Respiratory System 1

Front 1

What do we need respiration (breathing) for?

Back 1

1) Life

2) Speech

Front 2

What does the upper respiratory tract consist of?

Back 2

Nasal cavity, mouth, pharynx, larynx

Front 3

What does the URS do to air?

Back 3

1) warms it to body temperature

2) humidifies it

3) filters it

Front 4

What does the lower respiratory tract consist of?

Back 4

Trachea, bronchi (and further divisions), bronchiole, alveoli

Front 5

How many divisions are there between the trachea and bronchi?

Back 5

24

Front 6

What is the diameter of the trachea?

Back 6

20mm

Front 7

What is the diameter of the alveoli?

Back 7

0.3mm

Front 8

What are the alveoli sites of?

Back 8

Gas exchange

Front 9

What are the 2 cell types of the alveoli?

Back 9

1) larger

2) smaller

Front 10

What type of pneumocytes are the larger alveoli?

Back 10

Type 1

Front 11

What are the functions of type 1 pneumocytes?

Back 11

Gas diffusion

Front 12

What type of pneumocytes are the smaller alveoli?

Back 12

Type 2

Front 13

What are the functions of type 2 pneumocytes?

Back 13

Release surfactant

Front 14

What does surfactant do?

Back 14

Reduces the surface tension allowing fro expansion

Front 15

What does the connective tissue between alveoli contain that allows the lugs to recoil?

Back 15

Elastin

Front 16

What is Boyles law?

Back 16

An increase in volume = decrease in pressure

A decrease in volume = increase in pressure

Front 17

When the lungs expand, how does air come in?

Back 17

The volume increase and the pressure decreases below atmospheric so air comes in

Front 18

What are the lungs contained in?

Back 18

A pleural sac

Front 19

What opposes lung expansion?

Back 19

Elastic recoil

Front 20

What are the inspiratory muscles involve with causing the thoracic cage to move?

Back 20

External intercostals

Diaphragm

Scalenes

Sternocleidomastoids

Front 21

What muscles are involved with active expiration?

Back 21

Internal intercostals

Abdominal muscles

Front 22

What muscle is the change in thoracic volume mostly due to?

Back 22

Diaphragm (70%)

Front 23

When the diaphragm contracts what happens?

Back 23

It flattens, and lowers by 1.5cm

Front 24

When the diaphragm mis relaxed, what shape is it?

Back 24

Domed

Front 25

What provides 30% of the volume change?

Back 25

Muscles of the rib cage (ribs move up and out)

Front 26

What is the nerve supple to the diaphragm?

Back 26

Phrenic nerve

Front 27

What is FEV1?

Back 27

Forced expiratory volume in one second

The maximum volume of air exhaled in the first second of a forced expiration from a position of full inspiration.

Front 28

What is FEV1 expressed in?

Back 28

Litres at BTPS (body temp. ground level pressure and assuming saturation of air)

Front 29

How does FEV1 change with age?

Back 29

Decreases

Front 30

What is the most common genetic acquired lung disease?

Back 30

Cystic fibrosis - faulty CFTR gene

Front 31

What is the CFTR potentiator Vertex VX-770 used for in CF patients?

Back 31

CF patients with G55ID mutation (5% of CF patients)

Front 32

What did the tablet have an effect on in CF patients?

Back 32

Greater than 10% increase in FEV1 therefore improved pulmonary function (in 2 weeks)

Front 33

What is the normal minute ventilation?

Back 33

5 l/min

Front 34

What is the maximum voluntary ventilation?

Back 34

125-175 l/min

(therefore very large ventilatory reserve)

Front 35

At sea level, what is the atmospheric pressure?

Back 35

760 mmHg

Front 36

In dry air, what is the percentage of O2?

Back 36

21%

Front 37

Therefore what is the partial pressure of O2?

Back 37

160 mmHg

Front 38

What is the effect of water vapour?

Back 38

47 mmHg therefore air = 713 and pO2 = 150 mmHg

Front 39

How many oxygen binding sites does a molecule of haemoglobin have?

Back 39

4

Front 40

What is very useful about oxygen/haemoglobin shown on oxygen/dissociation curves?

Back 40

Haemoglobin is fully saturated with oxygen at low levels (from 60 mmHg)

Front 41

What is arterial pH?

Back 41

7.35-7.45

Front 42

What is arterial pO2?

Back 42

81-100 mmHg

Front 43

What is arterial pCO2?

Back 43

35-45 mmHg

Front 44

What gas is tightly controlled?

Back 44

CO2

Front 45

Where is the central controller of the rhythm cycle generated?

Back 45

Medulla oblongata (brain stem)

Front 46

What feeds into the central rhythm generator?

Back 46

Pons

Front 47

What is DRG?

Back 47

Dorsal respiratory groups

Front 48

What are DRG mainly?

Back 48

Inspiratory neurons

Front 49

Where do the DRG send signals?

Back 49

To the diaphragm and intercostals

Front 50

What cranial nerves bring input from the lungs to the DRG?

Back 50

Vagus and glossophanygeal

Front 51

What is VRG?

Back 51

Ventral respiratory groups

Front 52

What neurons does VRG contain?

Back 52

Both inspiratory and expiratory

Front 53

Where do the VRG send impulses?

Back 53

To the larynx, pharynx, diaphragm and external intercostals

Front 54

What does the pons modify?

Back 54

The output of the medullary centres

Front 55

What provides the chemical control of breathing?

Back 55

Chemoreceptors

Front 56

What are the 2 types of chemoreceptors?

Back 56

1) Central

2) Peripheral

Front 57

Where are central chemoreceptors located?

Back 57

Medulla oblongata

Front 58

What is the brain stem separated from the blood by?

Back 58

The blood brain barrier (BBB)

Front 59

What can cross the BBB?

Back 59

Selectively permeable

CO2 can cross

H+ and HCO3- cannot

Front 60

What is within the area between the BBB and brain stem?

Back 60

CSF (cerebral spinal fluid)

Front 61

What has very little buffering capacity?

Back 61

CSF

Front 62

What enzyme is in the CSF?

Back 62

Carbonic anhydrase

Front 63

If carbonic anhydrase and water combine, what does this form?

Back 63

Acid

Front 64

What does acid cause to happen?

Back 64

Decrease in pH

Front 65

What recognises the change in pH by sensing the change of H+?

Back 65

Central chemoreceptors

Front 66

What is decreased when CO2 is blown off?

Back 66

H+ in the CSF

Front 67

What causes the CO2 to be blown off?

Back 67

A larger respiratory drive

Front 68

What is the normal CSF pH?

Back 68

7.32

Front 69

When CO2 diffuses across the BBB and combines with water, what is produced (via carbonic anhydrase)?

Back 69

H+ and HCO3-

Front 70

What is the choroid plexus?

Back 70

The BBB

Front 71

What does the CP fold into around each capillary?

Back 71

Villi with a brush border of microvilli

Front 72

Where are peripheral chemoreceptors found?

Back 72

In carotid bodies (carotid sinus - neck) and aortic bodies (aortic arch)

Front 73

What do peripheral chemoreceptors respond to?

Back 73

Very low levels of oxygen - such as high altitude (<60 mmHg)

Front 74

Are PC essential?

Back 74

No as they can be denervated

Front 75

What types of cells do carotid bodies have?

Back 75

Type 1 and type 2 cells

Front 76

What are type 2 cells?

Back 76

Thy are pluripotent

Front 77

What can type 2 cells differentiate into?

Back 77

Type 1 cells

Front 78

What do type 1 cells have?

Back 78

Chemical transmitters that respond to low levels of oxygen

Front 79

What happens at low levels of oxygen?

Back 79

Release transmitters from vesicles causing APs

Front 80

Where do the APs feed into?

Back 80

The central control mechanisms