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Human Epithelial Biology > Introduction to Respiration > Flashcards

Flashcards in Introduction to Respiration Deck (41)
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1
Q

What doesn’t change regardless of the concentration of O2?

A

Partial pressure in different environments - Air, Water, Blood

2
Q

How does gas move? According to partial pressure or according to concentration?

A

Partial pressure from high to low

3
Q

What is the partial pressure in the alveolus?

A

100mmHg

4
Q

What is the concentration of O2 in the alveolus?

A

0.3mlO2/100ml blood

5
Q

What is the partial pressure in the mixed venous blood?

A

40mmHg

6
Q

What is the concentration of O2 in the blood?

A

15.8mlO2/100ml blood

7
Q

Why does O2 move according to partial pressure and not concentration?

A

if it moved according to concentration then O2 would flow out of the body and we would die

8
Q

What is the partial pressure in dry room air?

A

159 mmHg

9
Q

What is the partial pressure in tracheal gas?

A

149mmHg

10
Q

What is the partial pressure in alveolar gas?

A

100mmHg

11
Q

What is the partial pressure of pulmonary veinous blood?

A

98mmHg

12
Q

What type of epithelial cell is the Type 1 alveolar?

A

squamous epithelial for thin blood gas barrier

13
Q

What type of epithelial cell is the type 2 alveolar?

A

cuboidal - stem cell for type 1, produces mucus and surfactant

14
Q

What is the significance of alveolar branching?

A

it reduces resistance throughout the branch network as the diameter narrows
increases the area for gas exchange

15
Q

What is the law associated with resistance in the airway?

A

Poiseuille’s Law

R= 8nl/(pi)r4

16
Q

What does a doubling of total airway diameter do?

A

reduces resistance 16-fold

17
Q

When does gas move into the alveoli?

A

alveolar pressure is less than atmospheric

airways are open

18
Q

When does gas move out of the alveoli?

A

alveolar pressure is greater than atmospheric

airways are open

19
Q

What is alveolar pressure the sum of?

A

elastic recoil pressure

pleural pressure

20
Q

What are the main inspiratory muscles?

A

Diaphragm
External intercostals
Accessory muscles

21
Q

How is the diaphragm innervated?

A

phrenic nerves C3-5

22
Q

How are the external intercostals innervated?

A

intercostal nerves at the rib level

23
Q

What are the accessory muscles?

A

sternocleidomastoid, scalenes

24
Q

As the chest expands, what happens to intrapleural pressure?

A

it falls

25
Q

What are the muscles involved in forced expiration?

A

internal intercostals

abdominal wall

26
Q

What are some of the vital volumes and capacities?

A
Vt - tidal volume
FEV - forced expired volume
FRC
ERV
IRV
Residual volume
27
Q

What is the typical pulmonary volume in males and females?

A

6L in males

4.2L in females

28
Q

How do you calculate vital capacity?

A

IRV+Vt+ERV

29
Q

How do you calculate the FRC?

A

ERV and residual volum

30
Q

How do you calculate the inspiratory capacity?

A

IRV and Vt

31
Q

How do you measure the FRC?

A

helium inhalation method
V2 = V1(C1-C2)/C2
Take known concentration of helium in tank of known volume, take concentration after breathing

32
Q

What is anatomical dead space?

A

component of the lung that does not participate in gas exchange
airway, nasal cavity and mouth

33
Q

How may anatomical dead space vary?

A

Disease
mechanical ventilation
alveolar collapse
species

34
Q

How can you measure anatomical dead space?

A

O2 inhalation method

Carbon dioxide dilution method

35
Q

How does the oxygen inhalation method work?

A

single inspiration of O2
o2 flushes out the gas in the lung which is composed of 75% N2
As subject exhales the breath is initially O2 rich but eventually equilibriates with O2, when a=b that is the dead space

36
Q

How does the CO2 dilution method work?

A

Dead space dilutes the CO2

Vd/Vt = PaCO2 - PexpCO2/PaCO2

37
Q

What is considered a normal FEV1?

A

80% of FVC

38
Q

What is FVC?

A

maximum exhalation under forced conditions

39
Q

What is FEV1?

A

amount of air exhaled in 1s

40
Q

What would be the expected FEV in asthmatics and emphysema?

A

42% ish

41
Q

What would be the expected FEV in restrictive diseases like pulmonary fibrosis?

A

90%