptors, (2) baroreceptors, and
(3) several types of receptors in the lungs.
4) liver pancreases and multiple parts of GIT

Question 7

INSIPIRATORY neuronal action potentials

Answer 7

these are continuously generated by the dorsal group of neurons which cause the rhythmicity of respiration

Question 8

ramp signal

Answer 8

nervous signals that is transmitted to the inspiratory muscles like the diaphragm is increased gradually and weakly in a ramp manner goes on for 2 secs and then ceases for 3 secs which allows elastic recoil of lungs and causes expiration
so inspiration happens in ramp signals

Question 9

pneumotaxic center is located

Answer 9

nucleus parabrachialis of upper pons

Question 10

function of pneumotaxic center

Answer 10

it controls the switch off button of the inspiratory ramp
it deceases the filling period of lungs that is deceases time of inspiration which in turn deceases time of expiration and increases frequency of respiration

Question 11

ventral respiratory group of neurons are present

Answer 11

rostrally in nucleus ambiguus and caudally at nucleus retroambiguus

Question 12

function of ventral respiratory group of neurons

Answer 12

they remain inactive during normal quite breathing and only act when high pulmonary ventilation is required
causes both expiration and inspiration
sends signals to abdominal muscles to cause heavy expiration when needed

Question 13

located in the

muscular portions of the walls of the bronchi and bronchioles throughout the lungs are

Answer 13

stretch receptors

Question 14

Hering-Breuer

inflation reflex.

Answer 14

stretch receptors that
transmit signals through the vagi into the dorsal respiratory group of neurons when the lungs become overstretched. These signals affect inspiration in much the
same way as signals from the pneumotaxic center; that is,
when the lungs become overly inflated, the stretch receptors activate an appropriate feedback response that
“switches off” the inspiratory ramp and thus stops further
inspiration. This mechanism is called the Hering-Breuer
inflation reflex

Question 15

what acts directly on the respiratory signal and what doesn’t

Answer 15

co2 and h2 acts directly o2 doesnt

Question 16

how o2 levels act of respiratory center

Answer 16

they act through peripheral chemoreceptors present in the carotid and aortic bodies that send signals to respiratory center

Question 17

The sensor neurons in the chemo sensitive area are especially excited

Answer 17

H ions

Question 18

why H+ concentration has less effect in stimulating chemo sensitive neurons

Answer 18

because it cannot cross the brain blood barrier

Question 19

how co2 indirectly stimulates the chemo sensitive neurons

Answer 19

it reacts with water

changes into carbonic acid which dissociates into H+ and HCO3

Question 20

Why does blood CO2 have a more potent effect in
stimulating the chemosensitive neurons than do blood
hydrogen ions?

Answer 20

because of the brain blood barrier does not allow diffusion of H+ IONS
so when pco2 level increases in blood it automatically increases in cerebospinal fluid and fluid of medulla and dissociates into H+ ions which has a direct effect on the chemosensitive areas of the medulla

Question 21

what happens to indirect stimulatory effect of co2 on the respiratory system

Answer 21

it has potent acute effect but weak chronic effect because hco3 combines with the H+ ions which brings the H+ ion concentration back to normal

Question 22

changes of o2 has what effect of respiratory center

Answer 22

it has no direct effect on respiratory center

even if p02 level is decreases adequate amount of 02 in transported to tissues

Question 23

chemoreceptors detect changes in

Answer 23

O2 levels

not co2 levels

Question 24

what do chemoreceptors do

Answer 24

send nervous signals to respiratory center to regulate respiratory activity

Question 25

where are chemoreceptors present and their efferent nerves goes to what and how

Answer 25

carotid body- present at the bifurcation of the carotid artery and its afferent nerves pass though herings nerves to glossopharyngeal nerve to dorsal group of neurons
aortic bodies- present at the aortic arch and efferent nerves pass through vagi to dorsal group of neurons

Question 26

Basic Mechanism of Stimulation of the Chemoreceptors by O2 Deficiency

Answer 26

these bodies of glomus cells which synapse directly or in directly with the nerve endings
they have o2 sensitive K channels which are inactivated when po2 level is less and depolarizes the cells which causes voltage gated calcium channels to open which releases neurotransmitters send signals to nervous system to stimulate respiration

Question 27

main neurotransmitters released by glomus cells

Answer 27

dopamine and acytelcholine

Question 28

main neurotransmitters released by glomus cells during hypoxia

Answer 28

ATP

Question 29

what causes an increase in alveolar ventilation

Answer 29

low po2 level

lower than 100 mm hg of po2

Question 30

acclimatization

Answer 30

Mountain climbers have found that when they ascend a mountain slowly, over a period of days rather than a period of hours, they breathe much more deeply and therefore can withstand far lower atmospheric O2 concentrations than when they ascend rapidly. This phenomenon is called acclimatization

Question 31

what causes intense ventilation during exercise

Answer 31

the neurogenic signals send by brainstem to respiratory center is send simultaneously with the signals send to muscles for contraction

Question 32

Effect of Irritant Receptors in the Airways.

Answer 32

The epithelium of the trachea, bronchi, and bronchioles is supplied
with sensory nerve endings called pulmonary irritant
receptors that are stimulated by many incidents. These
receptors initiate coughing and sneezing,

Question 33

function of lung j receptor

Answer 33

nerve endings present in the alveolar walls juxtaposition to the poulmonary cappilaries are when engorged with blood during congestive heart failure they give a feeling of dyspnea

Question 34

The
activity of the respiratory center may be depressed or even
inactivated by what brain disease and how that dysfunction of brain takes place

Answer 34

due to brain edema which can be due to brain concussion which causes the cerebral arteries to press against the cranial vault
causing the blood supply to stop

Question 35

respiratory depression resulting from

brain edema can be relieved temporarily by

Answer 35

intravenous

injection of hypertonic solutions such as highly concentrated mannitol solution.

Question 36

periodic breathing

Answer 36

persons breaths deeply for a short period of time and then breathes less or not for another interval of time and the cycle repeates

Question 37

disease name for periodic breathing

Answer 37

cheyne strokes breathing

Question 38

The

basic cause of Cheyne-Stokes breathing is

Answer 38

a person overbreathes, thus blowing off too much CO2 from the pulmonary blood while at the same time increasing blood O2, it takes several seconds before the changed pulmonary blood can be transported to the brain and inhibit the excess ventilation. By this time, the person
has already overventilated for an extra few seconds. Therefore, when the overventilated blood finally reaches
the brain respiratory center, the center becomes depressed to an excessive amount, at which point the opposite
cycle begins—that is, CO2 increases and O2 decreases in the alveoli. Again, it takes a few seconds before the brain can respond to these new changes. When the brain does respond, the person breathes hard once again and the cycle repeats

Question 39

apnea means

Answer 39

absence of spontenous breathing

Question 40

why sleep apnea happens

Answer 40

due to an obstruction in the upper airways

or impaired cns respiratory drive

Question 41

Obstructive Sleep Apnea Is Caused by Blockage of the

Upper Airway

Answer 41

muscles of phyrnx keeps the passage open for air to flow but people with narrow air passage way have the issue of closing of the passage with the muscles of pharynx relax during sleeping
which causes snoring, labored breathing followed by a long period of silence apnea (no breathing)

Question 42

other disorders causes by sleep apnea

Answer 42

cardiovascular disease
increased sympathetic activity heart rate
pulmonary and systemic hypertension

Question 43

obstructive sleep apnea usually occurs

Answer 43

people who have fat deposition in the soft tissues of pharynx, enlarged tongues, nasal obstruction, enlarged tonsils or shape of the palate

Question 44

fixation of sleep apnea

Answer 44

tracheostomy, removing of enlarged tongue, CPAP, removing of adenoids and fat from the back of the throat

Question 45

central sleep apnea is caused by

Answer 45

damage to central respiratory center or abnormalities of respiratory neuromuscular apparatus
could be due to stroke