RS. Control of Breathing

Question 1

what is breathing regulated by?

Answer 1

relaxes (coughing)
volitional control (breath hold)
vocalisation (singing)
emotional events (crying)
physiological challenges (sleep, excercise)

Question 2

what do the neural signals from chemoreceptors to the brain do?

Answer 2

provide feedback on blood PO2, PCO2 and pH

Question 3

what do the neural signals from mechanoreceptors to the brain do?

Answer 3

provide feedback on mechanical status of lungs, chest wall and airways

Question 4

where do the chemoreceptors and mechanoreceptors send neural signals to?

Answer 4

respiratory muscles - to produce rhythmic breathing movements eg. diaphragm and intercostals

upper airway muscles - eg. laryngeal, pharyngeal and tongue

produces rel=flexes to keep airways patent eg. cough, sneeze, gag

Question 5

what are chemoreceptors?

Answer 5

sensory receptors that detect chemical changes in the surrounding environment

Question 6

what is hypoxia?

Answer 6

decrease in oxygen

Question 7

what is hypercapnia?

Answer 7

increase in carbon dioxide

Question 8

what are peripheral chemoreceptors and where are they found?

Answer 8

small, highly vascularised bodies in region of aortic arch and carotid sinuses.

Question 9

how to carotid baroreceptors and chemoreceptors send information to the NTS?

Answer 9

via glossopharyngeal nerve and carotid sinus

Question 10

where is the information sent to thats coming from the aortic/carotid chemoreceptors and baroreceptors?

Answer 10

nucleus tractus solitarius

Question 11

how to aortic baroreceptors and chemoreceptors send information to the NTS?

Answer 11

via vagus nerve

Question 12

where are many important neuronal cell groups (nuclei) with roles in regulation found?

Answer 12

the brainstem

Question 13

what does peripheral chemoreceptors respond to?

Answer 13

decreases in PO2

Question 14

what happens in a hypnotic environment?

Answer 14

• reduction in arterial PO2
• peripheral chemoreceptors stimulated
• neural signal sent from carotid and aortic bodies to NTS in brainstem
• ventilation increases to restore PO2 levels

Question 15

where does a hypoxic response originate?

Answer 15

in the carotid and aortic bodies

Question 16

what are central chemoreceptors?

Answer 16

clusters of neurons in the brainstem that are activated when PCO2 is increased (hypercapnia) or pH decreased

Question 17

what is the sequence of steps when there is a increase in CO2 in the blood?

Answer 17

• increases in arterial PCO2
• central chemoreceptors (brainstem neurones) stimulated
• signals processed and information passed on to neuronal clusters in brainstem involved in generating breathing
• ventilation increases to restore PCO2

Question 18

does a small change in PCO2 or O2 have a bigger effect on ventilation?

Answer 18

PCO2

Question 19

where do hypersonic responses originate from?

Answer 19

central chemoreceptors in brainstem

Question 20

what are mechanoreceptors?

Answer 20

sensory receptors that detect changes in pressure, movement and touch

Question 21

what do mechanoreceptors do in the respiratory system?

Answer 21

detect movement of lung and chest wall

Question 22

what activates mechanoreceptors?

Answer 22

inflation of lungs

Question 23

how do mechanoreceptors send neural signals to the brainstem?

Answer 23

via vagus nerve

Question 24

what are mechanosensory signals essential for?

Answer 24

adapting and adjusting breathing

Question 25

some mechanoreceptors are present on airway smooth muscle. what is its stimulus and reflex?

Answer 25

stimulus = inflation/ distension of airways
reflex = termination of inspiration

Question 26

some mechanoreceptors are present on airway epithelium. what is its stimulus and reflex?

Answer 26

stimulus = rapid lung inflation/deflation or oedema
reflex = sigh or shortened expiration

Question 27

what generates the rhythm of breathing?

Answer 27

clusters of respiratory neurones in brainstem

Question 28

where is the rhythmic breathing signal sent to when it leaves the brainstem?

Answer 28

respiratory muscles

Question 29

give the order of integration go information in the brainstem?

Answer 29

1. NTS receives info from mechanoreceptors and peripheral chemoreceptors
2. info processed in brainstem by respiratory neurons
3. cluster of respiratory neurones in brainstem generate rhythmic of breathing
4. rhythmic signal is sent to respiratory muscles eg. diaphragm

Question 30

what are respiratory pattern generating neurons?

Answer 30

the neurons that generate the pattern of breathing by firing at certain points during the respiratory cycle

Question 31

what are the 2 types of pattern generating neurons?

Answer 31

inspiratory neurons: active during inspiration

expiratory neurons: active during expiration

Question 32

what do respiratory rhythm generating neurones do?

Answer 32

generate the rhythm of the breathing without being stimulated

Question 33

what nerves innervates the diaphragm and where does this nerve exit the spinal cord?

Answer 33

phrenic nerve
cervical spinal cord level 3-5

Question 34

where do the nerves that innervate the intercostal muscles exit the spinal cord?

Answer 34

thoracic spinal cord

Question 35

what can the NTS also be called?

Answer 35

dorsal respiratory group

Question 36

what is the ventral respiratory group?

Answer 36

rhythm generating neurons

Question 37

what are the higher centres and what do they have control of?

Answer 37

• cerebral cortex
• limbic system
• hypothalamus
  have control volitional and emotional breathing

Question 38

why is there a large portion of the motor cortex dedicated to the head?

Answer 38

refined movement

Question 39

what is the 3 respiratory group we don’t know much about?

Answer 39

pontine respiratory group