respiration

Question 1

Main function of the respiratory system

Answer 1

Gas exchange between the environment and the circulatory system

Question 2

Internal respiration

Answer 2

Cellular intake of oxygen, ATP generation

Question 3

External respiration

Answer 3

Gas exchange between lungs and blood

Question 4

Normal arterial pO2

Answer 4

85-100mmHg

Question 5

Normal venous pO2

Answer 5

40mmHg

Question 6

Normal arterial pCO2

Answer 6

40mmHg

Question 7

Normal venous pCO2

Answer 7

46mmHg

Question 8

Normal arterial pH

Answer 8

7.4

Question 9

Normal venous pH

Answer 9

7.37

Question 10

Muscles of inspiration
1
2
3
4

Answer 10

1) Sternocleidomastoids
2) Scalenes
3) External intercostals
4) Diaphragm

Question 11

Muscles of expiration

Answer 11

1) Internal intercostals

2) Abdominal muscles

Question 12

Most important muscle of inspiration

Answer 12

Diaphragm

Question 13

What innervates the diaphragm?

Answer 13

Phrenic nerve

Question 14

What innervates the external intercostal muscles?

Answer 14

Intercostal nerves

Question 15

Accessory muscles of inspiration
1
2
3
4

Answer 15

1) Scalene
2) Sternomastoids
3) Nasalis muscle
4) Small muscles in head and neck

Question 16

Function of scalene

Answer 16

Elevate the first 2 ribs

Question 17

Function of sternomastoids

Answer 17

Raise sternum

Question 18

Function of alei nasi

Answer 18

Hold nostrils open (cartilage)

Question 19

Is inspiration active?

Answer 19

Yes

Question 20

Is expiration active?

Answer 20

No, during normal breathing

Question 21

How is expiration passive?

Answer 21

Elastic recoil of elastic lung tissue, inspiratory muscles

Question 22

Is there a neural component of expiration?

Answer 22

Yes

Keep upper airways contracted to slow air leaving the lungs

Question 23

Causes of obstructive sleep apnoea
1
2

Answer 23

1) Unusual upper airway shape

2) Obesity

Question 24

Effects of obstructive sleep apnoea

Answer 24

Daytime somnolence

Hypoxia leading to organ damage

Question 25

Central breathing pattern generator

Answer 25

Pre-Botzinger complex

Question 26

Is inspiration or expiration longer?

Answer 26

Expiration

Question 27

Where is the Pre-Botzinger complex located?

Answer 27

Medulla

Question 28

Which group of neurons control the muscles of inspiration?

Answer 28

Dorsal Respiratory Group

Question 29

``` What does the Dorsal Respiratory Group receive information from? 1 2 3 4 5 ```

Answer 29

1) Pre-Botzinger complex 2) Cranial nerves IX, X 3) Pontine Respiratory Group 4) Medullary chemoreceptors 5) Nucleus Tractus Solitarius

Question 30

How does the Dorsal Respiratory Group connect with the external intercostal muscles and the diaphragm?

Answer 30

Via the intercostal nerves and phrenic nerves

Question 31

Functions of the Ventral Dorsal Group

Answer 31

1) Pacemaker cells in Pre-Botzinger Complex | 2) Active expiration, forced inspiration

Question 32

Neural patterns during quiet breathing

Answer 32

1) Rapid positive feedback loop of active inspiratory neurons during inspiration 2) Inspiratory neurons stop firing at desired tidal volume

Question 33

Function of Pontine Respiratory Group

Answer 33

Coordinate smooth respiratory rhythm Influences start and finish of inspiration

Question 34

What connects to the Pontine Respiratory Group?

Answer 34

Dorsal Respiratory Group

Question 35

Chemical signals triggering ventilation 1 2 3

Answer 35

1) [CO2] 2) [O2] 3) pH

Question 36

Where are the central chemoreceptors and what do they detect?

Answer 36

Ventral surface of medulla Concentrations of CO2, pH

Question 37

``` Where do the central chemoreceptors sample from? 1 2 3 4 ```

Answer 37

From cerebral capillaries Increased [CO2] leads to diffusion from capillary into CSF In CSF, in equilibrium between CO2, H2CO3, H+, HCO3- CO2, H+ detected

Question 38

Where are the peripheral chemoreceptors located?

Answer 38

Carotid body | Aortic body

Question 39

Which nerve attaches to carotid body chemoreceptors?

Answer 39

Glossopharyngeal nerve (IX)

Question 40

Which nerve attaches to aortic body chemoreceptors?

Answer 40

Vagus nerve (X)

Question 41

What do peripheral chemoreceptors detect?

Answer 41

pO2, pCO2

Question 42

Which cells in the carotid and aortic bodies detect pO2?

Answer 42

Glomus cells

Question 43

How do glomus cells detect pO2?

Answer 43

1) Low O2 closes O2-linked K+ channels 2) Cell depolarises 3) Voltage-gated Ca2+ channels open 4) Neurotransmitter release 5) Action potential sent to medullary centres to increase ventillation

Question 44

At what pO2 are peripheral chemoreceptors stimulated?

Answer 44

<60mmHg pO2

Question 45

What is COPD?

Answer 45

Chronic obstructive pulmonary disease

Question 46

Effect of chronic obstructive pulmonary disease on chemoreceptors 1 2 3

Answer 46

1) Chemoreceptors adapt to hypercapnia 2) Chemical stimulus to breathe comes from peripheral chemoreceptors 3) High O2 might cause apnoea

Question 47

Aspects of voluntary breathing control 1 2

Answer 47

1) Cerebral cortex | 2) Limbic system

Question 48

``` Protective reflexes 1 2 3 4 5 ```

Answer 48

1) Bronchoconstriction reflex via irritant receptors in airway epithelium 2) Coughing and sneezing 3) Hering Breuer reflex (pulmonary stretch receptors) 4) Pain and temperature 5) Joint and muscle receptors

Question 49

``` Hering Breuer reflexs 1 2 3 4 5 ```

Answer 49

1) Not present in quiet breathing 2) Involves pulmonary stretch receptors 3) Afferents are conducted by the vagus 4) Inflation reflex: Increase in expiration duration produced by steady lung inflation 5) Deflation reflex: Increase in inspiration duration produced by marked deflation of lung

Question 50

Exercise hyperpnea

Answer 50

Motor cortical activation Muscle spindles types III and IV Maybe triggered by increased CO2 in the lung, K+, H+, lactate, elevated catecholamines, temperature Not related to O2