control of ventilation

Question 1

what is the description of tidal volume

Answer 1

the volume of air inhaled or exhaled with each breath under resting conditions

Question 2

what is the standard tidal volume in both females and males

Answer 2

500ml

Question 3

describe inspiratory reserve volume

Answer 3

volume of air that can be forcefully inhaled after a normal tidal volume inhalation

Question 4

what is the standard inspiratory reserve volume in a male

Answer 4

3100ml

Question 5

what is the standard inspiratory reserve volume in a female

Answer 5

1900ml

Question 6

describe expiratory reserve volume

Answer 6

volume of air that can be forcefully exhaled after a normal tidal volume exhalation

Question 7

what is the male standard expiratory reserve volume

Answer 7

1200ml

Question 8

what is the standard female expiratory reserve volume

Answer 8

700ml

Question 9

what is the residual volume

Answer 9

amount of air remaining in the lungs after a forced exhalation

Question 10

what is the standard male residual volume

Answer 10

1200ml

Question 11

what is the standard female residual volume

Answer 11

1100ml

Question 12

why does obesity contribute to impaired ventilation

Answer 12

smaller lung volumes
increased neural respiratory drive
increased work of breathing or peepi instrinsic positive end expiratory pressure
increased airway resistance

Question 13

how does obstructive sleep apnoea affect ventilation

Answer 13

the tongue blocks the airway

Question 14

obstructive sleep apnoea can lead to hypoventilation what can this cause

Answer 14

copd
structural kyphosis (chest wall deformity)
neuromuscular disease
morbid obesity

Question 15

acute hypercapnic respiratory failure how does load capacity and neural respiratory drive lead to this

Answer 15

load can be split into resistive elastic and threshold
resistive- airway inflammation bronchospasm sputum
elastic-hyperinflation
threshold -instrinsic positive end expiratory pressure

Question 16

what happens to neural respiratory drive in acute hypercapnic respiratory failure

Answer 16

increased ventilatory response
percieved as breathlessness
capacity- hyperinflation causing muscle shortening and abnormal geometry

Question 17

how can respiratory failure affect the neurological system

Answer 17

it can cause depression and anxiety

Question 18

how can acute hypercapnic respiratory failure affect the cardiovascular system

Answer 18

it can cause congestive heart failure
coronary artery disease

Question 19

how can acute hypercapnic respiratory failure affect the digestive system

Answer 19

gastroesophageal reflux disease

Question 20

how can acute hypercapnic respiratory failure affect the endocrine system

Answer 20

diabetes melitus
diabetes

Question 21

how can acute hypercapnic respiratory failure affect the muscoskeletal system

Answer 21

sarcopenia
muscle weakness
deconditioning

Question 22

how can acute hypercapnic respiratory failure affect the respiratory system

Answer 22

obstructive sleep apnoea
lung cancer
pulmonary hypertension
chronic obstructive pulmonary disease
pulmonary embolism

Question 23

where are central chemoreceptors found

Answer 23

medulla

Question 24

where are peripheral chemoreceptors found

Answer 24

carotid body

Question 25

how does ventilatory control work using the terms sensors effectors and controllers

Answer 25

sensors- lungs chemoreceptors central controllers pons medulla other parts of brain output- effectors- respiratory muscles

Question 26

where is the pneumotaxic centre

Answer 26

in the pons

Question 27

where is dorsal respiratoy group

Answer 27

medulla

Question 28

where is ventral respiratory group

Answer 28

medulla

Question 29

pons has no effect of breathing but is involved in what

Answer 29

higher control

Question 30

what do central chemoreceptors detect

Answer 30

h+ ions

Question 31

what do peripheral chemoreceptors detect

Answer 31

increase pco2 increase h+ ions decreased po2

Question 32

what receptors are pulmonary inputs

Answer 32

irritant receptors-found in epithelium of airways j receptors- found in the alveolar walls near the pulmonary capillaries stretch receptors- found in smooth muscle of airways

Question 33

what nerves do peripheral receptors send signals to the medulla via

Answer 33

glossopharyngealnerve (carotid bodies) vagus nerve (aortic bodies)

Question 34

where are central chemoreceptors located and how do they work

Answer 34

central chemoreceptors are located in the medulla oblongata in the ventrolateral surface near the respiratory centres central chemoreceptors sense changes in the ph of the cerebrospinal fluid which indirectly reflects arterial co2 levels due to co2- h+ conversion

Question 35

how do chemoreceptors perform direct signal transmission

Answer 35

because they are located in the venterolateral surface of the medulla close to the respiratory groups ventral and dorsal respiratory groups they directly stimulate these centres without needing peripheral nerves

Question 36

how do peripheral chemoreceptors transmit signals

Answer 36

via the glossopharyngeal nerve (cranial nerve xi) and the vagus nerve (cranial nerve x) tot eh medulla

Question 37

explain how chemical control of ventilation takes place

Answer 37

plasma paco2 increases paco2 crosses the blood brain barrier into the cerebrospinal fluid stimulus h+in the cerebrospinal fluid stimulates central chemoreceptors there is an increase in minute ventilation few buffers in cerebrospinal fluid small change in paco2 results in large change h+and csf ph responses (20 seconds) increase in ventilation result return to normal paco2

Question 38

in chronic lung disease, increasing ventilation may not be effective at reducing paco2 what happens to in the chemical control of ventilation in such patients

Answer 38

kidneys retain hco3- over the spread of a few days, hco3- enters the csf and neutralises the ph allowing tolerance of higher co2 levels